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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。
Based on the data of summer precipitation anomalies from 1981 to 2010 (June - August) in 149 meteorological stations in Sichuan Province, based on the information diffusion theory, by means of constructing the percentage of precipitation anomaly and the risk level of agricultural drought (mild, moderate and severe Severe), introduced the average membership degree of the interval, and discussed the spatial distribution characteristics of agricultural drought risk in different levels of summer in Sichuan Province. The results showed that: (1) In general, the risk level of summer agricultural drought in Sichuan Province is relatively high, with a probability of about 25% -49%, mainly distributed in the northeast, northwest, central and southern parts of the basin as well as western Sichuan The southern part of the southern mountainous area, while the western Sichuan plateau is basically a low-lying area, and from the northern Sichuan Plateau through the central western Sichuan Plateau to the north of the mountainous area in Sichuan formation of a low value; (2) moderate and above agricultural drought risk distribution (3) The probability of mild agricultural drought in the western Sichuan Plateau and southwestern Sichuan is greater than that in the Sichuan Basin and its surroundings Area; (4) compared with the traditional frequency statistics, the results presented in the overall trend with the same, but the values vary; (5) for the first time in Sichuan using the uncertainty analysis, quantitatively revealed the This method can provide a useful reference for similar studies in other areas.