Droughts: The End of the American West Essay -- Climate Change and Dro

Droughts are one of the most expensive natural hazards and have the potential to last for months or even years (U.S. Drought Portal). Along with famine and flooding, droughts are considered one of the top three threats to the population (Oblack). A drought is defined as an unusually long period of time with persistent lack of precipitation that causes serious problems. Several factors that affect the severity of a drought are the degree of moisture deficiency, length, size, and location of where the drought occurs (Droughts). A drought can be categorized four ways. A Meteorological drought occurs when there are significantly lower levels of precipitation than normal. This type of drought is dependent on the region because what would be considered normal precipitation in one area could be different in another region. Agricultural droughts refer to when the amount of moisture is less than what the crop in that area requires. Hydrological droughts are when the water supply in the surface and subsurface of the ground is below normal. Socioeconomic are when the lack of water begins to affect people (Droughts). Droughts are caused when there is less rainfall then normal on a region. When the air sinks (subsidence) there is compressional warming or high pressure, which limits the formation of clouds. As a result, there is lower humidity and less precipitation (Predicting Droughts). Additionally, if there are higher temperatures or shifts in the wind pattern this could cause the evaporation of moisture in the ground to increase (Plumer). Droughts can be aggravated by people’s overuse through heavy pumping and farming of marginal lands that puts a strain on the water supply. Additionally people affect droughts by damming rivers. ... ...id W. Hyndman. Natural Hazards and Disasters. 3rd ed. Australia: Brooks/Cole, 2011. Print. Oblack, Rachelle. â€Å"What Causes Droughts?† About.com. N.p., n.d. Web. 10 Apr. 2013. . Plumer, Brad. â€Å"What We Know about Climate Change and Drought.† Wonkblog. Washington Post, 24 July 2012. Web. 10 Apr. 2013. . â€Å"Predicting Droughts.† National Drought Mitigation Center. N.p., n.d. Web. 10 Apr. 2013. . â€Å"Predicting Droughts with Greater Certainty.† Science Daily. N.p., 3 June 2009. Web. 10 Apr. 2013. . U.S. Drought Portal. NIDIS, n.d. Web. 10 Apr. 2013. .