In terms of natural factors, drought is mainly related to the occasional or periodic reduction of precipitation. From the perspective of human factors, the causes of drought caused by human activities are mainly the following four aspects: First, a large increase in population has led to a growing shortage of limited water resources. The second is that the forest vegetation is destroyed by human beings, the water storage function of plants is lost, and the extraction of groundwater leads to the reduction of groundwater and soil water. Third, human activities have caused a lot of water pollution, reducing the available water resources. Fourth, the waste of water is serious, especially in agricultural irrigation in China, which leads to a shortage of water resources.
