Spatial and temporal distribution and trend in flood and drought disasters in East China.

Frequent floods and droughts have brought serious impact on economy, society and living environment in East China. Based on the disaster census data of rainstorm-induced flood (including landslide and mud-rock flow) and drought disasters in 637 counties (districts) in East China, the distribution and change of flood and drought disasters were analyzed. The results indicate that the number of records of flood disaster increased at a rate of 77.4 times per decade from 1984 to 2010, while that of drought disaster had no significant trend in East China as a whole. Population affected by floods and droughts increased at rates of 8.7 million and 3.8 million persons per decade, respectively, and the direct economic losses increased at rates of 12.6 billion and 1.9 billion Chinese Yuan per decade respectively, whereas the affected area and the total failure area of crops caused by floods and droughts showed no clear trends. Spatially, the number of records of floods in the southern parts of East China was higher than that in the northern parts, and Anhui, Jiangxi, Zhejiang and Fujian had more records of affected population, deaths, affected crops, total crop failures and direct economic losses, as well as more affected population and deaths. The affected crop area and total crop failure area by floods were also larger in Anhui, Jiangxi and Jiangsu. Drought disaster had higher number of records of affected population, affected crops, total crop failures and direct economic losses in Anhui, Jiangxi, Zhejiang and Shandong, and also affected more people and larger area of crops, leading to larger area of total crop failures and higher direct economic losses in Anhui, Jiangxi and Shandong. The results can provide reference for disaster risk regionalization and environmental risk assessment in East China.