几种干旱评估指标在宁夏的应用对比分析  

Application of Three Drought Evaluation Indices in Ningxia

作　　者：王素艳[1,2] 郑广芬[1,2] 杨洁[1] 李欣[1] 

机构地区：[1]宁夏气象防灾减灾重点实验室,宁夏银川750002 [2]宁夏气候中心,宁夏银川750002

出　　处：《中国沙漠》2012年第2期517-524,共8页Journal of Desert Research

基　　金：宁夏自然科学基金项目(NZ09198;NZ08162);国家科技支撑项目(2007BAC29B04);2009年中国气象局气候变化专项(CCSF-09-04);国家公益性业专项(GYHY201006023);宁夏回族自治区科技攻关项目(KGX-12-09-12)共同资助

摘　　要：简要分析了几种干旱评估指标(Pa、K、SPI、PDSI和CI)与实况的等级差异;重点对比分析了Pa、K指数和SPI指数的干旱频率、干旱等级一致率、空漏评估率等与干旱实况的差异。结果表明,Pa、SPI指数和PDSI指数的评估效果接近;CI指数的评估效果与K指数接近。大部分年份Pa、K指数和SPI指数的等级较实况偏低,K指数更接近实际等级;大部分地区K指数较Pa和SPI指数反映的干旱频率高,K指数放大了干旱频率,尤其放大了中旱频率,Pa和SPI指数明显缩小了干旱频率;K指数的绝对一致率和相对一致率均高于Pa和SPI指数,大部分出现干旱的年份,K指数都能体现出来;Pa和SPI指数各等级的一致率差异不大。同时,K指数的空评估率较Pa和SPI指数高,漏评估率最低,其空、漏评估率之和最小,而且春旱小于其他3个季节的干旱。综合分析,K指数和CI综合干旱指数评估效果较好,但需进一步改进以适宜宁夏应用。The differences between drought degree assessment by indices as Pa,K,SPI,PDSI and CI,and results from the reality were analyzed from aspects of drought frequency,consistency degree,the vacancy and the miss drought rate of the index assessment.Results indicate that the evaluating effectiveness of these five indices is approximate.But in many years,the drought degrees evaluated by Pa,SPI and K indices are lower than the real,and that by K index is closest to the real.In many areas,the drought frequency evaluated by K index is higher than that by Pa and SPI,showing K index magnifies the drought frequency,especially the frequency of middle drought.In contrast,Pa and SPI indices shrink the frequency obviously.The absolute and the relative consistency rates of K index are all higher than that of Pa and SPI;the difference of consistency rate between Pa and SPI is not evident.Meanwhile,the vacancy rate of K index is higher than that of Pa and SPI,but the miss rate is lower than the two latter;the sum of the vacancy and the miss rates of K index is the lowest,and which in spring is lower than those in other three seasons.In conclusion,the evaluate effectiveness of K and CI is better than the other indices,but they must be improved to fit application in Ningxia.

关 键 词：干旱评估指标 宁夏 对比分析 

分 类 号：P426[天文地球—大气科学及气象学]