Drought Disaster Risk Assessment Of Winter Wheat

Drought disaster is one of the most common disasters in the world, it has a profound impact on the natural eco-system and human society. According to the Fourth Assessment report’s conclusions of Intergovernmental Panel on Climate Change (IPCC), global warming has become an indisputable fact. Under the background of global warming and drying trend in the northern, extraordinarily serious droughts grow in number and the scope of effect is also increasing. Because of the geographical position, topography and climate, Dezhou and Liaocheng city become one of the most serious drought areas in China, and drought limits the winter wheat production. Based on four factors of drought disaster risk, with meteorological and agricultural data, this article unifies the natural and social properties of the drought disaster by AHP, WCA and Index of natural disasters. Finally, this article builds drought disaster risk model based yield loss, combined with GIS to achieve spatial visualization. The research results can provide informative data support to the defense and governance, resource development and utilization of drought, which also has an important significance for the sustainable development of agriculture and meteorological services in agricultural production. The paper primary coverage is as follows:(1) Analyzing the correlation between percentage of precipitation anomaly and relative meteorological yield in different winter wheat growth periods. Precipitation anomaly percentage relative meteorological yield percentage are positively correlated in all regions in the whole growth period, soil water period and sow-tillering; they are negative correlated in winter-erecting stage and flowering-maturity stage.(2) According to the quantitative relationship between relative meteorological yield and precipitation anomaly percentage, time and space distribution characteristics of drought disaster-causing factor’s threshold is got. The elongation-heading stage’s threshold is the minimum, production reduction of winter wheat is most likely to occur; the second is the whole growth period and soil moisture before planting stage; threshold in winter-erecting stage is maxium.The largest and smallest threshold region are Wucheng and Laoling county in the whole growth period, Yanggu and Xiajin county in soil moisture before planting stage, Laliing and Xiajin in sow-tillering stage, Laoling and Linyi county in winter-erecting stage, Pingyuan and Qihe in elongation-heading stage, Dezhou and Chiping county in flowering-maturity stage. (3) Constructing the drought disaster risk model carries on the risk regionalization combined with GIS. In the end drought disaster risk zoning maps in each growth period of winter wheat are got. The smallest drought disaster risk value region is Ningjin county and the largest region are Qingyun and northeast of Laoling county in the whole growth period, northeast of Ningjin county and southwest of research area in soil moisture before planting stage, Ningjin county and Dezhou in sow-tillering stage, Xiajin and Qingyun county in winter-erecting stage, Chiping and Pingyuan county in elongation-heading stage, Xiajin and Ningjin county, Dezhou and Qingyun county in flowering-maturity stage.Comparing with the actual disaster data to test the accuracy of the results and the zoning result is in accordance with the testing.