1.
Alapaha River
–
The Alapaha River /əˈlæpəhɑː/ is a 202-mile-long river in southern Georgia and northern Florida in the United States. It is a tributary of the Suwannee River, which flows to the Gulf of Mexico, the Hernando de Soto expedition narrative records mention a Yupaha village they encountered after they left Apalachee, the sound of which is suggestive of the Alapaha, a tributary of the Suwanee. Another reference to a village of Atapaha so closely resembles Alapaha that it is reasonable to suppose they are the same, augustine, Florida, probably on the Alapaha River. In the 1840s a German travel writer, Friedrich Gerstäcker wrote a novel called Alapaha, or the Renegades of the Border. A translation of this novel was published in the 1870s as #67 in a series of American narratives published by Beadle. During the American Civil War, the swamps along the Alapaha River in Berrien, Irwin, along its course it passes the Georgia towns of Rebecca, Alapaha, Willacoochee, Lakeland, and Statenville. Near Willacoochee, Georgia, the Alapaha collects the Willacoochee River, in Florida, it collects the Alapahoochee River and the short Little Alapaha River, which rises in Echols County, Georgia, and flows southwestward. The Alapaha River is an intermittent river for part of its course, during periods of low volume, the river disappears underground and becomes a subterranean river. At approximately 2.3 miles downstream from Jennings, Florida is a river sinkhole variously known as the Alapaha River Sink, Suck Hole and it is located at 30. 5855009°N83. 0528016°W /30.5855009, -83.0528016. A short distance away from the Devils Dens, the Dead River enters into the Alapaha River and it is a usually dry river bed with a number of sinkholes, including the Dead River Sink. A few more miles downstream is a sinkhole known as the Dead River Sink or the Siphon. At the latter point during the periods of low water flow, the Alapaha River later reappears at the Alapaha River Rise, which is about a half mile upstream from the confluence of the Alapaha River and the Suwanee River. During a period of low rainfall over 11 miles of the riverbed can be dry as the river goes underground, the United States Board on Geographic Names settled on Alapaha River as the streams name in 1891. According to the Geographic Names Information System, it has also known as
2.
Jennings, Florida
–
Jennings is a town in Hamilton County, Florida, United States. The population was 833 at the 2000 census, as of 2004, the population recorded by the U. S. Census Bureau was 843. Jennings is located at 30°36′11″N 83°6′8″W, according to the United States Census Bureau, the town has a total area of 1.8 square miles, all land. As of the census of 2000, there were 833 people,282 households, the population density was 461.3 people per square mile. There were 321 housing units at a density of 177.8 per square mile. The racial makeup of the town was 43. 70% White,43. 10% African American,0. 60% Native American,0. 60% Asian,10. 08% from other races, hispanic or Latino of any race were 22. 69% of the population. 23. 0% of all households were made up of individuals and 11. 7% had someone living alone who was 65 years of age or older, the average household size was 2.89 and the average family size was 3.34. In the town, the population was out with 30. 6% under the age of 18,9. 0% from 18 to 24,25. 7% from 25 to 44,22. 4% from 45 to 64. The median age was 32 years, for every 100 females there were 98.8 males. For every 100 females age 18 and over, there were 99.3 males, the median income for a household in the town was $25,714, and the median income for a family was $25,938. Males had an income of $25,577 versus $15,982 for females. The per capita income for the town was $12,195, about 23. 8% of families and 30. 8% of the population were below the poverty line, including 42. 9% of those under age 18 and 20. 0% of those age 65 or over. North Hamilton Elementary will be consolidated into a new school, Hamilton County Elementary School. Its opening is scheduled for August 2017, the Suwannee River Regional Library System operates the Jennings Public Library
3.
Sinkhole
–
A sinkhole, also known as a cenote, sink, sink-hole, shakehole, swallet, swallow hole, or doline, is a depression or hole in the ground caused by some form of collapse of the surface layer. Most are caused by karst processes—for example, the dissolution of carbonate rocks or suffosion processes. Sinkholes vary in size from 1 to 600 m both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms, sinkholes may form gradually or suddenly, and are found worldwide. Sinkholes may capture surface drainage from running or standing water, but may form in high. Sinkholes that capture drainage can hold it in limestone caves. These caves may drain into tributaries of larger rivers, the formation of sinkholes involves natural processes of erosion or gradual removal of slightly soluble bedrock by percolating water, the collapse of a cave roof, or a lowering of the water table. Sinkholes often form through the process of suffosion, for example, groundwater may dissolve the carbonate cement holding the sandstone particles together and then carry away the lax particles, gradually forming a void. Occasionally a sinkhole may exhibit a visible opening into a cave below, sinkholes also occur in sandstone and quartzite terrains. As the rock dissolves, spaces and caverns develop underground and these sinkholes can be dramatic, because the surface land usually stays intact until there is not enough support. Then, a collapse of the land surface can occur. Sinkholes also form from human activity, such as the collapse of abandoned mines and salt cavern storage in salt domes in places like Louisiana, Mississippi, more commonly, sinkholes occur in urban areas due to water main breaks or sewer collapses when old pipes give way. They can also occur from the overpumping and extraction of groundwater, sinkholes can also form when natural water-drainage patterns are changed and new water-diversion systems are developed. Sinkholes tend to occur in karst landscapes, karst landscapes can have up to thousands of sinkholes within a small area, giving the landscape a pock-marked appearance. These sinkholes drain all the water, so there are only subterranean rivers in these areas, examples of karst landscapes with a plethora of massive sinkholes include Khammouan Mountains and Mamo Plateau. The largest known sinkholes formed in sandstone are Sima Humboldt and Sima Martel in Venezuela, some sinkholes form in thick layers of homogenous limestone. On the contact of limestone and insoluble rock below it, powerful underground rivers may form, in such conditions, the largest known sinkholes of the world have formed, like the 662-metre deep Xiaozhai Tiankeng, giant sótanos in Querétaro and San Luis Potosí states in Mexico and others. The state of Florida in the United States is known for having frequent sinkhole collapses, the Murge area in southern Italy also has numerous sinkholes. Sinkholes can be formed in retention ponds from large amounts of rain, an analysis of a case of sinkhole formation under a retention pond due to a large amount of rain can be seen in a sinkhole collapse study
4.
Floridan aquifer
–
It underlies the entire state of Florida and parts of Alabama, Georgia, Mississippi, and South Carolina. The Floridan aquifer system is one of the worlds most productive aquifers, according to the U. S. Geological Survey, total withdrawals from the Floridan aquifer system in 2000 were ranked 5th highest of all principle aquifers in the Nation at 3,640 million gallons per day. Of the total, 49% was used for irrigation, 33% was used for water supply, 14% was used for industrial purposes. In 1936, geologist Victor Timothy Stringfield first identified the existence of the Floridan Aquifer in peninsular Florida and referred to the carbonate units as the principal artesian formations. In 1944, M. A. Warren of the Georgia Geological Survey described an extension of system in south Georgia. In 1953 and 1966 Stringfield also applied the term principal artesian aquifer to these rocks, with additional information collection, more zones of high and low hydraulic conductivity have been identified. As a result, the name Floridan Aquifer has evolved into Floridan aquifer system, withdrawals from the Floridan aquifer system began in 1887 when the City of Savannah, Georgia, began to supplement surface water withdrawals from the Savannah River with groundwater. Over time, the number of wells increased, as did the finished depths, industrial supply for pulp and paper mills became a large proportion of the water withdrawn starting in the late 1930s. In the 1950s, all municipal, domestic, and industrial supply and about half of agricultural supply in Orlando, groundwater withdrawals from the Floridan aquifer system increased steadily from 630 Mgal/d in 1950 to 3,430 Mgal/d in 1990. Much of the increase was due to increased agricultural demand, the Upper Floridan aquifer contains freshwater over much of its extent, though is brackish and saline south of Lake Okeechobee. The Floridan aquifer system crops out in central and southern Georgia where the limestone, the aquifer system generally dips below land surface to the south where it becomes buried beneath surficial sand deposits and clay. In areas depicted in brown in the image at the right and these regions particularly prone to sinkhole activity due to the proximity of the karstified limestone aquifer to land surface. Some of the fractures/conduits within the aquifer are large enough for divers to swim through. In west-central Florida, north Florida, and along the margin of the system, the limestone crops out. Where low-permeability clays of the upper confining unit are present and substantial, low permeability limestone rocks of Paleocene age form the base of the Floridan aquifer system. The Floridan aquifer system ranges in thickness from less than 100 feet in areas where the rocks pinch out to more than 3,700 feet in southwestern Florida. Where the Floridan aquifer system is at or near surface, clays are thin or absent and dissolution of the limestone is intensified and many springs. Transmissivity of the aquifer in karstified areas such as these is much higher owing to the development of large, Springs form where the water pressure is great enough for the groundwater to flow out on the land surface
5.
Groundwater
–
Groundwater is the water present beneath Earths surface in soil pore spaces and in the fractures of rock formations. A unit of rock or a deposit is called an aquifer when it can yield a usable quantity of water. The depth at which pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from, and eventually flows to, the naturally, natural discharge often occurs at springs and seeps. Groundwater is also withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, Groundwater is hypothesized to provide lubrication that can possibly influence the movement of faults. It is likely that much of Earths subsurface contains some water, Groundwater may not be confined only to Earth. The formation of some of the landforms observed on Mars may have influenced by groundwater. There is also evidence that water may also exist in the subsurface of Jupiters moon Europa. Groundwater is often cheaper, more convenient and less vulnerable to pollution than surface water, therefore, it is commonly used for public water supplies. For example, groundwater provides the largest source of water storage in the United States. Underground reservoirs contain far more water than the capacity of all surface reservoirs and lakes in the US, many municipal water supplies are derived solely from groundwater. Polluted groundwater is less visible, but more difficult to clean up, than pollution in rivers, Groundwater pollution most often results from improper disposal of wastes on land. An aquifer is a layer of substrate that contains and transmits groundwater. When water can flow directly between the surface and the zone of an aquifer, the aquifer is unconfined. The deeper parts of unconfined aquifers are more saturated since gravity causes water to flow downward. The upper level of this layer of an unconfined aquifer is called the water table or phreatic surface. Below the water table, where in general all pore spaces are saturated with water, is the phreatic zone, substrate with low porosity that permits limited transmission of groundwater is known as an aquitard
6.
Water
–
Water is a transparent and nearly colorless chemical substance that is the main constituent of Earths streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is H2O, meaning that its molecule contains one oxygen, Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure, but it often refers also to its solid state or its gaseous state. It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, Water covers 71% of the Earths surface. It is vital for all forms of life. Only 2. 5% of this water is freshwater, and 98. 8% of that water is in ice and groundwater. Less than 0. 3% of all freshwater is in rivers, lakes, and the atmosphere, a greater quantity of water is found in the earths interior. Water on Earth moves continually through the cycle of evaporation and transpiration, condensation, precipitation. Evaporation and transpiration contribute to the precipitation over land, large amounts of water are also chemically combined or adsorbed in hydrated minerals. Safe drinking water is essential to humans and other even though it provides no calories or organic nutrients. There is a correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in developing regions of the world. Water plays an important role in the world economy, approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, rivers, lakes, large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a variety of chemical substances, as such it is widely used in industrial processes. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, Water is a liquid at the temperatures and pressures that are most adequate for life. Specifically, at atmospheric pressure of 1 bar, water is a liquid between the temperatures of 273.15 K and 373.15 K
7.
River
–
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases a river flows into the ground and becomes dry at the end of its course without reaching another body of water, small rivers can be referred to using names such as stream, creek, brook, rivulet, and rill. There are no official definitions for the term river as applied to geographic features. Many names for small rivers are specific to geographic location, examples are run in parts of the United States, burn in Scotland and northeast England. Sometimes a river is defined as being larger than a creek, but not always, Rivers are part of the hydrological cycle. Potamology is the study of rivers while limnology is the study of inland waters in general. Extraterrestrial rivers of liquid hydrocarbons have recently found on Titan. Channels may indicate past rivers on other planets, specifically outflow channels on Mars and rivers are theorised to exist on planets, a river begins at a source, follows a path called a course, and ends at a mouth or mouths. The water in a river is confined to a channel. In larger rivers there is also a wider floodplain shaped by flood-waters over-topping the channel. Floodplains may be wide in relation to the size of the river channel. This distinction between river channel and floodplain can be blurred, especially in areas where the floodplain of a river channel can become greatly developed by housing. Rivers can flow down mountains, through valleys or along plains, the term upriver refers to the direction towards the source of the river, i. e. against the direction of flow. Likewise, the term describes the direction towards the mouth of the river. The term left bank refers to the bank in the direction of flow. The river channel typically contains a stream of water, but some rivers flow as several interconnecting streams of water. Extensive braided rivers are now found in only a few regions worldwide and they also occur on peneplains and some of the larger river deltas. Anastamosing rivers are similar to braided rivers and are quite rare
8.
Lake
–
A lake is an area of variable size filled with water, localized in a basin, that is surrounded by land, apart from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, and therefore are distinct from lagoons, Lakes can be contrasted with rivers or streams, which are usually flowing. Most lakes are fed and drained by rivers and streams, natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers, in some parts of the world there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will fill in with sediments or spill out of the basin containing them. The word lake comes from Middle English lake, from Old English lacu, from Proto-Germanic *lakō, cognates include Dutch laak, Middle Low German lāke as in, de, Moorlake, de, Wolfslake, de, Butterlake, German Lache, and Icelandic lækur. Also related are the English words leak and leach, none of these definitions completely excludes ponds and all are difficult to measure. For this reason, simple size-based definitions are used to separate ponds. One definition of lake is a body of water of 2 hectares or more in area, however, others have defined lakes as waterbodies of 5 hectares and above, or 8 hectares and above. Charles Elton, one of the founders of ecology, regarded lakes as waterbodies of 40 hectares or more. The term lake is used to describe a feature such as Lake Eyre. In common usage, many bear names ending with the word pond. One textbook illustrates this point with the following, In Newfoundland, for example, almost every lake is called a pond, whereas in Wisconsin, the majority of lakes on Earth are fresh water, and most lie in the Northern Hemisphere at higher latitudes. Canada, with a drainage system has an estimated 31,752 lakes larger than 3 square kilometres and an unknown total number of lakes. Finland has 187,888 lakes 500 square metres or larger, most lakes have at least one natural outflow in the form of a river or stream, which maintain a lakes average level by allowing the drainage of excess water. Some lakes do not have an outflow and lose water solely by evaporation or underground seepage or both. Many lakes are artificial and are constructed for power generation, aesthetic purposes, recreational purposes, industrial use. Globally, lakes are greatly outnumbered by ponds, of an estimated 304 million standing water bodies worldwide, 91% are 1 hectare or less in area
9.
Wetland
–
A wetland is a land area that is saturated with water, either permanently or seasonally, such that it takes on the characteristics of a distinct ecosystem. The primary factor that distinguishes wetlands from other forms or water bodies is the characteristic vegetation of aquatic plants. Wetlands play a number of roles in the environment, principally water purification, flood control, carbon sink, Wetlands are also considered the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal life. Wetlands occur naturally on every continent except Antarctica, the largest including the Amazon River basin, the West Siberian Plain, the water found in wetlands can be freshwater, brackish, or saltwater. The main wetland types include swamps, marshes, bogs, and fens, and sub-types include mangrove, carr, pocosin, the UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within wetland systems than any other ecosystem on Earth. International conservation efforts are being used in conjunction with the development of rapid assessment tools to people about wetland issues. Constructed wetlands can be used to treat municipal and industrial wastewater as well as stormwater runoff and they may also play a role in water-sensitive urban design. A patch of land that develops pools of water after a storm would not be considered a wetland. Wetlands have unique characteristics, they are distinguished from other water bodies or landforms based on their water level. Specifically, wetlands are characterized as having a table that stands at or near the land surface for a long enough period each year to support aquatic plants. A more concise definition is a community composed of hydric soil, Wetlands have also been described as ecotones, providing a transition between dry land and water bodies. In environmental decision-making, there are subsets of definitions that are agreed upon to make regulatory and policy decisions. A wetland is an ecosystem that arises when inundation by water produces soils dominated by anaerobic processes, There are four main kinds of wetlands – marsh, swamp, bog and fen. Some experts also recognize wet meadows and aquatic ecosystems as additional wetland types, the largest wetlands in the world include the swamp forests of the Amazon and the peatlands of Siberia. Under the Ramsar international wetland conservation treaty, wetlands are defined as follows, Article 2.1, may incorporate riparian and coastal zones adjacent to the wetlands, and islands or bodies of marine water deeper than six metres at low tide lying within the wetlands. Although the general definition given above applies around the world, each county, Wetlands generally include swamps, marshes, bogs and similar areas. This definition has been used in the enforcement of the Clean Water Act, some US states, such as Massachusetts and New York, have separate definitions that may differ from the federal governments. It is not uncommon for a wetland to be dry for long portions of the growing season, the most important factor producing wetlands is flooding
10.
Ocean
–
An ocean is a body of saline water that composes much of a planets hydrosphere. On Earth, an ocean is one of the major divisions of the World Ocean. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, the word sea is often used interchangeably with ocean in American English but, strictly speaking, a sea is a body of saline water partly or fully enclosed by land. The ocean contains 97% of Earths water, and oceanographers have stated that less than 5% of the World Ocean has been explored, the total volume is approximately 1.35 billion cubic kilometers with an average depth of nearly 3,700 meters. As the world ocean is the component of Earths hydrosphere, it is integral to all known life, forms part of the carbon cycle. The world ocean is the habitat of 230,000 known species, but because much of it is unexplored, the origin of Earths oceans remains unknown, oceans are thought to have formed in the Hadean period and may have been the impetus for the emergence of life. Extraterrestrial oceans may be composed of water or other elements and compounds, the only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan, although there is evidence for the existence of oceans elsewhere in the Solar System. Early in their histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, compounds such as salts and ammonia dissolved in water lower its freezing point so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice. Unconfirmed oceans are speculated beneath the surface of many planets and natural satellites, notably. The Solar Systems giant planets are thought to have liquid atmospheric layers of yet to be confirmed compositions. Oceans may also exist on exoplanets and exomoons, including surface oceans of water within a circumstellar habitable zone. Ocean planets are a type of planet with a surface completely covered with liquid. The concept of Ōkeanós has an Indo-European connection, Greek Ōkeanós has been compared to the Vedic epithet ā-śáyāna-, predicated of the dragon Vṛtra-, who captured the cows/rivers. Related to this notion, the Okeanos is represented with a dragon-tail on some early Greek vases, though generally described as several separate oceans, these waters comprise one global, interconnected body of salt water sometimes referred to as the World Ocean or global ocean. This concept of a body of water with relatively free interchange among its parts is of fundamental importance to oceanography. The major oceanic divisions – listed below in descending order of area and volume – are defined in part by the continents, various archipelagos, Oceans are fringed by smaller, adjoining bodies of water such as seas, gulfs, bays, bights, and straits. The Mid-Oceanic Ridge of the World are connected and form the Ocean Ridge, the continuous mountain range is 65,000 km long, and the total length of the oceanic ridge system is 80,000 km long
11.
Precipitation
–
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel, Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and precipitates. Thus, fog and mist are not precipitation but suspensions, because the vapor does not condense sufficiently to precipitate. Two processes, possibly acting together, can lead to air becoming saturated, Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called showers, moisture that is lifted or otherwise forced to rise over a layer of sub-freezing air at the surface may be condensed into clouds and rain. This process is active when freezing rain is occurring. A stationary front is often present near the area of freezing rain, provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus. Eventually, the droplets will grow large enough to form raindrops. Lake-effect snowfall can be locally heavy, thundersnow is possible within a cyclones comma head and within lake effect precipitation bands. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation, on the leeward side of mountains, desert climates can exist due to the dry air caused by compressional heating. The movement of the trough, or intertropical convergence zone. Precipitation is a component of the water cycle, and is responsible for depositing the fresh water on the planet. Approximately 505,000 cubic kilometres of water falls as precipitation each year,398,000 cubic kilometres of it over the oceans and 107,000 cubic kilometres over land. Given the Earths surface area, that means the globally averaged annual precipitation is 990 millimetres, Climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes. Precipitation may occur on celestial bodies, e. g. when it gets cold, Mars has precipitation which most likely takes the form of frost. Precipitation is a component of the water cycle, and is responsible for depositing most of the fresh water on the planet. Approximately 505,000 km3 of water falls as precipitation each year,398,000 km3 of it over the oceans, given the Earths surface area, that means the globally averaged annual precipitation is 990 millimetres. Mechanisms of producing precipitation include convective, stratiform, and orographic rainfall, Precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice
12.
Evaporation
–
Evaporation is a type of vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase that is not saturated with the evaporating substance. The other type of vaporization is boiling, which is characterized by bubbles of saturated vapor forming in the liquid phase, steam produced in a boiler is another example of evaporation occurring in a saturated vapor phase. Evaporation that occurs directly from the solid phase below the melting point, on average, a fraction of the molecules in a glass of water have enough heat energy to escape from the liquid. The water in the glass will be cooled by the evaporation until an equilibrium is reached where the air supplies the amount of heat removed by the evaporating water, in an enclosed environment the water would evaporate until the air is saturated. With sufficient temperature, the liquid would turn into vapor quickly, when the molecules collide, they transfer energy to each other in varying degrees, based on how they collide. Sometimes the transfer is so one-sided for a molecule near the surface that it ends up with energy to escape. Evaporation is an part of the water cycle. The sun drives evaporation of water from oceans, lakes, moisture in the soil, in hydrology, evaporation and transpiration are collectively termed evapotranspiration. Evaporation of water occurs when the surface of the liquid is exposed, allowing molecules to escape and form water vapor, when only a small proportion of the molecules meet these criteria, the rate of evaporation is low. Since the kinetic energy of a molecule is proportional to its temperature, as the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, and the temperature of the liquid decreases. This phenomenon is also called evaporative cooling and this is why evaporating sweat cools the human body. Evaporation also tends to proceed quickly with higher flow rates between the gaseous and liquid phase and in liquids with higher vapor pressure. For example, laundry on a line will dry more rapidly on a windy day than on a still day. Three key parts to evaporation are heat, atmospheric pressure, on a molecular level, there is no strict boundary between the liquid state and the vapor state. Instead, there is a Knudsen layer, where the phase is undetermined, because this layer is only a few molecules thick, at a macroscopic scale a clear phase transition interface cannot be seen. It is just that the process is slower and thus significantly less visible. If evaporation takes place in an area, the escaping molecules accumulate as a vapor above the liquid. Many of the return to the liquid, with returning molecules becoming more frequent as the density
13.
Soil mechanics
–
Soil mechanics is a branch of soil physics and engineering mechanics that describes the behavior of soils. It differs from fluid mechanics and solid mechanics in the sense that soils consist of a mixture of fluids and particles but soil may also contain organic solids. Soil mechanics is used to analyze the deformations of and flow of fluids within natural and man-made structures that are supported on or made of soil, example applications are building and bridge foundations, retaining walls, dams, and buried pipeline systems. Principles of soil mechanics are used in related disciplines such as engineering geology, geophysical engineering, coastal engineering, agricultural engineering, hydrology. The shear strength of soils is primarily derived from friction between the particles and interlocking, which are sensitive to the effective stress. The article concludes with examples of applications of the principles of soil mechanics such as slope stability, lateral earth pressure on retaining walls. The primary mechanism of soil creation is the weathering of rock, all rock types may be broken down into small particles to create soil. Weathering mechanisms are physical weathering, chemical weathering, and biological weathering Human activities such as excavation, blasting, physical weathering includes temperature effects, freeze and thaw of water in cracks, rain, wind, impact and other mechanisms. Chemical weathering includes dissolution of matter composing a rock and precipitation in the form of another mineral, clay minerals, for example can be formed by weathering of feldspar, which is the most common mineral present in igneous rock. The most common constituent of silt and sand is quartz, also called silica. The reason that feldspar is most common in rocks but silicon is more prevalent in soils is that feldspar is much more soluble than silica, silt, Sand, and Gravel are basically little pieces of broken rocks. Particles larger than gravel are called cobbles and boulders, Soil deposits are affected by the mechanism of transport and deposition to their location. Soils that are not transported are called residual soils—they exist at the location as the rock from which they were generated. Decomposed granite is an example of a residual soil. The common mechanisms of transport are the actions of gravity, ice, water, wind blown soils include dune sands and loess. Water carries particles of different size depending on the speed of the water, silt and clay may settle out in a lake, and gravel and sand collect at the bottom of a river bed. Wind blown soil deposits also tend to be sorted according to their grain size. Erosion at the base of glaciers is powerful enough to pick up rocks and boulders as well as soil
14.
Transpiration
–
Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only an amount of water taken up by the roots is used for growth. The remaining 97–99. 5% is lost by transpiration and guttation, leaf surfaces are dotted with pores called stomata, and in most plants they are more numerous on the undersides of the foliage. The stomata are bordered by guard cells and their stomatal accessory cells that open, transpiration also cools plants, changes osmotic pressure of cells, and enables mass flow of mineral nutrients and water from roots to shoots. Two major factors influence the rate of flow from the soil to the roots, the hydraulic conductivity of the soil. Both of these factors influence the rate of flow of water moving from the roots to the stomatal pores in the leaves via the xylem. Mass flow of water from the roots to the leaves is driven in part by capillary action. This movement lowers the potential in the leaf airspace and causes evaporation of liquid water from the mesophyll cell walls. This evaporation increases the tension on the water menisci in the cell walls, water is absorbed at the roots by osmosis, and any dissolved mineral nutrients travel with it through the xylem. The Cohesion-tension theory explains how leaves pull water through the xylem, water molecules stick together, or exhibit cohesion. As a water molecule evaporates from the surface of the leaf, it pulls on the adjacent water molecule, plants regulate the rate of transpiration by controlling the size of the stomatal apertures. The rate of transpiration is also influenced by the demand of the atmosphere surrounding the leaf such as boundary layer conductance, humidity, temperature, wind. Soil water supply and soil temperature can influence stomatal opening, the amount of water lost by a plant also depends on its size and the amount of water absorbed at the roots. Transpiration accounts for most of the loss by a plant by the leaves. Transpiration serves to evaporatively cool plants, as the water carries away heat energy due to its large latent heat of vaporization of 2260 kJ per litre. During a growing season, a leaf will transpire many times more water than its own weight, an acre of corn gives off about 3, 000–4,000 gallons of water each day, and a large oak tree can transpire 40,000 gallons per year. The transpiration ratio is the ratio of the mass of water transpired to the mass of dry matter produced, transpiration rates of plants can be measured by a number of techniques, including potometers, lysimeters, porometers, photosynthesis systems and thermometric sap flow sensors. Isotope measurements indicate transpiration is the component of evapotranspiration
15.
Salinity
–
Salinity is the saltiness or amount of salt dissolved in a body of water. This is usually measured in g salt k g sea water, a contour line of constant salinity is called an isohaline – or sometimes isohale. Salinity in rivers, lakes, and the ocean is conceptually simple, conceptually the salinity is the quantity of dissolved salt content of the water. Salts are compounds like sodium chloride, magnesium sulfate, potassium nitrate, the concentration of dissolved chloride ions is sometimes referred to as chlorinity. Operationally, dissolved matter is defined as that which can pass through a fine filter. Salinity can be expressed in the form of a mass fraction, Seawater typically has a mass salinity of around 35 g/kg, although lower values are typical near coasts where rivers enter the ocean. Rivers and lakes can have a range of salinities, from less than 0.01 g/kg to a few g/kg. The Dead Sea has a salinity of more than 200 g/kg, whatever pore size is used in the definition, the resulting salinity value of a given sample of natural water will not vary by more than a few percent. A bottled seawater product known as IAPSO Standard Seawater is used by oceanographers to standardize their measurements with enough precision to meet this requirement, measurement and definition difficulties arise because natural waters contain a complex mixture of many different elements from different sources in different molecular forms. The chemical properties of some of these depend on temperature and pressure. Many of these forms are difficult to measure with high accuracy, different practical definitions of salinity result from different attempts to account for these problems, to different levels of precision, while still remaining reasonably easy to use. For many purposes this sum can be limited to a set of eight major ions in natural waters, the major ions dominate the inorganic composition of most natural waters. Exceptions include some pit lakes and waters from some hydrothermal springs, the concentrations of dissolved gases like oxygen and nitrogen are not usually included in descriptions of salinity. However, carbon dioxide gas, which when dissolved is partially converted into carbonates and bicarbonates, is often included. Silicon in the form of acid, which usually appears as a neutral molecule in the pH range of most natural waters. The term salinity is, for oceanographers, usually associated with one of a set of measurement techniques. As the dominant techniques evolve, so do different descriptions of salinity, the distinctions between these different descriptions are important to physical oceanographers but are obscure and confusing to nonspecialists. Salinities were largely measured using titration-based techniques before the 1980s, titration with silver nitrate could be used to determine the concentration of halide ions to give a chlorinity
16.
Aquifer
–
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials from which groundwater can be extracted using a water well. The study of flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include aquitard, which is a bed of low permeability along an aquifer, and aquiclude, if the impermeable area overlies the aquifer, pressure could cause it to become a confined aquifer. Aquifers may occur at various depths and those closer to the surface are not only more likely to be used for water supply and irrigation, but are also more likely to be topped up by the local rainfall. Many desert areas have limestone hills or mountains within them or close to them that can be exploited as groundwater resources, overexploitation can lead to the exceeding of the practical sustained yield, i. e. more water is taken out than can be replenished. The beach provides a model to help visualize an aquifer, if a hole is dug into the sand, very wet or saturated sand will be located at a shallow depth. This hole is a well, the wet sand represents an aquifer. In 2013 large freshwater aquifers were discovered under continental shelves off Australia, China, North America and they contain an estimated half a million cubic kilometers of “low salinity” water that could be economically processed into potable water. The reserves formed when ocean levels were lower and rainwater made its way into the ground in areas that were not submerged until the ice age ended 20,000 years ago. The volume is estimated to be 100x the amount of extracted from other aquifers since 1900. The above diagram indicates typical flow directions in a view of a simple confined or unconfined aquifer system. The system shows two aquifers with one aquitard between them, surrounded by the bedrock aquiclude, which is in contact with a gaining stream, the water table and unsaturated zone are also illustrated. An aquitard is a zone within the earth that restricts the flow of groundwater from one aquifer to another, an aquitard can sometimes, if completely impermeable, be called an aquiclude or aquifuge. Aquitards are composed of layers of clay or non-porous rock with low hydraulic conductivity. Groundwater can be found at every point in the Earths shallow subsurface to some degree. Saturated means the head of the water is greater than atmospheric pressure. The definition of the table is the surface where the pressure head is equal to atmospheric pressure. Unsaturated conditions occur above the table where the pressure head is negative
17.
Surface runoff
–
Surface runoff is the flow of water that occurs when excess stormwater, meltwater, or other sources flows over the Earths surface. Surface runoff is a component of the water cycle. It is the agent in soil erosion by water. Runoff that occurs on the surface before reaching a channel is also called a nonpoint source. If a nonpoint source contains man-made contaminants, or natural forms of pollution the runoff is called nonpoint source pollution, a land area which produces runoff that drains to a common point is called a drainage basin. When runoff flows along the ground, it can pick up soil contaminants including petroleum, pesticides, surface runoff can be generated either by rainfall, snowfall or by the melting of snow, or glaciers. Snow and glacier melt occur only in areas cold enough for these to form permanently, typically snowmelt will peak in the spring and glacier melt in the summer, leading to pronounced flow maxima in rivers affected by them. The determining factor of the rate of melting of snow or glaciers is both air temperature and the duration of sunlight, in high mountain regions, streams frequently rise on sunny days and fall on cloudy ones for this reason. In areas where there is no snow, runoff will come from rainfall, however, not all rainfall will produce runoff because storage from soils can absorb light showers. This occurs when the rate of rainfall on a surface exceeds the rate at which water can infiltrate the ground and this is called flooding excess overland flow, Hortonian overland flow, or unsaturated overland flow. This more commonly occurs in arid and semi-arid regions, where rainfall intensities are high and this occurs largely in city areas where pavements prevent water from flooding. When the soil is saturated and the depression storage filled, and rain continues to fall, the level of antecedent soil moisture is one factor affecting the time until soil becomes saturated. This runoff is called saturation excess overland flow or saturated overland flow, soil retains a degree of moisture after a rainfall. This residual water moisture affects the soils infiltration capacity, during the next rainfall event, the infiltration capacity will cause the soil to be saturated at a different rate. The higher the level of antecedent soil moisture, the more quickly the soil becomes saturated, once the soil is saturated, runoff occurs. After water infiltrates the soil on a portion of a hill, the water may flow laterally through the soil. This is called subsurface return flow or throughflow, any remaining surface water eventually flows into a receiving water body such as a river, lake, estuary or ocean. Urbanization increases surface runoff by creating more impervious surfaces such as pavement and it is instead forced directly into streams or storm water runoff drains, where erosion and siltation can be major problems, even when flooding is not
18.
Environmental persistent pharmaceutical pollutant
–
The occurring problems from EPPPs are in parallel explained under environmental impact of pharmaceuticals and personal care products. The European Union summarizes pharmaceutical residues with the potential of contamination of water, with exception for downstream sewage treatment plants, the concentration of pharmaceuticals in water is probably extremely low. However, the effect that the exposure to environmental pharmaceuticals chemicals adds to the effects of other chemicals in the cocktail is still not studied. The different chemicals might be potentiating synergistic effects, an extremely sensitive group in this respect are foetuses. EPPPs are already found in all over the world. g. Oestrogen-like chemicals, development of resistant to antibiotics, as is found in India. In Sweden, the industry together with universities and health sector has developed a method for environmental risk assessment. Environmental risk refers to the risk of toxicity to the aquatic environment and it is based on the ratio between predicted environmental concentration of the substance and the highest concentration of the substance that does not have a harmful effect in the environment. Environmental hazard expresses the inherent environmentally damaging characteristics of the substance in terms of persistence, bioaccumulation, the toxicity tests used are acute toxicity of fish, acute toxicity of Daphnia sp. and growth inhibition test of algae. Most medications on the Swedish market are now classified and this gives the health care possibilities to make better choices when prescribing medicines. Concentrations in surface waters, groundwater and partially treated water are typically less than 0.1 µg/l, unused pharmaceuticals reach the environment either via household wastewater or via urban solid garbage handling. Manufacturing plants producing the active substances might unintentionally release pharmaceuticals into the environment, due to improved measurement methods pharmaceuticals may be detected today in concentrations that probably have been present already for decades but could not be measured before. Some pharmaceuticals are degraded to various extents in sewage treatment plants, active residues of pharmaceuticals have been detected in surface water, and they may persist in the environment for long periods of time. EPPPs from treated sewage sludge used as fertilizer are absorbed by soya, there are various pathways how pharmaceutical substances may enter drinking water. Predominantly, drinking water procurement comes from drinking water reservoirs, groundwater, if treated waste water is discharged in catchments with drinking water procurement the not eliminated pharmaceutical substances may be detected in the drinking water. The Netherlands for example gain 37% of their water from surface water, mainly from bank filtration at Rhine. Here certain attention is paid to pharmaceutical residues, in German drinking water catchments and rivers EPPPs have been detected already, especially radiocontrast agents. Moreover, pharmaceutical residues here partly have their origin in agriculture, besides the radiocontrast agents especially the painkiller diclofenac showed relevant concentrations
19.
Meltwater
–
Meltwater is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found in the zone of glaciers, where the rate of snow cover is reducing. Meltwater can be produced during volcanic eruptions, in a way in which the more dangerous lahars form. When meltwater pools on the rather than flowing, it forms melt ponds. As the weather gets colder meltwater will often re-freeze, Meltwater can collect or melt under the ices surface. These pools of water, known as subglacial lakes can form due to geothermal heat, Meltwater provides drinking water for a large proportion of the worlds population, as well as providing water for irrigation and hydroelectric plants. Some cities around the world have large lakes that collect snow melt to supplement water supply, cities that source water from meltwater include Melbourne, Canberra, Los Angeles, Las Vegas amongst others. Glacial meltwater comes from glaciers that have receded over time, often, there will be rivers flowing through glaciers into lakes. These brilliantly blue lakes get their color from rock flour, sediment that has been transported through the rivers to the lakes and this sediment comes from rocks grinding together underneath the glacier. The fine powder is suspended in the water and absorbs and scatters varying colors of sunlight. Meltwater also acts as a lubricant in the sliding of glaciers. Using GPS measurements to study ice flow has revealed that movement is greatest in summer when the meltwater levels are highest. Meltwater can be an indication of abrupt climate change and it can also destabilize glacial lakes leading to sudden floods, and destabilize snowpack causing avalanches. Dammed glacial meltwater from a lake that is released suddenly can result in the floods. Historically Meltwater pulse 1A was a prominent feature of the last deglaciation, extreme Ice Survey Groundwater Moulin Snowmelt Surface water June 4,2007, BBC, UN warning over global ice loss United Nations Environment Program, Global Outlook for Ice and Snow
20.
Natural resource
–
Natural resources are resources that exist without actions of humankind. This includes all valued characteristics such as magnetic, gravitational, on earth it includes, sunlight, atmosphere, water, land along with all vegetation and animal life that naturally subsists upon or within the heretofore identified characteristics and substances. Particular areas such as the rainforest in Fatu-Hiva are often characterized by the biodiversity and geodiversity existent in their ecosystems, Natural resources may be further classified in different ways. Natural resources are materials and components that can be found within the environment, every man-made product is composed of natural resources. Some natural resources such as sunlight and air can be found everywhere, however, most resources only occur in small sporadic areas, and are referred to as localised resources. There are very few resources that are considered inexhaustible – these are solar radiation, geothermal energy, the vast majority of resources are theoretically exhaustible, which means they have a finite quantity and can be depleted if managed improperly. There are various methods of categorizing natural resources, these include source of origin, stage of development, fossil fuels such as coal and petroleum are also included in this category because they are formed from decayed organic matter. Abiotic – Abiotic resources are those that come from non-living, non-organic material, examples of abiotic resources include land, fresh water, air and heavy metals including ores such as gold, iron, copper, silver, etc. For example, petroleum occurs with sedimentary rocks in various regions, Actual resources — Actual resources are those that have been surveyed, their quantity and quality determined and are being used in present times. The development of a resource, such as wood processing depends upon the technology available. Reserve resources — The part of a resource which can be developed profitably in the future is called a reserve resource. Stock resources — Stock resources are those that have been surveyed, renewability is a very popular topic and many natural resources can be categorized as either renewable or non-renewable, Renewable resources — Renewable resources can be replenished naturally. Some of these resources, like sunlight, air, wind, water, etc. are continuously available, though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over-use. Non-renewable resources – Non-renewable resources either form slowly or do not naturally form in the environment, minerals are the most common resource included in this category. Some resources actually naturally deplete in amount without human interference, the most notable of these being radio-active elements such as uranium, of these, the metallic minerals can be re-used by recycling them, but coal and petroleum cannot be recycled. Once they are used they take millions of years to replenish. Resource extraction involves any activity that withdraws resources from nature and this can range in scale from the traditional use of preindustrial societies, to global industry. Extractive industries are, along with agriculture, the basis of the sector of the economy
21.
Atmosphere of Earth
–
The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earths gravity. The atmosphere of Earth protects life on Earth by absorbing solar radiation, warming the surface through heat retention. By volume, dry air contains 78. 09% nitrogen,20. 95% oxygen,0. 93% argon,0. 04% carbon dioxide, and small amounts of other gases. Air also contains an amount of water vapor, on average around 1% at sea level. The atmosphere has a mass of about 5. 15×1018 kg, the atmosphere becomes thinner and thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at 100 km, or 1. 57% of Earths radius, is used as the border between the atmosphere and outer space. Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km, several layers can be distinguished in the atmosphere, based on characteristics such as temperature and composition. The study of Earths atmosphere and its processes is called atmospheric science, early pioneers in the field include Léon Teisserenc de Bort and Richard Assmann. The three major constituents of air, and therefore of Earths atmosphere, are nitrogen, oxygen, water vapor accounts for roughly 0. 25% of the atmosphere by mass. The remaining gases are often referred to as gases, among which are the greenhouse gases, principally carbon dioxide, methane, nitrous oxide. Filtered air includes trace amounts of other chemical compounds. Various industrial pollutants also may be present as gases or aerosols, such as chlorine, fluorine compounds, sulfur compounds such as hydrogen sulfide and sulfur dioxide may be derived from natural sources or from industrial air pollution. In general, air pressure and density decrease with altitude in the atmosphere, however, temperature has a more complicated profile with altitude, and may remain relatively constant or even increase with altitude in some regions. In this way, Earths atmosphere can be divided into five main layers, excluding the exosphere, Earth has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere. It extends from the exobase, which is located at the top of the thermosphere at an altitude of about 700 km above sea level, to about 10,000 km where it merges into the solar wind. This layer is composed of extremely low densities of hydrogen, helium and several heavier molecules including nitrogen, oxygen. The atoms and molecules are so far apart that they can travel hundreds of kilometers without colliding with one another, thus, the exosphere no longer behaves like a gas, and the particles constantly escape into space. These free-moving particles follow ballistic trajectories and may migrate in and out of the magnetosphere or the solar wind, the exosphere is located too far above Earth for any meteorological phenomena to be possible
22.
Air pollution
–
Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earths atmosphere. It may cause diseases, allergies or death in humans, it may cause harm to other living organisms such as animals and food crops. Human activity and natural processes can both generate air pollution, indoor air pollution and poor urban air quality are listed as two of the worlds worst toxic pollution problems in the 2008 Blacksmith Institute Worlds Worst Polluted Places report. According to the 2014 WHO report, air pollution in 2012 caused the deaths of around 7 million people worldwide, an air pollutant is a substance in the air that can have adverse effects on humans and the ecosystem. The substance can be particles, liquid droplets, or gases. A pollutant can be of natural origin or man-made, pollutants are classified as primary or secondary. Primary pollutants are usually produced from a process, such as ash from a volcanic eruption, other examples include carbon monoxide gas from motor vehicle exhaust, or the sulfur dioxide released from factories. Secondary pollutants are not emitted directly, rather, they form in the air when primary pollutants react or interact. Ground level ozone is a prominent example of a secondary pollutant, some pollutants may be both primary and secondary, they are both emitted directly and formed from other primary pollutants. Substances emitted into the atmosphere by human activity include, Carbon dioxide - Debate continues over whether carbon dioxide should be classified as an atmospheric pollutant, because of its role as a greenhouse gas it has been described as the leading pollutant and the worst climate pollution. Against this it is argued that carbon dioxide is a component of the atmosphere, essential for plant life. This question of terminology has practical effects, for example as determining whether the U. S. Clean Air Act is deemed to regulate CO2 emissions, CO2 increase in earths atmosphere has been accelerating. Sulfur oxides - particularly sulfur dioxide, a compound with the formula SO2. SO2 is produced by volcanoes and in industrial processes. Coal and petroleum often contain sulfur compounds, and their combustion generates sulfur dioxide, further oxidation of SO2, usually in the presence of a catalyst such as NO2, forms H2SO4, and thus acid rain. This is one of the causes for concern over the impact of the use of these fuels as power sources. Nitrogen oxides - Nitrogen oxides, particularly nitrogen dioxide, are expelled from high temperature combustion and they can be seen as a brown haze dome above or a plume downwind of cities. Nitrogen dioxide is a compound with the formula NO2
23.
National Ambient Air Quality Standards
–
Secondary standards are designed to protect public welfare from any known or anticipated adverse effects of a pollutant. A district meeting a standard is known as an attainment area for that standard. The standards are listed in 40 C. F. R, ^a Each standard has its own criteria for how many times it may be exceeded, in some cases using a three-year average. ^b As of June 15,2005, the 1-hour ozone standard no longer applies to areas designated with respect to the 8-hour ozone standard. Source, USEPA An air quality control region is an area, designated by the federal government, where communities share a common air pollution problem
24.
Indoor air quality
–
Indoor air quality is a term which refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. IAQ can be affected by gases, particulates, microbial contaminants, source control, filtration and the use of ventilation to dilute contaminants are the primary methods for improving indoor air quality in most buildings. Residential units can further improve air quality by routine cleaning of carpets. Determination of IAQ involves the collection of air samples, monitoring human exposure to pollutants, collection of samples on building surfaces, IAQ is part of indoor environmental quality, which includes IAQ as well as other physical and psychological aspects of life indoors. Indoor air pollution in developing nations is a health hazard. A major source of air pollution in developing countries is the burning of biomass for heating and cooking. The resulting exposure to high levels of particulate matter resulted in between 1.5 million and 2 million deaths in 2000, second-hand smoke is tobacco smoke which affects other people other than the active smoker. The only certain method to improve air quality as regards second-hand smoke is the implementation of comprehensive smoke-free laws. Radon is an invisible, radioactive gas that results from the radioactive decay of radium. Radon is probably the most pervasive serious hazard for air in the United States and Europe. There are relatively simple test kits for do-it-yourself radon gas testing, radon gas enters buildings as a soil gas and is a heavy gas and thus will tend to accumulate at the lowest level. Radon may also be introduced into a building through drinking water particularly from bathroom showers, the half life for radon is 3.8 days, indicating that once the source is removed, the hazard will be greatly reduced within a few weeks. Radon mitigation methods include sealing concrete slab floors, basement foundations, water drainage systems and they are usually cost effective and can greatly reduce or even eliminate the contamination and the associated health risks. Mold is always associated with moisture, and its growth can be inhibited by keeping humidity levels below 50%, in areas where cellulosic materials become moist and fail to dry within 48 hours, mold mildew can propagate and release allergenic spores into the air. In many cases, if materials have failed to dry out several days after the suspected water event, through a mold investigation, which may include destructive inspection, one should be able to determine the presence or absence of mold. In a situation there is visible mold and the indoor air quality may have been compromised. There are some varieties of mold that contain toxic compounds, however, exposure to hazardous levels of mycotoxin via inhalation is not possible in most cases, as toxins are produced by the fungal body and are not at significant levels in the released spores. The primary hazard of mold growth, as it relates to air quality
25.
Indoor air pollution in developing nations
–
Indoor air pollution in developing nations is a significant form of indoor air pollution that is little known to those in the developed world. Three billion people in developing nations across the globe rely on biomass, in the form of wood, charcoal, dung, and crop residue, as their domestic cooking fuel. Because much of the cooking is carried out indoors in environments that lack proper ventilation, millions of people, globally,4.3 million deaths were attributed to exposure to IAP in developing countries in 2012, almost all in low and middle income countries. The South East Asian and Western Pacific regions bear most of the burden with 1.69 and 1.62 million deaths, respectively. Almost 600,000 deaths occur in Africa,200,000 in the Eastern Mediterranean region,99,000 in Europe and 81,000 in the Americas, the remaining 19,000 deaths occur in high income countries. Even though the rate of dependence on biomass fuel is declining and this is due to the poor combustion efficiency of the combustion devices and the elevated nature of the emissions. In addition, they are released directly into living areas. In a typical solid fuel stove, about 6–20% of the fuel is converted into toxic emissions. The exact quantity and relative composition is determined by such as the fuel type and moisture content, stove type. Indoor PM2.5 exposure levels have been reported to be in the range of hundreds to thousands of micrograms per cubic meter. Similarly, CO exposure levels have been measured to be as high as hundreds to greater than 1000 milligrams per cubic meter. Rural Kenya has been the site of various applied research projects to determine the intensity of emissions that occur from use of biomass fuels, particularly wood, dung. Smoke is the result of the combustion of solid fuel which women and children are exposed to up to seven hours each day in closed environments. These emissions vary from day to day, season to season, exposure in poor homes far exceeds accepted safety levels by as much as one hundred times over. Because many Kenyan women utilize a three-stone fire, the worst offender, one kilogram of burning wood produces tiny particles of soot which can clog, the smoke also contains various poisonous gases such as aldehydes, benzene, and carbon monoxide. Exposure to IAP from combustion of solid fuels has been implicated, with varying degrees of evidence, acute lower respiratory infections and chronic obstructive pulmonary disease are the leading causes of disease and death from exposure to smoke. Cataracts and blindness, lung cancer, tuberculosis, premature births and this time could be spent in more productive ways such as attending school or income production. The use of biomass coupled with inefficient cooking apparatus leads to a web of social and environmental concerns which directly links to the United Nations Millennium Development Goals, for example, some improved stove designs in Kenya significantly reduced particulate emissions but produced higher CO2 and SO2 emissions
26.
Air quality law
–
Air quality laws govern the emission of air pollutants into the atmosphere. A specialized subset of air quality laws regulate the quality of air inside buildings, Air quality laws are often designed specifically to protect human health by limiting or eliminating airborne pollutant concentrations. Regulatory efforts include identifying and categorizing air pollutants, setting limits on acceptable emissions levels, Air quality regulation must identify the substances and energies which qualify as pollution for purposes of further control. While specific labels vary from jurisdiction to jurisdiction, there is consensus among many governments regarding what constitutes air pollution. For example, the United States Clean Air Act identifies ozone, particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, EPA has also identified over 180 compounds it has classified as hazardous pollutants requiring strict control. Other compounds have been identified as air pollutants due to their impact on the environment. A broader conception of air pollution may also incorporate noise, light, the United States has recently seen controversy over whether carbon dioxide and other greenhouse gases should be classified as air pollutants. Air quality standards are legal standards or requirements governing concentrations of air pollutants in breathed air and it also generally requires periodic or continuous monitoring of air quality. Another set of standards, for air in employment settings, is administered by the U. S. A distinction may be made mandatory and aspirational air quality standards. For example, U. S. state governments must work toward achieving NAAQS, on the other hand, employers may be required immediately to rectify any violation of OSHA workplace air quality standards. Emission standards are the legal requirements governing air pollutants released into the atmosphere, emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to air quality standards and to protect human health. Numerous methods exist for determining appropriate emissions standards, and different regulatory approaches may be taken depending on the source, industry, specific limits may be set by reference to and within the confines of more general air quality standards. Specific sources may be regulated by means of performance standards, meaning numerical limits on the emission of a pollutant from that source category. Regulators may also mandate the adoption and use of specific technologies, often with reference to feasibility, availability. All of these methods may be modified by incorporating emissions averaging, market mechanisms such as emissions trading, for example, all of these approaches are used in the United States. The United States Environmental Protection Agency, formerly the standard refrigerant in automobile air conditioning systems and its manufacture was prohibited as part of a suite of restrictions adopted internationally in the Montreal Protocol to the Vienna Convention for the Protection of the Ozone Layer
27.
Clean Air Act (United States)
–
The Clean Air Act is a United States federal law designed to control air pollution on a national level. It is one of the United States first and most influential environmental laws. As with many other major U. S. federal environmental statutes, it is administered by the U. S. Environmental Protection Agency, in coordination with state, local and its implementing regulations are codified at 40 C. F. R. The 1955 Air Pollution Control Act was the first U. S federal legislation that pertained to air pollution, the first federal legislation to actually pertain to controlling air pollution was the Clean Air Act of 1963. The 1963 act accomplished this by establishing a program within the U. S. Public Health Service and authorizing research into techniques for monitoring and controlling air pollution, the 1967 act also authorized expanded studies of air pollutant emission inventories, ambient monitoring techniques, and control techniques. Major amendments to the law, requiring regulatory controls for air pollution, the 1970 amendments greatly expanded the federal mandate, requiring comprehensive federal and state regulations for both stationary pollution sources and mobile sources. It also significantly expanded federal enforcement, the 1990 amendments addressed acid rain, ozone depletion, and toxic air pollution, established a national permits program for stationary sources, and increased enforcement authority. Reviewing his tenure as EPA Administrator under President George H. Bush, the Clean Air Act was the first major environmental law in the United States to include a provision for citizen suits. Numerous state and local governments have enacted legislation, either implementing federal programs or filling in locally important gaps in federal programs. This section of the act declares that protecting and enhancing the nations air quality promotes public health, the law encourages prevention of regional air pollution and control programs. It also provides technical and financial assistance for air pollution prevention at both state and local governments, additional subchapters cover of cooperation, research, investigation, training and other activities. Grants for air pollution planning and control programs, and interstate air quality agencies, the act mandates air quality control regions, designated as attainment vs non-attainment. Non-attainment areas do not meet standards for primary or secondary ambient air quality. Attainment areas meet these standards, while unclassifiable areas cannot be classified on the basis of the information that is available, Air quality criteria, national primary and secondary ambient air quality standards, state implementation plans and performance standards for new stationary sources are also covered in Part A. The list of air pollutants established by the act includes acetaldehyde, benzene, chloroform, phenols. The list also includes mineral fiber emissions from manufacturing or processing glass, the list periodically can be modified. The remaining subchapters cover smokestack heights, state plan adequacy, and estimating emissions of carbon monoxide, volatile organic compounds, measures to prevent unemployment or other economic disruption include using local coal or coal derivatives to comply with implementation requirements
28.
Ozone depletion
–
The latter phenomenon is referred to as the ozone hole. In addition to these well-known stratospheric phenomena, there are also springtime polar tropospheric ozone depletion events, the details of polar ozone hole formation differ from that of mid-latitude thinning but the most important process in both is catalytic destruction of ozone by atomic halogens. The main source of these atoms in the stratosphere is photodissociation of man-made halocarbon refrigerants, solvents, propellants. These compounds are transported into the stratosphere by winds after being emitted at the surface, both types of ozone depletion were observed to increase as emissions of halocarbons increased. CFCs and other substances are referred to as ozone-depleting substances. Three forms of oxygen are involved in the cycle, oxygen atoms, oxygen gas. Ozone is formed in the stratosphere when oxygen molecules photodissociate after intaking an ultraviolet photon whose wavelength is shorter than 240 nm and this converts a single O2 into two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2 molecules to create two O3 molecules and these ozone molecules absorb ultraviolet light between 310 and 200 nm, following which ozone splits into a molecule of O2 and an oxygen atom. The oxygen atom then joins up with a molecule to regenerate ozone. This is a process that terminates when an oxygen atom recombines with an ozone molecule to make two O2 molecules. 2 O3 →3 O2 The overall amount of ozone in the stratosphere is determined by a balance between production and recombination. Ozone can be destroyed by a number of free radical catalysts, the dot is a common notation to indicate that all of these species have an unpaired electron and are thus extremely reactive. Cl and Br atoms destroy ozone molecules through a variety of catalytic cycles, in the simplest example of such a cycle, a chlorine atom reacts with an ozone molecule, taking an oxygen atom to form chlorine monoxide and leaving an oxygen molecule. The ClO can react with a molecule of ozone, releasing the chlorine atom. More complicated mechanisms have been discovered that lead to destruction in the lower stratosphere as well. On a per atom basis, bromine is more efficient than chlorine at destroying ozone. As a result, both chlorine and bromine contribute significantly to overall ozone depletion, Laboratory studies have shown that fluorine and iodine atoms participate in analogous catalytic cycles. On average, a chlorine atom is able to react with 100,000 ozone molecules before it is removed from the catalytic cycle
29.
Airshed
–
An airshed is a part of the atmosphere that behaves in a coherent way with respect to the dispersion of emissions. It typically forms an analytical or management unit, also, a geographic boundary for air-quality standards. Alternatively - an airshed is an area where local topography. Georgia Basin-Puget Sound International Airshed Strategy
30.
Emissions trading
–
Emissions trading or cap and trade is a government-mandated, market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants. Various countries, states and groups of companies have adopted such trading systems, a central authority allocates or sells a limited number of permits to discharge specific quantities of a specific pollutant per time period. Polluters are required to hold permits in amount equal to their emissions, polluters that want to increase their emissions must buy permits from others willing to sell them. Financial derivatives of permits can also be traded on secondary markets, in theory, polluters who can reduce emissions most cheaply will do so, achieving the emission reduction at the lowest cost to society. Cap and trade is meant to provide the private sector with the flexibility required to reduce emissions while stimulating technological innovation, there are active trading programs in several air pollutants. For greenhouse gases, which climate change, permit units are often called carbon credits. The United States has a market to reduce acid rain. Pollution is the example of a market externality. An externality is an effect of some activity on an entity that is not party to a market related to that activity. Emissions trading is an approach, among others, to address pollution. The overall goal of an emissions trading plan is to minimize the cost of meeting a set emissions target. In an emissions trading system, the government sets a limit on emissions. The government may sell the permits, but in many existing schemes, the baseline is determined by reference to the participants historical emissions. To demonstrate compliance, a participant must hold permits at least equal to the quantity of pollution it actually emitted during the time period, if every participant complies, the total pollution emitted will be at most equal to the sum of individual limits. In effect, the buyer pays a charge for polluting, while the seller gains a reward for having reduced emissions, in many schemes, organizations which do not pollute may also trade permits and financial derivatives of permits. In some schemes, participants can bank allowances to use in future periods, in some schemes, a proportion of all traded permits must be retired periodically, causing a net reduction in emissions over time. Thus, environmental groups may buy and retire permits, driving up the price of the remaining permits according to the law of demand, in most schemes, permit owners can donate permits to a nonprofit entity and receive a tax deduction. Usually, the government lowers the overall limit over time, with an aim towards an emissions reduction target
31.
Energy
–
In physics, energy is the property that must be transferred to an object in order to perform work on – or to heat – the object, and can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton. Mass and energy are closely related, for example, with a sensitive enough scale, one could measure an increase in mass after heating an object. Living organisms require available energy to stay alive, such as the humans get from food. Civilisation gets the energy it needs from energy resources such as fuels, nuclear fuel. The processes of Earths climate and ecosystem are driven by the radiant energy Earth receives from the sun, the total energy of a system can be subdivided and classified in various ways. It may also be convenient to distinguish gravitational energy, thermal energy, several types of energy, electric energy. Many of these overlap, for instance, thermal energy usually consists partly of kinetic. Some types of energy are a mix of both potential and kinetic energy. An example is energy which is the sum of kinetic. Whenever physical scientists discover that a phenomenon appears to violate the law of energy conservation. Heat and work are special cases in that they are not properties of systems, in general we cannot measure how much heat or work are present in an object, but rather only how much energy is transferred among objects in certain ways during the occurrence of a given process. Heat and work are measured as positive or negative depending on which side of the transfer we view them from, the distinctions between different kinds of energy is not always clear-cut. In contrast to the definition, energeia was a qualitative philosophical concept, broad enough to include ideas such as happiness. The modern analog of this property, kinetic energy, differs from vis viva only by a factor of two, in 1807, Thomas Young was possibly the first to use the term energy instead of vis viva, in its modern sense. Gustave-Gaspard Coriolis described kinetic energy in 1829 in its modern sense, the law of conservation of energy was also first postulated in the early 19th century, and applies to any isolated system. It was argued for years whether heat was a physical substance, dubbed the caloric, or merely a physical quantity. In 1845 James Prescott Joule discovered the link between mechanical work and the generation of heat and these developments led to the theory of conservation of energy, formalized largely by William Thomson as the field of thermodynamics
32.
Energy law
–
Energy laws govern the use and taxation of energy, both renewable and non-renewable. These laws are the primary authorities related to energy, in contrast, energy policy refers to the policy and politics of energy. Energy law includes the provision for oil, gasoline. There is an academic interest in international energy law, including continuing legal education seminars, treatises, law reviews. In the same line, there has growing interest on energy-specific issues and their particular relation with international trade. Nigerias government owns the Nigerian National Petroleum Corporation, Energy is big business in Australia. The Australian Petroleum Production and Exploration Association represents 98% of the oil, Canada has an extensive energy law, both through the federation and the provinces, especially Alberta. The Supreme Court of Canada has had issued some Canadian energy case law, Canada and the Quebec province also own extensive hydroelectric dam facilities, which have generated not only power but controversy. European energy law has focused on the legal mechanisms for managing short-term disruptions to the continents energy supply. The aim of project was enhancing of the safety of hydrogen vehicles and harmonizing their licensing. Five nations have created the EurObservER energy consortium, the EU has also created an Energy Community to extend their policies into Southeastern Europe. Germanys renewable energy law mandates the use of energy through its taxes. It promotes the development of energy sources via a system of feed-in tariffs. It regulates the amount of energy generated by the producer and the type of energy source. It also creates an incentive to encourage technological advancements and costs, the results have been startling, on 6 June 2014, more than half of the nations energy used on that date came from solar power. Despite regulatory processes adding more renewable energy to its mix, Germanys electric grid has become more reliable. The German Green Party has opposed nuclear energy, as well as the power of German utilities. There is significant academic interest in German energy law, a chart summarizing German energy legislation is available
33.
World energy resources
–
World energy resources are the estimated maximum capacity for energy production given all available resources on Earth. They can be divided by type into fossil fuel, nuclear fuel, remaining reserves of fossil fuel are estimated as, These are the proven energy reserves, real reserves may be up to a factor 4 larger. Significant uncertainty exists for these numbers, estimating the remaining fossil fuels on the planet depends on a detailed understanding of the Earths crust. In addition to uncertainty in real reserves, there is significant uncertainty in technological and economical factors that impact what percentage of reserves can be recovered gainfully, in general the easiest to reach deposits are the first extracted. Coal is the most abundant and burned fossil fuel, with the Fischer- Tropsch process it is possible to make liquid fuels such as diesel and jet fuel from coal. In the United States, 49% of electricity comes from burning coal. Natural gas is a widely available fossil fuel with estimated 850000 km³ in recoverable reserves, improvements in technology and wide exploration led to a major increase in recoverable natural gas reserves as shale fracking methods were developed. At present usage rates, natural gas could supply most of the energy needs for between 100 and 250 years, depending on increase in consumption over time. Current consensus among the 18 recognized estimates of supply profiles is that the peak of extraction will occur in 2020 at the rate of 93-million barrels per day, current oil consumption is at the rate of 0.18 ZJ per year or 85-mbd. There is growing concern that oil production may be reached in the near future. A2005 French Economics, Industry and Finance Ministry report suggested a scenario that could occur as early as 2013. There are also theories that peak of the oil production may occur in as little as 2–3 years. The ASPO predicts peak year to be in 2010, some other theories present the view that it has already taken place in 2005. World crude oil production according to US EIA data decreased from a peak of 73.720 mbd in 2005 to 73.437 in 2006,72.981 in 2007, and 73.697 in 2008. In a stated goal of increasing oil prices to $75/barrel, which had fallen from a high of $147 to a low of $40, OPEC announced decreasing production by 2.2 mbd beginning 1 January 2009. Political considerations over the security of supplies, environmental concerns related to global warming, the concept of peak oil shows that about half of the available petroleum resources have been produced, and predicts a decrease of production. A government move away from fossil fuels would most likely create economic pressure through carbon emissions, some countries are taking action as a result of the Kyoto Protocol, and further steps in this direction are proposed. Some estimate, assuming current consumption rates, current oil reserves could be depleted by the year 2050
34.
Fossil fuel
–
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms, containing energy originating in ancient photosynthesis. The age of the organisms and their resulting fossil fuels is typically millions of years, Fossil fuels contain high percentages of carbon and include petroleum, coal, and natural gas. Other commonly used derivatives include kerosene and propane, Fossil fuels range from volatile materials with low carbon, hydrogen ratios like methane, to liquids like petroleum, to nonvolatile materials composed of almost pure carbon, like anthracite coal. Methane can be found in hydrocarbon fields either alone, associated with oil, non-fossil sources in 2006 included nuclear 8. 5%, hydroelectric 6. 3%, and others amounting to 0. 9%. World energy consumption was growing about 2. 3% per year, the use of fossil fuels raises serious environmental concerns. The burning of fossil fuels produces around 21.3 billion tonnes of carbon dioxide per year and it is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year. Carbon dioxide is a gas that increases radiative forcing and contributes to global warming. A global movement towards the generation of energy is underway to help reduce global greenhouse gas emissions. Over geological time, this matter, mixed with mud. Despite these heat driven transformations, the energy is still photosynthetic in origin. There is a range of organic, or hydrocarbon, compounds in any given fuel mixture. The specific mixture of hydrocarbons gives a fuel its characteristic properties, such as boiling point, melting point, density, viscosity, some fuels like natural gas, for instance, contain only very low boiling, gaseous components. Others such as gasoline or diesel contain much higher boiling components, terrestrial plants, on the other hand, tend to form coal and methane. Many of the coal fields date to the Carboniferous period of Earths history, terrestrial plants also form type III kerogen, a source of natural gas. Fossil fuels are of importance because they can be burned. The use of coal as a fuel predates recorded history, coal was used to run furnaces for the melting of metal ore. Semi-solid hydrocarbons from seeps were also burned in ancient times, commercial exploitation of petroleum, largely as a replacement for oils from animal sources, for use in oil lamps began in the 19th century. Natural gas, once flared-off as an byproduct of petroleum production, is now considered a very valuable resource
35.
Peak oil
–
Peak oil, an event based on M. King Hubberts theory, is the point in time when the maximum rate of extraction of petroleum is reached, after which it is expected to enter terminal decline. Peak oil theory is based on the rise, peak, fall. It is often confused with oil depletion, however, peak oil is the point of production, while depletion refers to a period of falling reserves. Some observers, such as petroleum industry experts Kenneth S. Predictions vary greatly as to exactly these negative effects would be. Oil production forecasts on which predictions of peak oil are based are made within a range which includes optimistic and pessimistic scenarios. Pessimistic predictions of future oil production made after 2007 stated either that the peak had already occurred, that oil production was on the cusp of the peak, or that it would occur shortly. Hubberts original prediction that US peak oil would be in about 1970 seemed accurate for a time, in addition, Hubberts original predictions for world peak oil production proved premature. The idea that the rate of oil production would peak and irreversibly decline is an old one, in 1919, David White, chief geologist of the United States Geological Survey, wrote of US petroleum. The peak of production will soon be passed, possibly within 3 years, in 1953, Eugene Ayers, a researcher for Gulf Oil, projected that if US ultimate recoverable oil reserves were 100 billion barrels, then production in the US would peak no later than 1960. If ultimate recoverable were to be as high as 200 billion barrels, likewise for the world, he projected a peak somewhere between 1985 and 2000. Ayers made his projections without a mathematical model, King Hubbert used statistical modelling in 1956 to accurately predict that United States oil production would peak between 1965 and 1971. Hubbert used a semi-logistical curved model and he assumed the production rate of a limited resource would follow a roughly symmetrical distribution. Depending on the limits of exploitability and market pressures, the rise or decline of production over time might be sharper or more stable. That model and its variants are now called Hubbert peak theory, they have used to describe and predict the peak and decline of production from regions, countries. The same theory has also applied to other limited-resource production. In a 2006 analysis of Hubbert theory, it was noted that uncertainty in real world oil production amounts, by comparing the fit of various other models, it was found that Hubberts methods yielded the closest fit over all, but that none of the models were very accurate. In 1956 Hubbert himself recommended using a family of possible production curves when predicting a production peak, more recently, the term peak oil was popularized by Colin Campbell and Kjell Aleklett in 2002 when they helped form the Association for the Study of Peak Oil and Gas. In his publications, Hubbert used the peak production rate
36.
Geothermal energy
–
Geothermal energy is heat energy generated and stored in the Earth. Thermal energy is the energy determines the temperature of matter. The geothermal energy of the Earths crust originates from the formation of the planet. The adjective geothermal originates from the Greek roots γη, meaning earth, Earths internal heat is thermal energy generated from radioactive decay and continual heat loss from Earths formation. Temperatures at the boundary may reach over 4000 °C. Rock and water is heated in the crust, sometimes up to 370 °C, from hot springs, geothermal energy has been used for bathing since Paleolithic times and for space heating since ancient Roman times, but it is now better known for electricity generation. Worldwide,11,700 megawatts of power is online in 2013. An additional 28 gigawatts of geothermal heating capacity is installed for district heating, space heating, spas, industrial processes, desalination. Geothermal power is cost-effective, reliable, sustainable, and environmentally friendly, recent technological advances have dramatically expanded the range and size of viable resources, especially for applications such as home heating, opening a potential for widespread exploitation. Geothermal wells release greenhouse gases trapped deep within the earth, as a result, geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. The Earths geothermal resources are more than adequate to supply humanitys energy needs. Drilling and exploration for resources is very expensive. Forecasts for the future of geothermal power depend on assumptions about technology, energy prices, subsidies, plate boundary movement, pilot programs like EWEBs customer opt in Green Power Program show that customers would be willing to pay a little more for a renewable energy source like geothermal. But as a result of government assisted research and industry experience, in 2001, geothermal energy costs between two and ten US cents per kWh. Hot springs have been used for bathing at least since Paleolithic times, the oldest known spa is a stone pool on Chinas Lisan mountain built in the Qin Dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built. In the first century AD, Romans conquered Aquae Sulis, now Bath, Somerset, England, the admission fees for these baths probably represent the first commercial use of geothermal power. The worlds oldest geothermal district heating system in Chaudes-Aigues, France, has been operating since the 14th century, the earliest industrial exploitation began in 1827 with the use of geyser steam to extract boric acid from volcanic mud in Larderello, Italy. In 1892, Americas first district heating system in Boise, Idaho was powered directly by geothermal energy, and was copied in Klamath Falls, Oregon in 1900
37.
Nuclear power
–
Nuclear power is the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity in a nuclear power plant. The term includes nuclear fission, nuclear decay and nuclear fusion, since all electricity supplying technologies use cement, etc. during construction, emissions are yet to be brought to zero. Each result is contrasted with coal and fossil gas at 820 and 490 g CO2 eq/kWh, there is a social debate about nuclear power. Proponents, such as the World Nuclear Association and Environmentalists for Nuclear Energy, contend that nuclear power is a safe, opponents, such as Greenpeace International and NIRS, contend that nuclear power poses many threats to people and the environment. These include the Chernobyl disaster which occurred in 1986, the Fukushima Daiichi nuclear disaster, there have also been some nuclear submarine accidents. Energy production from coal, petroleum, natural gas and hydroelectricity has caused a number of fatalities per unit of energy generated due to air pollution. In 2015, Ten new reactors were connected to the grid, seven reactors were permanently shut down. 441 reactors had a net capacity of 382,855 megawatts of electricity. 67 new nuclear reactors were under construction, Most of the new activity is in China where there is an urgent need to control pollution from coal plants. In October 2016, Watts Bar 2 became the first new United States reactor to enter commercial operation since 1996. The same year, his doctoral student James Chadwick discovered the neutron, further work by Enrico Fermi in the 1930s focused on using slow neutrons to increase the effectiveness of induced radioactivity. Experiments bombarding uranium with neutrons led Fermi to believe he had created a new, transuranic element and they determined that the relatively tiny neutron split the nucleus of the massive uranium atoms into two roughly equal pieces, contradicting Fermi. Numerous scientists, including Leó Szilárd, who was one of the first, recognized that if fission reactions released additional neutrons, a self-sustaining nuclear chain reaction could result. In the United States, where Fermi and Szilárd had both emigrated, this led to the creation of the first man-made reactor, known as Chicago Pile-1, which achieved criticality on December 2,1942. In 1945, the pocketbook The Atomic Age heralded the untapped atomic power in everyday objects and depicted a future where fossil fuels would go unused. One science writer, David Dietz, wrote that instead of filling the gas tank of a car two or three times a week, people travel for a year on a pellet of atomic energy the size of a vitamin pill. The United Kingdom, Canada, and the USSR proceeded over the course of the late 1940s, electricity was generated for the first time by a nuclear reactor on December 20,1951, at the EBR-I experimental station near Arco, Idaho, which initially produced about 100 kW. Work was also researched in the US on nuclear marine propulsion
38.
Solar energy
–
Active solar techniques include the use of photovoltaic systems, concentrated solar power and solar water heating to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light-dispersing properties, the large magnitude of solar energy available makes it a highly appealing source of electricity. The United Nations Development Programme in its 2000 World Energy Assessment found that the potential of solar energy was 1. This is several times larger than the world energy consumption. In 2011, the International Energy Agency said that the development of affordable, inexhaustible, hence the additional costs of the incentives for early deployment should be considered learning investments, they must be wisely spent and need to be widely shared. The Earth receives 174,000 terawatts of incoming solar radiation at the upper atmosphere, approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of light at the Earths surface is mostly spread across the visible. Most of the population live in areas with insolation levels of 150-300 watts/m². Solar radiation is absorbed by the Earths land surface, oceans – which cover about 71% of the globe –, warm air containing evaporated water from the oceans rises, causing atmospheric circulation or convection. When the air reaches an altitude, where the temperature is low, water vapor condenses into clouds. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 °C. By photosynthesis, green plants convert solar energy into stored energy, which produces food, wood. The total solar energy absorbed by Earths atmosphere, oceans and land masses is approximately 3,850,000 exajoules per year, in 2002, this was more energy in one hour than the world used in one year. Photosynthesis captures approximately 3,000 EJ per year in biomass, geography affects solar energy potential because areas that are closer to the equator have a greater amount of solar radiation. However, the use of photovoltaics that can follow the position of the sun can significantly increase the energy potential in areas that are farther from the equator. Time variation effects the potential of energy because during the nighttime there is little solar radiation on the surface of the Earth for solar panels to absorb. This limits the amount of energy that solar panels can absorb in one day, cloud cover can affect the potential of solar panels because clouds block incoming light from the sun and reduce the light available for solar cells. In addition, land availability has an effect on the available solar energy because solar panels can only be set up on land that is otherwise unused
39.
Sunlight
–
Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is filtered through Earths atmosphere, and is obvious as daylight when the Sun is above the horizon, when the direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When it is blocked by clouds or reflects off other objects, the World Meteorological Organization uses the term sunshine duration to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per square meter. Other sources indicate an Average over the earth of 164 Watts per square meter over a 24 hour day. The ultraviolet radiation in sunlight has both positive and negative effects, as it is both a principal source of vitamin D3 and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface. Researchers may record sunlight using a sunshine recorder, pyranometer, or pyrheliometer, to calculate the amount of sunlight reaching the ground, both Earths elliptical orbit and the attenuation by Earths atmosphere have to be taken into account. In this formula dn–3 is used, because in modern times Earths perihelion, the closest approach to the Sun and, therefore, the value of 0.033412 is determined knowing that the ratio between the perihelion squared and the aphelion squared should be approximately 0.935338. The solar illuminance constant, is equal to 128×103 lx, the atmospheric extinction brings the number of lux down to around 100000. The total amount of energy received at ground level from the Sun at the zenith depends on the distance to the Sun and it is about 3. 3% higher than average in January and 3. 3% lower in July. In terms of energy, sunlight at Earths surface is around 52 to 55 percent infrared,42 to 43 percent visible, and 3 to 5 percent ultraviolet. At the top of the atmosphere, sunlight is about 30% more intense, having about 8% ultraviolet, direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux. This is higher than the efficacy of most artificial lighting, which means using sunlight for illumination heats up a less than using most forms of artificial lighting. Multiplying the figure of 1050 watts per square metre by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98000 lux on a surface at sea level. The illumination of a surface will be considerably less than this if the Sun is not very high in the sky. Averaged over a day, the highest amount of sunlight on a horizontal surface occurs in January at the South Pole, dividing the irradiance of 1050 W/m2 by the size of the suns disk in steradians gives an average radiance of 15.4 MW per square metre per steradian. Multiplying this by π gives a limit to the irradiance which can be focused on a surface using mirrors,48.5 MW/m2
40.
Shade (shadow)
–
Shade is the blocking of sunlight by any object, and also the shadow created by that object. Shade also consists of the grey, black, white. It may refer to blocking of sunlight by a roof, a tree, an umbrella, shade is an important issue in temperate and tropical zones for providing cooling and shelter from the sun. Green plants produce shade by absorbing sunlight to invest as energy in photosynthesis to produce sugar and they also actively transpire, producing an additional cooling effect. In gardening terms, there are types of shade, Full sun - more than five hours of direct sun per day. Part shade - two to five hours of sun, or all-day dappled sun. Full shade - less than two hours of sun per day. Under a dense forest canopy, light intensity can be very low, special adaptations produce the shade tolerance that allows plants to survive in the understory. In addition, shade within a canopy can elicit shade avoidance responses whereby plants elongate their shoots in order to light for optimal photosynthesis
41.
Tidal power
–
Tidal power or tidal energy is a form of hydropower that converts the energy obtained from tides into useful forms of power, mainly electricity. Although not yet used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power, historically, tide mills have been used both in Europe and on the Atlantic coast of North America. The incoming water was contained in large ponds, and as the tide went out. The earliest occurrences date from the Middle Ages, or even from Roman times, the process of using falling water and spinning turbines to create electricity was introduced in the U. S. and Europe in the 19th century. The worlds first large-scale tidal power plant was the Rance Tidal Power Station in France and it was the largest tidal power station in terms of output until Sihwa Lake Tidal Power Station opened in South Korea in August,2011. The Sihwa station uses sea wall defense barriers complete with 10 turbines generating 254 MW, Tidal power is taken from the Earths oceanic tides. Tidal forces are periodic variations in gravitational attraction exerted by celestial bodies and these forces create corresponding motions or currents in the worlds oceans. Due to the attraction to the oceans, a bulge in the water level is created. When the sea level is raised, water from the middle of the ocean is forced to move toward the shorelines and this occurrence takes place in an unfailing manner, due to the consistent pattern of the moon’s orbit around the earth. Tidal power is the technology that draws on energy inherent in the orbital characteristics of the Earth–Moon system. Other natural energies exploited by human technology originate directly or indirectly with the Sun, including fuel, conventional hydroelectric, wind, biofuel, wave. A tidal generator converts the energy of tidal flows into electricity, greater tidal variation and higher tidal current velocities can dramatically increase the potential of a site for tidal electricity generation. This loss of energy has caused the rotation of the Earth to slow in the 4.5 billion years since its formation. During the last 620 million years the period of rotation of the earth has increased from 21.9 hours to 24 hours, while tidal power will take additional energy from the system, the effect is negligible and would only be noticed over millions of years. Some tidal generators can be built into the structures of existing bridges or are entirely submersed, land constrictions such as straits or inlets can create high velocities at specific sites, which can be captured with the use of turbines. These turbines can be horizontal, vertical, open, or ducted, Tidal barrages make use of the potential energy in the difference in height between high and low tides. When using tidal barrages to generate power, the energy from a tide is seized through strategic placement of specialized dams
42.
Wave power
–
Wave power is the transport of energy by wind waves, and the capture of that energy to do useful work – for example, electricity generation, water desalination, or the pumping of water. A machine able to exploit wave power is known as a wave energy converter. Wave power is distinct from the flux of tidal power. Wave-power generation is not currently a widely employed commercial technology, although there have been attempts to use it since at least 1890, in 2008, the first experimental wave farm was opened in Portugal, at the Aguçadoura Wave Park. Waves are generated by passing over the surface of the sea. As long as the waves propagate slower than the speed just above the waves. Wave height is determined by speed, the duration of time the wind has been blowing, fetch and by the depth. A given wind speed has a practical limit over which time or distance will not produce larger waves. When this limit has been reached the sea is said to be fully developed, in general, larger waves are more powerful but wave power is also determined by wave speed, wavelength, and water density. Oscillatory motion is highest at the surface and diminishes exponentially with depth, however, for standing waves near a reflecting coast, wave energy is also present as pressure oscillations at great depth, producing microseisms. These pressure fluctuations at greater depth are too small to be interesting from the point of view of wave power, the waves propagate on the ocean surface, and the wave energy is also transported horizontally with the group velocity. The mean transport rate of the energy through a vertical plane of unit width. The above formula states that power is proportional to the wave energy period. When the significant wave height is given in metres, and the period in seconds. Example, Consider moderate ocean swells, in water, a few km off a coastline, with a wave height of 3 m. Using the formula to solve for power, we get P ≈0.5 kW m 3 ⋅ s 2 ≈36 kW m, in major storms, the largest waves offshore are about 15 meters high and have a period of about 15 seconds. According to the formula, such waves carry about 1.7 MW of power across each metre of wavefront. An effective wave power device captures as much as possible of the energy flux
43.
Wind power
–
Wind power is the use of air flow through wind turbines to mechanically power generators for electric power. The net effects on the environment are far less problematic than those of power sources. Wind farms consist of individual wind turbines which are connected to the electric power transmission network. Onshore wind is a source of electric power, competitive with or in many places cheaper than coal or gas plants. Offshore wind is steadier and stronger than on land, and offshore farms have less visual impact, small onshore wind farms can feed some energy into the grid or provide electric power to isolated off-grid locations. Wind power gives variable power which is consistent from year to year. It is therefore used in conjunction with other power sources to give a reliable supply. As the proportion of power in a region increases, a need to upgrade the grid. In addition, weather forecasting permits the power network to be readied for the predictable variations in production that occur. As of 2015, Denmark generates 40% of its power from wind. In 2014 global wind power capacity expanded 16% to 369,553 MW, yearly wind energy production is also growing rapidly and has reached around 4% of worldwide electric power usage,11. 4% in the EU. Wind power has been used as long as humans have put sails into the wind, for more than two millennia wind-powered machines have ground grain and pumped water. Wind power was available and not confined to the banks of fast-flowing streams, or later. Wind-powered pumps drained the polders of the Netherlands, and in regions such as the American mid-west or the Australian outback, wind pumps provided water for live stock. The first windmill used for the production of power was built in Scotland in July 1887 by Prof James Blyth of Andersons College. Blyth offered the surplus power to the people of Marykirk for lighting the main street, however. The Brush wind turbine had a rotor 17 metres in diameter and was mounted on an 18 metres tower, although large by todays standards, the machine was only rated at 12 kW. The connected dynamo was used either to charge a bank of batteries or to operate up to 100 incandescent light bulbs, with the development of electric power, wind power found new applications in lighting buildings remote from centrally-generated power
44.
Arable land
–
Arable land is, according to one definition, land capable of being ploughed and used to grow crops. In Britain, it was contrasted with pasturable lands such as heaths which could be used for sheep-rearing. A quite different kind of definition is used by various agencies concerned with agriculture, the abandoned land resulting from shifting cultivation is not included in this category. Data for ‘Arable land’ are not meant to indicate the amount of land that is potentially cultivable, a briefer definition appearing in the Eurostat glossary similarly refers to actual, rather than potential use, land worked regularly, generally under a system of crop rotation. According to Food and Agriculture Organization of the United Nations the worlds Arable land amounted to 1,407 M ha, out of a total 4,924 M ha land used for agriculture, as for year 2013. Agricultural land that is not arable according to the FAO definition above includes, Permanent crop - land that produces crops from woody vegetation, other non-arable land includes land unsuitable for any agricultural use. Although such limitations may preclude cultivation, and some will in some cases preclude any agricultural use, for example, US NRCS statistics indicate that about 59 percent of US non-federal pasture and unforested rangeland is unsuitable for cultivation, yet such land has value for grazing of livestock. Similar examples can be found in many rangeland areas elsewhere, land incapable of being cultivated for production of crops can sometimes be converted to arable land. New arable land makes more food, and can reduce starvation and this outcome also makes a country more self-sufficient and politically independent, because food importation is reduced. This process is extremely expensive. An alternative is the Seawater Greenhouse which desalinates water through evaporation and condensation using solar energy as the energy input. This technology is optimized to grow crops on land close to the sea. The people covered the islands with a layer of seaweed. Israel, The construction of desalination plants along Israels coast allowed agriculture in areas that were formerly desert. The desalination plants, which remove the salt from water, have created a new source of water for farming, drinking. Slash and burn agriculture uses nutrients in wood ash, but these expire within a few years, terra preta, fertile tropical soils created by adding charcoal. Some examples of fertile land being turned into infertile land are. Rainforest deforestation, The fertile tropical forests are converted into infertile desert land, for example, Madagascars central highland plateau has become virtually totally barren, as a result of slash-and-burn deforestation, an element of shifting cultivation practiced by many natives
