Drought refers to water scarcity and reduction of stream ow, reduction in lake or reservoir stor- age, and lowering of ground-water levels due to a lack of rainfall, and intense sunshine. In the past, drought intensity was evaluated based on the
number of consecutive drought days. These days, it is determined by the duration of water scarci- ty, and the extent of regions that is affected by drought.
Drought damage includes industrial damage,
human injury, and loss of life due to water scarci- ty. Water scarcity means not only a huge decrease in water volume, groundwater, and soil moisture, but also reduced productivity due to industrial water shortages. In Korea, droughts often occur
when a Jangma (East Asian monsoon) front is moving north due to high pressure in the North Paci c High during the summer, which prevents and restricts precipitation.