Analysis of spatial distribution characteristics of summer agricultural drought hazard in Sichuan Province during recent 30 years

In this study,the spatial distribution characteristics of every agricultural drought hazard level in summer in Sichuan province were explored based on the data of summer( JJA) precipitation anomaly of 149 meteorological stations in this region from 1981 to 2010 and the information diffusion theory,and through the trapezoidal fuzzy membership functions built between precipitation anomaly percentage and various agricultural drought hazard levels( light,moderate,heavy and severe) and introducing interval average membership degree. The results show that:( 1) generally,the summer agricultural drought hazard level in Sichuan Province is relatively high,the occurrence probability of which ranges between 25% to 49%,and it mainly distributed in the northeast,northwest,central and southern part of Sichuan Basin and the south of southwest Sichuan mountain area. The relatively low-occurrence area is western Sichuan plateau,and a low-value channel formed from the northern part of the west Sichuan plateau and across the middle of the west Sichuan plateau till the northern part of the southwest Sichuan mountain area;( 2) moderate and above agricultural drought hazard levels are mainly distributed in the basin and its surrounding areas,and a continuous high value areas exist in the northwest and northeast of the basin;( 3) the occurrence probability of light agriculture drought hazard in western Sichuan plateau and southwestern Sichuan mountain areas is greater than Sichuan Basin and its sourroundings in Sichuan Province;( 4) compared with the result of traditional statistics,the results of this paper is consistent with the overall trend,and only has a slight difference in value;( 5) the uncertainty analysis method is first used for Sichuan Province to quantitatively reveal the characteristics of the spatial distribution of different agricultural drought hazard levels,but it can provide a reference to similar studies in other regions.