Types of Drought
To help with drought classification and monitoring, scientists have defined several types of drought:
When dry weather patterns dominate an area.
When low water supply becomes evident in the water system.
When crops become affected by drought.
When the supply and demand of various commodities is affected by drought.
When natural ecosystems are affected by drought.
Drought is the absence of precipitation, rather than the presence of an event such as a hurricane, tornado, or fire. It's often described as a “creeping phenomenon” because it slowly impacts many sectors of the economy and operates on many different timescales.
Just as drought is difficult to define, it’s also difficult to predict and monitor—particularly when marking the beginning and end of a period of drought.
Drought’s effects also vary from region to region. Due to climatic differences, what might be considered a drought in one part of the country may not be a drought somewhere else.