There are few çok az places on Earth where people need not be concerned ilgili about flooding.su baskını Any place where rain falls is vulnerable,savunmasız although rain is not the only impetus güç for flood.
A flood occurs meydana gelmek when water overflows or inundates sel basmak land that's normally dry. This can happen in a multitude çokluk of ways. Most common is when rivers or streams dere overflow their bank.kıyı Excessive aşırı rain, a ruptured çatlak dam baraj or levee,su seti rapid ice melting in the mountains, or even an unfortunately placed beaver (i.) kunduz dam can overwhelm mahfetmet a river and send it spreading over the adjacent yakın land, called a floodplain.sel havzası Coastal kıyısal flooding occurs when a large storm or tsunami causes the sea to surge kabarmak inland.
Most floods take hours or even days to develop, giving residents ample bol; geniş time to prepare or evacuate tahliye etmek. Others generate meydana gelmek quickly and with little warning. These flash ani floods can be extremely dangerous,instantly hemen turning a babbling şırıldayan brook ırmak into a thundering kocaman wall of water and sweeping silip süpürmek everything in its path yol downstream.akıntı yönünde
Moving water has awesome destructive yıkıcı power. When a river overflows its banks or the sea drives inland, structures poorly equipped to withstand direnmek the water's strength are no match. Bridges, houses, trees, and cars can be picked up and carried off. The erosive aşındırıcı force of moving water can drag çekmek dirt çamur from under a building's foundation,temel causing it to crack and tumble.yıkılmak
When floodwaters recede,geri çekilmek affected areas are often blanketed örtmek in silt alüvyon and mud. The water and landscape can be contaminated kirlenmiş with hazardous tehlikeli materials, such as sharp debris,enkaz pesticides,böcek zehiri fuel, and untreated işlenmemiş sewer lağım. Potentially dangerous mold küf bağlamış. bloom ham demir can quickly overwhelm water-soaked çekmek structures. Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks salgın of deadly waterborne diseases like typhoid, hepatitis A, and cholera.
But flooding, particularly in river floodplains, is as natural as rain and has been occurring for millions of years. Famously fertile verimli floodplains like the Mississippi Valley in the American Midwest, the Nile River valley in Egypt, and the Tigris-Euphrates in the Middle East have supported agriculture for millennia çoğul, millenium because annual flooding has left millions of tons of nutrient besin-rich silt deposit birikinti behind.
Most flood destruction is attributable dayandırılabilir to humans' desire to live near picturesque resmedilmeye değer coastlines and in river valley.vadi Aggravating kötüleştirmek the problem is a tendency meyil for developers to backfill geri doldurma and build on wetlands that would otherwise act as natural flood buffers.tampon
Many governments mandate koruma altına almak that residents of flood-prone meyilli areas purchase satın almak flood insurance sigorta and build flood-resistant structures. Massive efforts to mitigate hafifletmek and redirect inevitable kaçınılmaz floods have resulted in some of the most ambitious engineering efforts ever seen, including New Orleans's extensive levee system and massive dikes set and dams in the Netherlands. And highly advanced computer modeling now lets disaster authorities predict öngörmek, tahmin etmek with amazing accuracy where floods will occur and how severe sert they're likely muhtemel to be.
environment.nationalgeographic.com