Shaanxi Province, Drought Disaster Risk Assessment And Zoning

Drought disaster is one of the most serious disasters in the world. Its frequeney, the time that lasts, the area and damage it caused is at the top of all kinds of natural disasters. The fourth assessment in IPCC report said that extreme disastrous weathers such as serious drought had being increasing caused by the global climate warms up. At present, drought disasters as the main faectors that affect the safe Problem of Water resource had became serious unstable factors of the development of the world, and the main bottleneck factor of the national sustainable development. Shaanxi province is located between southeast monsoon climate and northwest continental climate, with a fragile ecological environment, inconstant rainfall, and nine times of drought in every 10-years. Therefore it is important to scientificly estimate drought disaster, which is in order to take right hands, seek effective measures of reducing risks, lighten damage and heighten social economic benefits.According to the domestic and foreign present situation and development trends of drought risk assessment, in the light of principles of natural disaster system theory and disaster risk assessment, based on the meteorological datas of day annual temperature and precipitation of 96 meteorological stations from 1961 to 2008, soil farming water datas between 20cm and 30cm deep, social economic datas of counties in 2008 year of Shaanxi Province, including area square, totaol people of every year, land, GDP, livestock number, financial revenue and drought or flood land area, and GIS data of vegetative cover in 2009, using geographical information systems (GIS), a simple assessment model was built up to assess regional drought disaster risk, which includes disaster-causing factors, disaster-pregnant environment, disaster-bearing bodies and disaster recovery capability. The study compiles county-level maps of drought disaster risk distribution of Shaanxi Province, and tests the zoing result using the losses datas from 1984 to 2007.In this paper, the main conclusions and innovation points are as follows:(1) Drought risk assessment indexes in shaanxi are as below:drought hazard is analysed by composite drought index; drought exposure is studied by average precipitation, soil farming water and vegetative cover; vulnerability includes personal density, ecnomic density, land proportion and livestock per kilometers; recovery capability consists of financial revenue and drought or flood paul received area ratio.(2) The result of drought hazard zoning is that Yulin, east of Yanan and north of the central Shaanxi plain are seriouser hazard areas; west of Yanan, south of the central Shaanxi plain and Shangluo are medium-hazard areas; Hanzhong and Ankang are lighter hazard areas. The result of drought exposure zoning is that highter exposure regions are Yulin and middle-east of the central Shaanxi plain; medium-exposure region is Yanan; south of Shaanxi is lighter exposure region.(3) The result of drought vulnerability zoning is that the vulnerability of the central Shaanxi is bigger than other areas such as Yulin, Yanan, Hanzhong, Ankang and Shangluo. The result of drought recovery capability zoning is that the highter recovery capability districts are the south of Weinan, Xian, Xianyang city, Yanan city, Hanjiang valley and Yunlin; the light districts are southeast of Yunlin and east of Yanan; other districts in this province are secondary.(4) Drought disaster risk index is increasing from south to north and from west to east in Shaanxi Province. Hight risk zonings include Yunlin and the central Shaanxi plain; the boundaries of Yanan, except west, and the central Shaanxi are lower than Hight risk zonings in risk rank; medium risk zonings consists of Yanan and Shangluo; low risk zonings are Hanzhong and Ankang. The zoing result is in accordance with the testing.(5) Innovation points:the paper studied drought risk assessment and zoning using geographical information systems, adopting disaster-causing factors, disaster-pregnant environment, disaster-bearing bodies and disaster recovery capability of drought disaster system, joining natural properties wirh social properties, in order to realize spatial result.