The National Drought Mitigation Center conceptually defines drought as “a protracted period of deficient precipitation resulting in extensive damage to crops, resulting in loss of yield”. Three indicators of drought include below normal soil moisture, reduced stream flow, and, most obviously, lack of precipitation. These indicators can be kept track of in order to help mitigate the effects of drought. The U.S.
Drought monitor makes maps of the United States that show severity of droughts available to the public (Fig. 1). Nick Arya in his article, “Write a brief note on the characteristics of Drought”, lists five major characteristics of drought. The first essential characteristic of drought is that it builds over time with an increasing scarcity of water.
The second characteristic says that because drought builds over time it does not have a well-defined start. And like the beginning, the end of drought isn’t well-defined either.
The end comes gradually, except in extreme cases where a long spell of heavy rainfall causes the end. The fourth characteristic says that drought is either localized or regional, depending on the severity of the drought. The area affected by the drought is generally an elliptical shape rather than a circular shape.
The effects of drought are far reaching, even if the drought itself is localized. In the article “What are the Effects of Drought?”, Larry West describes some of the lasting effects of drought. One of the more obvious effects of drought is widespread thirst, especially in underdeveloped regions where water is not as readily available as in industrialized countries. Along with a reduction in drinking water, existing stores of drinking water can become contaminated because fresh water is not being introduced to the system. Contamination of drinking water causes disease to spread through populations. Because drought conditions are due to a lack
References: Hanson, R.L., 1991, Evapotranspiration and Droughts, in Paulson, R.W., Chase, E.B., Roberts, R.S., and Moody, D.W., Compilers, National Water Summary 1988-89--