Abstract:
This study analyzed the evolution trend of drought disaster in the whole country and every provinces from 1949 to 2020 by constructing the comprehensive index series of drought disaster and base on the four indicators series such as crop sown,drought affected,and disaster affected areas,and grain loss due to drought and the spatio-temporal distribution characteristics and change trend of drought disasters in China were analyzed.The statistical results show that rates of drought affected area,disaster affected area and grain loss have increased from 1949 to 2000,by 1.72%/10 a,1.26%/10 a and 0.61%/10 a,respectively,but the drought disaster have decreased gradually from 2001 to 2020 on the time scale.In terms of spatial distribution,the agricultural drought disaster is more severe in the Northeast,Northwest and Huang-HuaiHai regions,where the rates of drought affected area and disaster affected area are more than 15% and 10%.While the drought disaster rate is relatively slow in the South China,Southwest and Middle-lower reaches of the Yangtze River regions,where the rates of drought affected area and disaster affected area are lower than 10% and 5%.According to comprehensive drought index,there are 26 years of above severe drought and 13 years of extreme drought from 1949 to 2020 in China.There were 10 provinces with above severe drought before 1980,but there were expanded to 16 after 1980,which means that China is a country with frequent drought disasters.This study also concluded that climate warming and human activities are the main drivers of the aggravation of drought disasters in China.The annual precipitation in the HuangHuai-Hai,southwest and other regions showed a decreasing trend from 1961-2020,average annual surface temperature showed a significant increasing trend from 1951-2020 in China,with temperature increasing at 0.26℃/10 a.Unsustainable human activities were found to contribute to agricultural drought disasters by disrupting crop water income and expenditure,the drought disaster were more severe,to a certain extent.