A lake is an area filled with water, localized in a basin, 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, therefore are distinct from lagoons, are larger and deeper than ponds, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which are flowing. Most lakes streams. Natural lakes are found in mountainous areas, rift zones, areas with ongoing glaciation. Other lakes are found 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. Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic, recreational purposes, or other activities.
The word lake comes from Middle English lake, from Old English lacu, from Proto-Germanic *lakō, from the Proto-Indo-European root *leǵ-. Cognates include Dutch laak, Middle Low German lāke as in: de:Wolfslake, de:Butterlake, German Lache, Icelandic lækur. Related are the English words leak and leach. There is considerable uncertainty about defining the difference between lakes and ponds, no current internationally accepted definition of either term across scientific disciplines or political boundaries exists. For example, limnologists have defined lakes as water bodies which are a larger version of a pond, which can have wave action on the shoreline or where wind-induced turbulence plays a major role in mixing the water column. None of these definitions excludes ponds and all are difficult to measure. For this reason, simple size-based definitions are used to separate ponds and lakes. Definitions for lake range in minimum sizes for a body of water from 2 hectares to 8 hectares. 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, a dry basin most of the time but may become filled under seasonal conditions of heavy rainfall. In common usage, many lakes bear names ending with the word pond, a lesser number of names ending with lake are in quasi-technical fact, ponds. One textbook illustrates this point with the following: "In Newfoundland, for example every lake is called a pond, whereas in Wisconsin every pond is called a lake."One hydrology book proposes to define the term "lake" as a body of water with the following five characteristics: it or fills one or several basins connected by straits has the same water level in all parts it does not have regular intrusion of seawater a considerable portion of the sediment suspended in the water is captured by the basins the area measured at the mean water level exceeds an arbitrarily chosen threshold With the exception of the seawater intrusion criterion, the others have been accepted or elaborated upon by other hydrology publications.
The majority of lakes on Earth are freshwater, most lie in the Northern Hemisphere at higher latitudes. Canada, with a deranged drainage system has an estimated 31,752 lakes larger than 3 square kilometres and an unknown total number of lakes, but is estimated to be at least 2 million. Finland has larger, of which 56,000 are large. Most lakes have at least one natural outflow in the form of a river or stream, which maintain a lake's average level by allowing the drainage of excess water; some lakes do not have a natural outflow and lose water by evaporation or underground seepage or both. They are termed endorheic lakes. Many lakes are artificial and are constructed for hydro-electric power generation, aesthetic purposes, recreational purposes, industrial use, agricultural use or domestic water supply. Evidence of extraterrestrial lakes exists. Globally, lakes are outnumbered by ponds: of an estimated 304 million standing water bodies worldwide, 91% are 1 hectare or less in area. Small lakes are much more numerous than large lakes: in terms of area, one-third of the world's standing water is represented by lakes and ponds of 10 hectares or less.
However, large lakes account for much of the area of standing water with 122 large lakes of 1,000 square kilometres or more representing about 29% of the total global area of standing inland water. Hutchinson in 1957 published a monograph, regarded as a landmark discussion and classification of all major lake types, their origin, morphometric characteristics, distribution; as summarized and discussed by these researchers, Hutchinson presented in it a comprehensive analysis of the origin of lakes and proposed what is a accepted classification of lakes according to their origin. This
Nevada is a state in the Western United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast and Utah to the east. Nevada is the 7th most extensive, the 32nd most populous, but the 9th least densely populated of the U. S. states. Nearly three-quarters of Nevada's people live in Clark County, which contains the Las Vegas–Paradise metropolitan area where three of the state's four largest incorporated cities are located. Nevada's capital, however, is Carson City. Nevada is known as the "Silver State" because of the importance of silver to its history and economy, it is known as the "Battle Born State", because it achieved statehood during the Civil War. Nevada is desert and semi-arid, much of it within the Great Basin. Areas south of the Great Basin are within the Mojave Desert, while Lake Tahoe and the Sierra Nevada lie on the western edge. About 86% of the state's land is managed by various jurisdictions of the U. S. federal government, both civilian and military.
Before European contact, Native Americans of the Paiute and Washoe tribes inhabited the land, now Nevada. The first Europeans to explore the region were Spanish, they called the region Nevada because of the snow. The area formed part of the Viceroyalty of New Spain, became part of Mexico when it gained independence in 1821; the United States annexed the area in 1848 after its victory in the Mexican–American War, it was incorporated as part of Utah Territory in 1850. The discovery of silver at the Comstock Lode in 1859 led to a population boom that became an impetus to the creation of Nevada Territory out of western Utah Territory in 1861. Nevada became the 36th state on October 31, 1864, as the second of two states added to the Union during the Civil War. Nevada has a reputation for its libertarian laws. In 1940, with a population of just over 110,000 people, Nevada was by far the least-populated state, with less than half the population of the next least-populated state. However, legalized gambling and lenient marriage and divorce laws transformed Nevada into a major tourist destination in the 20th century.
Nevada is the only U. S. state where prostitution is legal, though it is illegal in Clark County, Washoe County and Carson City. The tourism industry remains Nevada's largest employer, with mining continuing as a substantial sector of the economy: Nevada is the fourth-largest producer of gold in the world; the name "Nevada" comes from meaning "snow-covered", after the Sierra Nevada. Most Nevadans pronounce the second syllable of their state name using the TRAP vowel. Many from outside the Western United States pronounce it with the PALM vowel. Although the latter pronunciation is closer to the Spanish pronunciation, it is not the pronunciation preferred by most Nevadans. State Assemblyman Harry Mortenson proposed a bill to recognize the alternate pronunciation of Nevada, though the bill was not supported by most legislators and never received a vote; the Nevadan pronunciation is the de facto official one, since it is the one used by the state legislature. At one time, the state's official tourism organization, TravelNevada, stylized the name of the state as "Nevăda", with a breve mark over the a indicating the locally preferred pronunciation, available as a license plate design.
Nevada is entirely within the Basin and Range Province, is broken up by many north-south mountain ranges. Most of these ranges have endorheic valleys between them, which belies the image portrayed by the term Great Basin. Much of the northern part of the state is within the Great Basin, a mild desert that experiences hot temperatures in the summer and cold temperatures in the winter. Moisture from the Arizona Monsoon will cause summer thunderstorms; the state's highest recorded temperature was 125 °F in Laughlin on June 29, 1994. The coldest recorded temperature was −52 °F set in San Jacinto in 1972, in the northeastern portion of the state; the Humboldt River crosses the state from east to west across the northern part of the state, draining into the Humboldt Sink near Lovelock. Several rivers drain from the Sierra Nevada eastward, including the Walker and Carson rivers. All of these rivers are endorheic basins, ending in Walker Lake, Pyramid Lake, the Carson Sink, respectively. However, not all of Nevada is within the Great Basin.
Tributaries of the Snake River drain the far north, while the Colorado River, which forms much of the boundary with Arizona, drains much of southern Nevada. The mountain ranges, some of which have peaks above 13,000 feet, harbor lush forests high above desert plains, creating sky islands for endemic species; the valleys are no lower in elevation than 3,000 feet, while some in central Nevada are above 6,000 feet. The southern third of the state, where the Las Vegas area is situated, is within the Mojave Desert; the area is closer to the Arizona Monsoon in the summer. The terrain is lower below 4,000 feet, creating conditions for hot summer days and cool to chilly winter nights. Nevada and California have by far the longest diagonal line as a state boundary at just over 400 miles; this line begins in Lake Tahoe nearly