Assessment Of Drought Disaster And Analysis On The Influencing Factors In Snaanxi

In this paper, based on the 50 year statistical data of precipitation , temperature and 44 year agricultural drought of Shannxi from 1950 to 2000,a index system of drought disaster assessment is built : drought standard index, agricultural drought index, decrease percent of grain crop . Drought risk assessment model are built by information diffusion theory .Results show that the drought disaster is increasing and is the most serious in the time 1990s and 1970s, main agricultural drought is great disaster incidents , drought index is proportionate to the decrease percent of grain crop. In spatial distribution, in the north of Shaanxi the drought is very serious, in the south of Shannxi drought is light. Using humorous wave and power chart, changing period of drought and waterlogging are analysed , drought and yield of grain crop is simulating forecasted, shows that drought is lessening in 21's 10 year in the Northwest. In the end the influencing factors and the occurrences of drought disaster are compared and analysed, for example, precipitation, temperature, the El Ninon year, SOI , sunspots, surface runoff low season. The researches play important role in preventing, predicting and reducing drought to every department.The text is divided into six chapters altogether as follows:Chapter 1: An introduction. It expatiates background, content and meaning of the study, and elaborates domestic and international research trends, and puts forward methods of this paper, and proposes the possible place of innovation of this paper.Chapter 2: Agriculture weather situation about Shannxi. It Introducesresources of agricultural climate, formation of agricultural climate and agriculture weather disasters, and induces agriculture weather characteristics of Shannxi.Chapter 3: The valuation index sign of drought disaster. In this chapter, the concepts of drought is introduced simply and the index sign system of the drought disaster valuation is set up, namely, drought standard index, agricultural drought index, decrease percent of grain.Chapter 4: The history evaluate of drought disasters of Shannxi. The characteristics of drought of Shannxi are gained by analyzing the data of drought and agricultural drought area from 1951 to 2000. The characteristics of drought of Shannxi are: the occurrence rate of drought is 40%, average 2.5 years are once, and among them big and drought occurrence rate is 26% and the heavy drought occurrence rate is 10%. The dry trend is 1990s at most, 1970s is the second, 1950s the third, and 1980s is minimal. In spacial distribution , the drought contain obvious increment trend in each area of Shannxi, north dry more and seriously, south compare lightly.Chapter 5: Analysis about influencing factorizations of drought disaster in Shannxi. The influencing factors and the occurrences of drought disaster are compared and analysed and there are following conclusions. Drought disaster has relation to precipitation, temperature, the El Ninon year, SOI , sunspots, surface runoff low season .Chapter 6: The risk valuation and the influence trend estimate of agricultural drought disaster. Using humorous wave and power chart, changing period of drought and waterlogging are analysed , drought and yield of grain crop is simulating forecasted, shows that drought is lessening in 21's 10 year in the Northwest.