PDSI及sc_PDSI干旱指数在中国西南地区适用性分析  

The applicable analysis of PDSI and self_calibrating PDSI drought indices in southwest China

作　　者：宋琳琳 张强[4,5] 任余龙[6] 李忆平[6] 韩兰英[7] 柳媛普[6] 王素萍[6] Song Linlin;Zhang Qiang;Ren Yulong;Li Yiping;Han Lanying;Liu Yuanpu;Wang Suping(State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Atmosphere Sounding,China Meteorological Administration,Chengdu 610225,China;Meteorology Bureau of Gansu,Lanzhou 730020,China;College of Atmospheric Science,Lanzhou University,Lanzhou 730000,China;Laboratory of Arid Monitoring,Warning and Prediction,Lanzhou Institute of Arid Meteorology,China Meteorological Administration,Lanzhou 730020,China;Northwest Regional Climate Center,Lanzhou 730020,China)

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029 [2]中国科学院大学,北京100049 [3]中国气象局大气探测重点开放实验室,四川成都610225 [4]甘肃省气象局,甘肃兰州730020 [5]兰州大学大气科学学院,甘肃兰州730000 [6]中国气象局兰州干旱气象研究所,甘肃兰州730020 [7]西北区域气候中心,甘肃兰州730020

出　　处：《中国沙漠》2021年第2期242-251,共10页Journal of Desert Research

基　　金：甘肃省青年科技基金计划项目(17JR5RA343);中国气象局大气探测重点开放实验室开放课题(KLAS201706)。

摘　　要：西南地区是中国干旱灾害频发地区,且在全球变暖背景下,干旱发生的频率和程度都有所增加,对农业生产和水资源安全造成威胁。帕默尔干旱强度指数(PDSI,Palmer Drought Severity Index)及在其基础上发展而来的自适应帕默尔干旱强度指数(sc_PDSI,self-calibrating Palmer Drought Severity Index)作为较成熟的干旱监测指标已得到广泛应用。本文利用土壤可含水量(AWC,Available Water Holding Capacity)地理空间模型中土种与AWC的对应关系,反演出西南地区更高分辨率的AWC分布,并采用中国西南70站温度月均值、月累积降水数据,分别计算了PDSI指数及sc_PDSI指数,进而比较分析两种指数的时间变化特征及统计分布性质,探讨二者在西南地区对干旱监测的适用性。结果表明:(1)PDSI与sc_PDSI均反映了西南地区在1965-2010年变干的趋势,但PDSI时间序列振动幅度更大;(2)PDSI的频率分布出现“翘尾”现象,监测到的极端干旱/湿润事件的发生频率高于严重干旱/湿润事件,而sc_PDSI的频率分布则更接近于正态分布;(3)两种指数对2009/2010年西南地区干旱事件的监测结果表明,sc_PDSI对干旱落区和干旱级别的监测均一定程度上优于PDSI,与土壤湿度结果更为接近,而PDSI更易对旱情估计过重;(4)虽然整体上sc_PDSI对PDSI具有一定的调整作用及一定的优越性,但在个别区域(如热带季风气候)并没有体现出调整效果,应用时应当考虑区域因素。The southwestern region is one of the areas where drought disasters frequently occur in China.Under the background of global warming,the frequency and degree of droughts have increased,posing threats to agricultural production and water security.The Palmer drought Severity Index(PDSI)and the self-calibrating Palmer Drought Severity Index(sc_PDSI),which was developed based on PDSI have been widely used as mature ones.In this paper,the correspondence between soil species and available water holding capacity(AWC)included in the soil AWC geospatial model was used to inverse the high resolution AWC distribution in the southwest region.And the monthly mean temperature,as well as the monthly cumulative precipitation data of 70 stations in Southwest China were also used to calculate the PDSI index and sc_PDSI Index.Further comparative analysis of time-varying characteristics of the two indexes themselves and the statistical distribution properties,as well as the discussion of the applicability of both drought indexes in the Southwest area drought monitoring,were also included.The results show that:(1)Both PDSI and sc_PDSI reflect the“drought trend”of Southwest area during 1965-2010,but PDSI is of greater fluctuation amplitude;(2)There’s‘tail’phenomenon in PDSI frequency distribution,showing that the frequency of extreme drought/moist event it monitored is higher than that of severe drought/wet event,while the frequency distribution of sc_PDSI is closer to normal distribution;(3)The monitoring results of the two indexes during the 2009/2010 drought event in southwest area show that,to a certain extent,sc_PDSI is superior to PDSI in the monitoring of drought area and drought level,and is more consistent with soil moisture results,while PDSI is more likely to over-estimate the drought;(4)Although in general sc_PDSI adjusts PDSI to some extent,which makes sc_PDSI as superior,there’s no adjustment in the specific area(tropical monsoon climate).So area factor should be taken into account in any application of these

关 键 词：西南地区 PDSI sc_PDSI 干旱指数 

分 类 号：P429[天文地球—大气科学及气象学]