Drought Risk Assessment And Index Insurance Ratemaking Of Winter Wheat In Shaanxi Province

Our country is a great agriculture country. Natural disasters often cause serious damages to the people’s property, also poses a great impact to China’s economic and social development. Shaanxi province is one of the main region of winter wheat production in China. Shaanxi Agricultural production is always in a state of flux due to its weak agricultural economic foundation, fragile ecological environment, poor ability to resist natural disasters. As an effective way to spread the risk of agriculture, Agricultural insurance can reduce the impact from natural disaster (especially drought) to the growth of winter wheat. But there are still many problems such as survey, claims, especially for rates set included. Therefore, it is very important to make the reasonable insurance risk zoning and insurance ratemaking to mitigate the effect of winter wheat production and allocate production resources reasonable.This article takes winter wheat as research object and studies the risk assessment of droughts and insurance rate making in Shaanxi Province. Considering water sensitivity coefficient and aswp period precipitation, Using the data of growth period, meteorological data and production data to build the winter wheat drought index in Shaanxi Province and separate the influence degree of drought on yield. Divide the drought index to several level range. On basis above, we analysis the timing and region distribution of winter wheat, risk zoning and metrology index insurance zoning. Use yield distribution model method to set insurance rates, finally we explore the designing of metrology index insurance product.(1) Based on relative wetting degree index, according to the crop characteristics and moisture sensitivity, impact on water to crops, we develop the drought which fits Shaanxi province. It has obvious advantages than relative wetting degree index on the describe of drought conditions by growth period. For trend production simulation, we switch the best from Lagrange interpolation method, function method, moving average method so that overcoming the weak point of different methods, promoting dividing effect of metrology production.(2) Nearly 30 years of drought frequency and the rate of production in Shaanxi Province are different according to the zonal distribution. The demand for water of wheat in key growth period is larger and the drought frequency and production rate are higher, too. The distributions of them have good consistency. In northern Shaanxi, Guanzhong region and parts of Southern Shaanxi, the production rate of winter wheat has increased by nearly 30 years, and the production rate in northern Shaanxi fluctuates significantly. In addition,the growth period of the production rate change trend is not the same.(3) According to the growth period and relative wetting degree index to build the model of winter wheat drought in Shanxi Province, considering aswp period precipitation and using statistical models to separate the effects of the drought on yield. We can reduce the limitations of the drought sensitivity differences in different growth period by the traditional classification method and make the analysis of drought more accurate.(4) Make drought risk zoning of the winter wheat in Shaanxi Province by drought risk degree (Z), production of risk (D) and disaster relief performance index (R), we can conclude that the production risk index and risk degree of winter wheat are different by latitude and they are gradually reduced from north to south. While disaster performance index is enhanced step by step from north to south by zonal distribution. The risk zoning of Winter wheat in Shaanxi province is reduced from north to south, too. The risk of Northern Shaanxi is far greater than Guanzhong region and Southern Shaanxi.(5) Using data envelopment analysis (DEA) to improve the traditional specialization index (SA) method, we can consider both the scale efficiency and pure technical efficiency to make model more accurate. The division scope of the risk of winter wheat in Shaanxi policy-related insurance (PT) and weather index insurance (WT) is sharply decreased.(6) Select eight forms of distribution simulation of winter wheat yield distribution, we can conclude that the time series of yield per unit on different areas in Shaanxi Province are not simply normal distribution. Johnson SB model applies to most areas (but this model is widely used abroad, but seldom studied in domestic). No correlation in found between the selection of the models and regional distribution. The dry rate of yield distribution model method is different by latitude and the high value area is in Northern Shaanxi.(7) Design the winter wheat drought index of insurance products in Shaanxi province and further changes to the premium rate of the whole growth period, we can conclude that the high value area of drought index insurance rate mainly concentrate in the north of Shaanxi and the low value area are mainly distributed in most of southern Shaanxi. The weather index insurance comprehensive rate values are greater than the area yield insurance. This could be due to comprehensive consideration of human activities and other external conditions and it may slow down the fluctuation of winter wheat yield caused by meteorological conditions changes.