不同干旱评估方法在滇中地区的适用性研究

不同干旱评估方法对干旱的识别能力不同,研究适合滇中地区的干旱评估方法很有必要。基于滇中地区月降水量、农作物受旱面积、因旱临时饮水困难人口和因旱粮食减产量资料,对比分析了降水量距平百分率(P a)、标准化降水指数(S PI)、Z指数(Z)、农作物受旱率(I)、因旱临时饮水困难人口比率(Y)五种干旱评估方法确定干旱等级的一致率。结果表明,年尺度上,P a、S PI、Z确定的干旱等级平均一致率在74%~82%之间,季尺度上三种方法的平均一致率在40%~57%之间;I、Y的平均一致率为54%。P a、S PI、Z与I、Y确定的干旱等级在年尺度上差异较大,而在季尺度上P a确定的干旱等级与I、Y确定的干旱等级的一致率较高;P a相对其他四种方法更适合用于滇中地区的干旱评估。

Application of Different Drought Evaluation Methods in Central Yunnan

It is important to find the applicative methods for specific area to evaluate drought. In this paper, the precipitation, drought area of agriculture, population with temporary drinking problem and food reduction yield due to drought were collected. The percentage of precipitation anomalies(Pa), standard precipitation index (SPI), Z-index (Z), crop drought rate (I) and temporary population with drinking water difficult to population ratio (Y) are used to evaluate drought grade in different temporal and spatial of central Yunnan. The results show that the concordance rate of drought grade computed by Pa, SPI and Z methods varied from 74% to 82% in yearly scale, and the concordance rate of drought grade varied from 54% in seasonal scale; the concordance rate of drought grade varied from 40% to 57% by using I and Y methods; although the drought grade have more difference using Pa, SPI, Z methods and using I, Y mehods; but the concordance rate of drought grade computed by Pa, I and Y is relatively high in seasonal scale; compared with other methods, Pa is the most suitable method for estimating drought in central Yunnan.