Risk assessment of drought disaster in southern China

Abstract:

Abstract: Drought has become an increasing concern in southern China, but the drought risk has not been adequately studied. This study presents a method for the spatial assessment of drought risk in southern China using a conceptual framework that emphasizes the combined role of hazard, vulnerability, and exposure.
A drought hazard map was retrieved with a compound index of meteorological drought method in a GIS environment. Normally, a large variation in the disaster-inducing factor implies a high probability of economic/social losses caused by a drought disaster. The map indicated that areas with a higher risk of drought hazard were mainly distributed in mid-east Yunnan and the basins in eastern Sichuan.
The vulnerability indices were based on climate factors as well as land use, geomorphological types, soil properties, and drainage density. The water preserving capability of purple calcareous soil in the basins in Sichuan and mid-east Yunnan, and the lateritic red soil in northeastern Guangdong is relatively weak. The main geomorphological features in Guangxi and Guangdong are hills, which leads to a serious expectation of soil and water losses. Thus, the main areas with a high risk of drought vulnerability are mid-east Yunnan and the basins in eastern Sichuan.
The exposure indices were based on population density and agricultural production because population and agriculture experience the main impacts of a drought disaster. Higher exposure indices mean higher economic/social losses due to drought disasters. Areas with high exposure indices were mainly distributed in Guangdong and southern Guangxi.
The overall risk was then calculated as the product of the hazard, vulnerability, and exposure. The results indicated a higher risk of drought disaster in the basins in eastern Sichuan,, northeastern Yunnan, and northeastern Guangdong. The main factor influencing the risk of a drought disaster was the hazard, but the vulnerability and exposure also played important roles.