基于可变模糊评价法的渭河流域综合干旱分区研究

Variable fuzzy evaluation on comprehensive divisions of drought in the Wei River basin

本文利用渭河流域21个气象站及8个水文站1960—2010年的资料,针对气象和水文干旱问题,把干旱分为由无旱到特旱5个等级,建立了渭河流域分区干旱综合评价指标体系;根据干旱综合评价指标体系,采用基于对立统一与质量互变定理的可变模糊评价法对渭河流域分区干旱状态进行了评价;应用累积距平和小波分析法,揭示了该流域分区51年来干旱的时空变化特征。结果表明,该流域干旱程度近年来呈增加趋势并会持续下去,大多数分区干旱程度在1973年和1997年前后发生了渐变式质变,且该流域各分区存在8年和27年左右的干旱周期。因此,该研究方法能定量评价流域分区干旱状况,且弥补了仅用气象或水文干旱指标评价的不足,对指导流域抗旱减灾工作具有重要意义。

For the meteorological and hydrological droughts in the Wei River basin, a drought index system has been established using the data at 21 meteorological and 8 hydrological stations from 1960 to 2010, and the drought is graded into 5-level from normal to extreme drought. Then the drought condition is evaluated by the variable fuzzy evaluation method based on the theory of the unity of opposites and the mutual change law of quality and quantity. Moreover the spatiotemporal variation in the divisions near 51years is analyzed with accumulated departure and wavelet analysis method. The results are as follows：the drought showed an increasing trend in recent years and the trend will continue;the qualitative change points of drought degree occurred around 1973 and 1997 in most of the divisions;there is a drought period of 8 years and 27 years. Therefore, the research results can evaluate the drought condition quantitative-ly and make up for the deficiency of only using meteorological or hydrological drought index.