近30年四川省夏季农业干旱危险性空间分布特征分析

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

利用四川省149个气象站点1981-2010年（6-8月）夏季连续降水距平资料,基于信息扩散理论,通过构造降水距平百分率和农业干旱危险性等级（轻度、中度、重度和严重）之间的梯形模糊隶属函数,引入区间平均隶属度,探讨了四川省夏季不同等级农业干旱危险性的空间分布特征。结果表明,（1） 总体上,四川省夏季农业干旱危险性水平是比较高的,发生几率约在25%~49%之间,主要分布在盆地的东北部、西北部、中部和南部以及川西南山地的南部地区,而川西高原基本上为低发区,并且从川西高原北部穿越川西高原中部到川西南山地北部形成了一条低值带;（2） 中度及以上农业干旱危险性主要分布在盆地及其周边地区,并且在盆地西北部和东北部易形成集中连片的高值区;（3） 川西高原和川西南山地出现轻度农业干旱危险性的概率要大于四川盆地及其周边地区;（4）与传统频次统计结果相比,所提结果在整体趋势上与之一致,只是在数值上有所差异;（5） 首次在四川地区采用不确定分析方法,定量地揭示了该地区不同等级农业干旱危险性的空间分布特征,该方法可为其他地区的类似研究提供有益借鉴。

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.