VIEW: Drought
Drought
Droughts occur when a region experiences unusually low precipitation for months of years. Periods of drought may create or worsen water shortages. Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The southern United States is experiencing a drought.
Droughts occur when a region experiences unusually low precipitation for months of years. Periods of drought may create or worsen water shortages. Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The southern United States is experiencing a drought. Listen to the following podcast:Drought
Listen to the following podcast:
Although the causes for drought are usually natural, human activities have increased the impact of droughts. For example, deforestation keeps trees from returning water to the atmosphere by transpiration, breaking a part of the water cycle. Overgrazing, improper soil management and poor crop selection can stress local water supplies. Because it is difficult to predict when a drought will occur, it is difficult for countries to predict how serious water shortages will be each year.
Droughts have many consequences. When soil loses moisture it may blow away. This happened during the Dust Bowl in the US in the 1930s. As the moisture content of soil diminishes, agriculture is quickly affected. Wildfires also become much more common during times of drought, as are flash floods and desertification. Wind-blown dust and ash can affect air quality locally and afar.
Watch the following video.
Sources: PBS Learning Media, USOE OER Resource Guide for Earth Systems, Heat Waves and Droughts. Retrieved from http://www.ck12.org/earth-science/Heat-Waves-and-Droughts/lesson/Heat-Waves-and-Droughts/ on January 25, 2014.