Democracy is a system of government where the citizens exercise power by voting. In a direct democracy, the citizens as a whole form a governing body and vote directly on each issue. In a representative democracy the citizens elect representatives from among themselves; these representatives meet to form a governing body, such as a legislature. In a constitutional democracy the powers of the majority are exercised within the framework of a representative democracy, but the constitution limits the majority and protects the minority through the enjoyment by all of certain individual rights, e.g. freedom of speech, or freedom of association. "Rule of the majority" is sometimes referred to as democracy. Democracy is a system of processing conflicts in which outcomes depend on what participants do, but no single force controls what occurs and its outcomes; the uncertainty of outcomes is inherent in democracy, which makes all forces struggle for the realization of their interests, being the devolution of power from a group of people to a set of rules.
Western democracy, as distinct from that which existed in pre-modern societies, is considered to have originated in city-states such as Classical Athens and the Roman Republic, where various schemes and degrees of enfranchisement of the free male population were observed before the form disappeared in the West at the beginning of late antiquity. The English word dates back to the 16th century, from the older Middle French and Middle Latin equivalents. According to American political scientist Larry Diamond, democracy consists of four key elements: a political system for choosing and replacing the government through free and fair elections. Todd Landman draws our attention to the fact that democracy and human rights are two different concepts and that "there must be greater specificity in the conceptualisation and operationalization of democracy and human rights"; the term appeared in the 5th century BC to denote the political systems existing in Greek city-states, notably Athens, to mean "rule of the people", in contrast to aristocracy, meaning "rule of an elite".
While theoretically these definitions are in opposition, in practice the distinction has been blurred historically. The political system of Classical Athens, for example, granted democratic citizenship to free men and excluded slaves and women from political participation. In all democratic governments throughout ancient and modern history, democratic citizenship consisted of an elite class, until full enfranchisement was won for all adult citizens in most modern democracies through the suffrage movements of the 19th and 20th centuries. Democracy contrasts with forms of government where power is either held by an individual, as in an absolute monarchy, or where power is held by a small number of individuals, as in an oligarchy; these oppositions, inherited from Greek philosophy, are now ambiguous because contemporary governments have mixed democratic and monarchic elements. Karl Popper defined democracy in contrast to dictatorship or tyranny, thus focusing on opportunities for the people to control their leaders and to oust them without the need for a revolution.
No consensus exists on how to define democracy, but legal equality, political freedom and rule of law have been identified as important characteristics. These principles are reflected in all eligible citizens being equal before the law and having equal access to legislative processes. For example, in a representative democracy, every vote has equal weight, no unreasonable restrictions can apply to anyone seeking to become a representative, the freedom of its eligible citizens is secured by legitimised rights and liberties which are protected by a constitution. Other uses of "democracy" include that of direct democracy. One theory holds that democracy requires three fundamental principles: upward control, political equality, social norms by which individuals and institutions only consider acceptable acts that reflect the first two principles of upward control and political equality; the term "democracy" is sometimes used as shorthand for liberal democracy, a variant of representative democracy that may include elements such as political pluralism.
Roger Scruton argues that democracy alone cannot provide personal and political freedom unless the institutions of civil society are present. In some countries, notably in the United Kingdom which originated the Westminster system, the dominant principle is that of parliamentary sovereignty, while maintaining judicial independence. In the United States, separation of powers is cited as a central attribute. In India, parliamentary sovereignty is subject to the Constitution of India which includes judicial review. Though the term "democracy" is used in the context of a political state, the principles are applicable to private organisations. Majority rule is listed as a characteristic of democracy. Hence, democracy allows for political minorities to be oppressed by the "tyranny of the majority" in the absence of legal protections of individual or group rights. An essential part of an "ideal" representative democracy is competitive elections that are substantively and procedurally "fair," i.e. just and equitable
President of the United States
The president of the United States is the head of state and head of government of the United States of America. The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces. In contemporary times, the president is looked upon as one of the world's most powerful political figures as the leader of the only remaining global superpower; the role includes responsibility for the world's most expensive military, which has the second largest nuclear arsenal. The president leads the nation with the largest economy by nominal GDP; the president possesses international hard and soft power. Article II of the Constitution establishes the executive branch of the federal government, it vests the executive power of the United States in the president. The power includes the execution and enforcement of federal law, alongside the responsibility of appointing federal executive, diplomatic and judicial officers, concluding treaties with foreign powers with the advice and consent of the Senate.
The president is further empowered to grant federal pardons and reprieves, to convene and adjourn either or both houses of Congress under extraordinary circumstances. The president directs the foreign and domestic policies of the United States, takes an active role in promoting his policy priorities to members of Congress. In addition, as part of the system of checks and balances, Article I, Section 7 of the Constitution gives the president the power to sign or veto federal legislation; the power of the presidency has grown since its formation, as has the power of the federal government as a whole. Through the Electoral College, registered voters indirectly elect the president and vice president to a four-year term; this is the only federal election in the United States, not decided by popular vote. Nine vice presidents became president by virtue of a president's intra-term resignation. Article II, Section 1, Clause 5 sets three qualifications for holding the presidency: natural-born U. S. citizenship.
The Twenty-second Amendment precludes any person from being elected president to a third term. In all, 44 individuals have served 45 presidencies spanning 57 full four-year terms. Grover Cleveland served two non-consecutive terms, so he is counted twice, as both the 22nd and 24th president. Donald Trump of New York is the current president of the United States, he assumed office on January 20, 2017. In July 1776, during the American Revolutionary War, the Thirteen Colonies, acting jointly through the Second Continental Congress, declared themselves to be 13 independent sovereign states, no longer under British rule. Recognizing the necessity of coordinating their efforts against the British, the Continental Congress began the process of drafting a constitution that would bind the states together. There were long debates on a number of issues, including representation and voting, the exact powers to be given the central government. Congress finished work on the Articles of Confederation to establish a perpetual union between the states in November 1777 and sent it to the states for ratification.
Under the Articles, which took effect on March 1, 1781, the Congress of the Confederation was a central political authority without any legislative power. It could make its own resolutions and regulations, but not any laws, could not impose any taxes or enforce local commercial regulations upon its citizens; this institutional design reflected how Americans believed the deposed British system of Crown and Parliament ought to have functioned with respect to the royal dominion: a superintending body for matters that concerned the entire empire. The states were out from under any monarchy and assigned some royal prerogatives to Congress; the members of Congress elected a President of the United States in Congress Assembled to preside over its deliberation as a neutral discussion moderator. Unrelated to and quite dissimilar from the office of President of the United States, it was a ceremonial position without much influence. In 1783, the Treaty of Paris secured independence for each of the former colonies.
With peace at hand, the states each turned toward their own internal affairs. By 1786, Americans found their continental borders besieged and weak and their respective economies in crises as neighboring states agitated trade rivalries with one another, they witnessed their hard currency pouring into foreign markets to pay for imports, their Mediterranean commerce preyed upon by North African pirates, their foreign-financed Revolutionary War debts unpaid and accruing interest. Civil and political unrest loomed. Following the successful resolution of commercial and fishing disputes between Virginia and Maryland at the Mount Vernon Conference in 1785, Virginia called for a trade conference between all the states, set for September 1786 in Annapolis, with an aim toward resolving further-reaching interstate commercial antagonisms; when the convention failed for lack of attendance due to suspicions among most of the other states, Alexander Hamilton led the Annapolis delegates in a call for a convention to offer revisions to the Articles, to be held the next spring in Philadelphia.
Prospects for the next convention appeared bleak until James Madison and Edmund Randolph succeeded in securing George Washington's attendance to Philadelphia as a delegate for Virginia. When the Constitutional Convention convened in May 1787, the 12 state delegations in attendance (Rh
Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, more known as Dr. Strangelove, is a 1964 political satire black comedy film that satirizes the Cold War fears of a nuclear conflict between the Soviet Union and the United States; the film was directed, co-written by Stanley Kubrick, stars Peter Sellers, George C. Scott and Slim Pickens. Production took place in the United Kingdom; the film is loosely based on Peter George's thriller novel Red Alert. The story concerns an unhinged United States Air Force general who orders a first strike nuclear attack on the Soviet Union, it follows the President of the United States, his advisors, the Joint Chiefs of Staff, a Royal Air Force officer as they try to recall the bombers to prevent a nuclear apocalypse. It separately follows the crew of one B-52 bomber. In 1989, the United States Library of Congress included Dr. Strangelove in the first group of films selected for preservation in the National Film Registry, it was listed as number three on AFI's 100 Years...100 Laughs list.
United States Air Force Brigadier General Jack D. Ripper is commander of Burpelson Air Force Base, which houses the Strategic Air Command 843rd Bomb Wing, flying B-52 bombers armed with hydrogen bombs; the 843rd Wing is flying on airborne alert, two hours from their targets inside the USSR. General Ripper orders his executive officer, Group Captain Lionel Mandrake of the UK Royal Air Force, to put the base on alert. Ripper issues "Wing Attack Plan R" to the patrolling aircraft, one of, commanded by Major T. J. "King" Kong. All of the aircraft commence an attack flight on the USSR and set their radios to allow communications only through their CRM 114 discriminators, designed to accept only communications preceded by a secret three-letter code known only to General Ripper. Mandrake discovers that no war order has been issued by the Pentagon and he tries to stop Ripper, who locks them both in his office. Ripper tells Mandrake that he believes the Soviets have been using fluoridation of the American water supplies to pollute the "precious bodily fluids" of Americans.
Mandrake realizes. In the War Room at the Pentagon, General Buck Turgidson briefs President Merkin Muffley and other officers about how Plan R enables a senior officer to launch a strike against the Soviets if all superiors have been killed in a first strike on the United States. Turgidson reports that his men are trying every possible three-letter CRM code to issue the stand-down order, but that could take over two days and the planes are due to reach their targets in a couple of hours. Muffley orders the U. S. Army to arrest General Ripper. Turgidson attempts to convince Muffley to let the attack continue, but Muffley refuses to be party to a nuclear first strike. Instead, he brings Soviet ambassador Alexei de Sadeski into the War Room to telephone Soviet Premier Dimitri Kissov on the "hot line". Muffley warns the Premier of the impending attack and offers to reveal the positions of the bombers and targets so that the Soviets can protect themselves. After a heated discussion in Russian with the Premier, the ambassador informs President Muffley that the Soviet Union has created a doomsday machine, which consists of many buried bombs jacketed with "cobalt-thorium G" connected to a computer network set to detonate them automatically should any nuclear attack strike the country.
Within two months after detonation, the cobalt-thorium G would encircle the planet in a radioactive "doomsday shroud", wiping out all human and animal life, rendering the surface of the Earth uninhabitable for about 93 years. The device cannot be dismantled or "untriggered", as it is programmed to explode if any such attempt is made; when the President's wheelchair-bound scientific advisor, the former Nazi German Dr. Strangelove, points out that such a doomsday machine would only be an effective deterrent if everyone knew about it, de Sadeski replies that the Soviet Premier had planned to reveal its existence to the world the following week. Meanwhile, U. S. Army troops arrive at Burpelson, still sealed by Ripper's order, to take over the base after a heated firefight with Air Force security policemen. General Ripper shoots and kills himself, while Mandrake identifies Ripper's CRM code from his desk blotter and relays this code to the Pentagon. Using the recall code, SAC recalls all of the bombers but one.
No one in the War Room knows that a Soviet surface-to-air missile has damaged the fuel tanks of that plane and destroyed its radio equipment, making it impossible to recall this particular plane with the correct recall code. Muffley discloses the plane's target to help the Soviets find it, but its commanding officer, Major Kong, with his fuel dwindling, has selected a nearer target instead; as the plane approaches the new target, the crew is unable to open the damaged bomb bay doors. Kong enters the bomb bay and repairs the broken electrical wiring, whereupon the doors open and the H-bomb is dropped. With Kong straddling it, the bomb detonates over a Soviet ICBM site. Back in the War Room, Dr. Strangelove recommends that the President gather several hundred thousand people to live in deep underground mines where the radiation will not penetrate, he suggests a 10:1 female-to-male ratio for a breeding program to repopulate the Earth once the radiation has subsided. Turgidson, worried that the Soviets will do the same, warns about a "mineshaft gap".
Dr. Strangelove declares he has a plan, but rises from his wheelchair and announces that he can walk again. Soon, the Doomsday Machine kicks into operation, the film ends with a montage of many nuclear explosion
California is a state in the Pacific Region of the United States. With 39.6 million residents, California is the most populous U. S. the third-largest by area. The state capital is Sacramento; the Greater Los Angeles Area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions, with 18.7 million and 9.7 million residents respectively. Los Angeles is California's most populous city, the country's second most populous, after New York City. California has the nation's most populous county, Los Angeles County, its largest county by area, San Bernardino County; the City and County of San Francisco is both the country's second-most densely populated major city after New York City and the fifth-most densely populated county, behind only four of the five New York City boroughs. California's $3.0 trillion economy is larger than that of any other state, larger than those of Texas and Florida combined, the largest sub-national economy in the world. If it were a country, California would be the 5th largest economy in the world, the 36th most populous as of 2017.
The Greater Los Angeles Area and the San Francisco Bay Area are the nation's second- and third-largest urban economies, after the New York metropolitan area. The San Francisco Bay Area PSA had the nation's highest GDP per capita in 2017 among large PSAs, is home to three of the world's ten largest companies by market capitalization and four of the world's ten richest people. California is considered a global trendsetter in popular culture, innovation and politics, it is considered the origin of the American film industry, the hippie counterculture, fast food, the Internet, the personal computer, among others. The San Francisco Bay Area and the Greater Los Angeles Area are seen as global centers of the technology and entertainment industries, respectively. California has a diverse economy: 58% of the state's economy is centered on finance, real estate services and professional, scientific and technical business services. Although it accounts for only 1.5% of the state's economy, California's agriculture industry has the highest output of any U.
S. state. California is bordered by Oregon to the north and Arizona to the east, the Mexican state of Baja California to the south; the state's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east, from the redwood–Douglas fir forests in the northwest to the Mojave Desert in the southeast. The Central Valley, a major agricultural area, dominates the state's center. Although California is well-known for its warm Mediterranean climate, the large size of the state results in climates that vary from moist temperate rainforest in the north to arid desert in the interior, as well as snowy alpine in the mountains. Over time and wildfires have become more pervasive features. What is now California was first settled by various Native Californian tribes before being explored by a number of European expeditions during the 16th and 17th centuries; the Spanish Empire claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its successful war for independence but was ceded to the United States in 1848 after the Mexican–American War.
The western portion of Alta California was organized and admitted as the 31st state on September 9, 1850. The California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom; the word California referred to the Baja California Peninsula of Mexico. The name derived from the mythical island California in the fictional story of Queen Calafia, as recorded in a 1510 work The Adventures of Esplandián by Garci Rodríguez de Montalvo; this work was the fifth in a popular Spanish chivalric romance series that began with Amadis de Gaula. Queen Calafia's kingdom was said to be a remote land rich in gold and pearls, inhabited by beautiful black women who wore gold armor and lived like Amazons, as well as griffins and other strange beasts. In the fictional paradise, the ruler Queen Calafia fought alongside Muslims and her name may have been chosen to echo the title of a Muslim leader, the Caliph. It's possible.
Know ye that at the right hand of the Indies there is an island called California close to that part of the Terrestrial Paradise, inhabited by black women without a single man among them, they lived in the manner of Amazons. They were robust of body with great virtue; the island itself is one of the wildest in the world on account of the craggy rocks. Shortened forms of the state's name include CA, Cal. Calif. and US-CA. Settled by successive waves of arrivals during the last 10,000 years, California was one of the most culturally and linguistically diverse areas in pre-Columbian North America. Various estimates of the native population range from 100,000 to 300,000; the Indigenous peoples of California included more than 70 distinct groups of Native Americans, ranging from large, settled populations living on the coast to groups in the interior. California groups were diverse in their political organization with bands, villages, on the resource-rich coasts, large chiefdoms, such as the Chumash and Salinan.
Trade, intermarriage a
The White House is the official residence and workplace of the President of the United States. It is located at 1600 Pennsylvania Avenue NW in Washington, D. C. and has been the residence of every U. S. President since John Adams in 1800; the term "White House" is used as a metonym for the president and his advisers. The residence was designed by Irish-born architect James Hoban in the neoclassical style. Hoban modelled the building on Leinster House in Dublin, a building which today houses the Oireachtas, the Irish legislature. Construction took place between 1800 using Aquia Creek sandstone painted white; when Thomas Jefferson moved into the house in 1801, he added low colonnades on each wing that concealed stables and storage. In 1814, during the War of 1812, the mansion was set ablaze by the British Army in the Burning of Washington, destroying the interior and charring much of the exterior. Reconstruction began immediately, President James Monroe moved into the reconstructed Executive Residence in October 1817.
Exterior construction continued with the addition of the semi-circular South portico in 1824 and the North portico in 1829. Because of crowding within the executive mansion itself, President Theodore Roosevelt had all work offices relocated to the newly constructed West Wing in 1901. Eight years in 1909, President William Howard Taft expanded the West Wing and created the first Oval Office, moved as the section was expanded. In the main mansion, the third-floor attic was converted to living quarters in 1927 by augmenting the existing hip roof with long shed dormers. A newly constructed East Wing was used as a reception area for social events. East Wing alterations were completed in 1946. By 1948, the residence's load-bearing exterior walls and internal wood beams were found to be close to failure. Under Harry S. Truman, the interior rooms were dismantled and a new internal load-bearing steel frame constructed inside the walls. Once this work was completed, the interior rooms were rebuilt; the modern-day White House complex includes the Executive Residence, West Wing, East Wing, the Eisenhower Executive Office Building—the former State Department, which now houses offices for the President's staff and the Vice President—and Blair House, a guest residence.
The Executive Residence is made up of six stories—the Ground Floor, State Floor, Second Floor, Third Floor, as well as a two-story basement. The property is a National Heritage Site owned by the National Park Service and is part of the President's Park. In 2007, it was ranked second on the American Institute of Architects list of "America's Favorite Architecture". Following his April 1789 inauguration, President George Washington occupied two executive mansions in New York City: the Samuel Osgood House at 3 Cherry Street, the Alexander Macomb House at 39–41 Broadway. In May 1790, New York began construction of Government House for his official residence, but he never occupied it; the national capital moved to Philadelphia in December 1790. The July 1790 Residence Act named Philadelphia, Pennsylvania the temporary national capital for a 10-year period while the Federal City was under construction; the City of Philadelphia rented Robert Morris's city house at 190 High Street for Washington's presidential residence.
The first U. S. President occupied the Market Street mansion from November 1790 to March 1797 and altered it in ways that may have influenced the design of the White House; as part of a futile effort to have Philadelphia named the permanent national capital, Pennsylvania built a much grander presidential mansion several blocks away, but Washington declined to occupy it. President John Adams occupied the Market Street mansion from March 1797 to May 1800. On Saturday, November 1, 1800, he became the first president to occupy the White House; the President's House in Philadelphia became a hotel and was demolished in 1832, while the unused presidential mansion became home to the University of Pennsylvania. The President's House was a major feature of Pierre Charles L'Enfant's' plan for the newly established federal city, Washington, D. C.. The architect of the White House was chosen in a design competition which received nine proposals, including one submitted anonymously by Thomas Jefferson. President Washington visited Charleston, South Carolina in May 1791 on his "Southern Tour", saw the under-construction Charleston County Courthouse designed by Irish architect James Hoban.
He is reputed to have met with Hoban then. The following year, he summoned the architect to Philadelphia and met with him in June 1792. On July 16, 1792, the President met with the commissioners of the federal city to make his judgment in the architectural competition, his review is recorded as being brief, he selected Hoban's submission. The building has classical inspiration sources, that could be found directly or indirectly in the Roman architect Vitruvius or in Andrea Palladio styles; the building Hoban designed is verifiably influenced by the upper floors of Leinster House, in Dublin, which became the seat of the Oireachtas. Several other Georgian-era Irish country houses have been suggested as sources of inspiration for the overall floor plan, details like the bow-fronted south front, interior details like the former niches in the present Blue Room; these influences, though undocumented, are cited in the official White House guide, in White
General Sherman (tree)
General Sherman is a giant sequoia tree located in the Giant Forest of Sequoia National Park in Tulare County, in the U. S. state of California. By volume, it is the largest known living single-stem tree on Earth. While the General Sherman is the largest living tree, it is not the largest historically-recorded tree; the Crannell Creek Giant, a coast redwood near Trinidad, California, is estimated to have been 15 to 25% larger than the General Sherman tree by volume. That tree was cut down in the mid-1940s. Another larger coast redwood, near 90,000 cubic feet, the Lindsey Creek tree, was reported in a 1905 Humboldt Times Standard article; the General Sherman was named after the American Civil War general William Tecumseh Sherman, in 1879 by naturalist James Wolverton, who had served as a lieutenant in the 9th Indiana Cavalry under Sherman. In 1931, following comparisons with the nearby General Grant tree, General Sherman was identified as the largest tree in the world. One result of this process was that wood volume became accepted as the standard for establishing and comparing the size of different trees.
In January 2006 the largest branch on the tree broke off. There were no witnesses to the incident, the branch — larger than most tree trunks; the breakage is not believed to be indicative of any abnormalities in the tree's health, may be a natural defense mechanism against adverse weather conditions. While it is the largest tree known, the General Sherman Tree is neither the tallest known living tree on Earth, nor is it the widest, nor is it the oldest known living tree on Earth. With a height of 83.8 meters, a diameter of 7.7 m, an estimated bole volume of 1,487 m3, an estimated age of 2,300–2,700 years, it is among the tallest and longest-lived of all trees on the planet. List of largest giant sequoias List of superlative trees List of trees List of oldest trees National Register of Big Trees "What is the largest tree in the world?" Video of a park ranger at Sequoia National Park explaining details about the General Sherman Tree Norton, Marc. "The Karl Marx Tree: How Southern Pacific Railroad killed a socialist colony in the name of creating Yosemite National Park," Red Hills, August 27, 2014
A flood is an overflow of water that submerges land, dry. In the sense of "flowing water", the word may be applied to the inflow of the tide. Floods are an area of study of the discipline hydrology and are of significant concern in agriculture, civil engineering and public health. Flooding may occur as an overflow of water from water bodies, such as a river, lake, or ocean, in which the water overtops or breaks levees, resulting in some of that water escaping its usual boundaries, or it may occur due to an accumulation of rainwater on saturated ground in an areal flood. While the size of a lake or other body of water will vary with seasonal changes in precipitation and snow melt, these changes in size are unlikely to be considered significant unless they flood property or drown domestic animals. Floods can occur in rivers when the flow rate exceeds the capacity of the river channel at bends or meanders in the waterway. Floods cause damage to homes and businesses if they are in the natural flood plains of rivers.
While riverine flood damage can be eliminated by moving away from rivers and other bodies of water, people have traditionally lived and worked by rivers because the land is flat and fertile and because rivers provide easy travel and access to commerce and industry. Some floods develop while others such as flash floods can develop in just a few minutes and without visible signs of rain. Additionally, floods can be local, impacting a neighborhood or community, or large, affecting entire river basins; the word "flood" comes from a word common to Germanic languages. Floods can happen on flat or low-lying areas when water is supplied by rainfall or snowmelt more than it can either infiltrate or run off; the excess accumulates in place, sometimes to hazardous depths. Surface soil can become saturated, which stops infiltration, where the water table is shallow, such as a floodplain, or from intense rain from one or a series of storms. Infiltration is slow to negligible through frozen ground, concrete, paving, or roofs.
Areal flooding begins in flat areas like floodplains and in local depressions not connected to a stream channel, because the velocity of overland flow depends on the surface slope. Endorheic basins may experience areal flooding during periods when precipitation exceeds evaporation. Floods occur in all types of river and stream channels, from the smallest ephemeral streams in humid zones to normally-dry channels in arid climates to the world's largest rivers; when overland flow occurs on tilled fields, it can result in a muddy flood where sediments are picked up by run off and carried as suspended matter or bed load. Localized flooding may be caused or exacerbated by drainage obstructions such as landslides, debris, or beaver dams. Slow-rising floods most occur in large rivers with large catchment areas; the increase in flow may be the result of sustained rainfall, rapid snow melt, monsoons, or tropical cyclones. However, large rivers may have rapid flooding events in areas with dry climate, since they may have large basins but small river channels and rainfall can be intense in smaller areas of those basins.
Rapid flooding events, including flash floods, more occur on smaller rivers, rivers with steep valleys, rivers that flow for much of their length over impermeable terrain, or normally-dry channels. The cause may be localized convective precipitation or sudden release from an upstream impoundment created behind a dam, landslide, or glacier. In one instance, a flash flood killed eight people enjoying the water on a Sunday afternoon at a popular waterfall in a narrow canyon. Without any observed rainfall, the flow rate increased from about 50 to 1,500 cubic feet per second in just one minute. Two larger floods occurred at the same site within a week, but no one was at the waterfall on those days; the deadly flood resulted from a thunderstorm over part of the drainage basin, where steep, bare rock slopes are common and the thin soil was saturated. Flash floods are the most common flood type in normally-dry channels in arid zones, known as arroyos in the southwest United States and many other names elsewhere.
In that setting, the first flood water to arrive is depleted. The leading edge of the flood thus advances more than and higher flows; as a result, the rising limb of the hydrograph becomes quicker as the flood moves downstream, until the flow rate is so great that the depletion by wetting soil becomes insignificant. Flooding in estuaries is caused by a combination of sea tidal surges caused by winds and low barometric pressure, they may be exacerbated by high upstream river flow. Coastal areas may be flooded by storm events at sea, resulting in waves over-topping defenses or in severe cases by tsunami or tropical cyclones. A storm surge, from either a tropical cyclone or an extratropical cyclone, falls within this category. Research from the NHC explains: "Storm surge is an abnormal rise of water generated by a storm and above the predicted astronomical tides. Storm surge should not be confused with storm tide, defined as the water level rise due to the combination of storm surge and the astronomical tide.
This rise in water level can cause extreme flooding in coastal areas when storm surge coincides with normal high tide, resulting in storm tides reaching up to 20 feet or more in some cases." Urban flooding is the inundation of land or property in a built environment in more densely populated areas, caused by rainfall overwhelmi