基于多源数据的2001—2010年我国干旱时空分布特征

A multi-index evaluation of drought characteristics in China from 2001 to 2010

准确和全面评价我国陆地干旱时空变化格局,有助于防旱减灾及评估生态系统的稳定性及其对气候变化的响应.利用气象和遥感观测数据,选取3类干旱指数,包括仅基于降水数据的标准化降水指数(SPI)、基于2层土壤模型的帕尔默严重性干旱指数(PDSI)及基于遥感植被指数信息的干旱严重性指数(DSI),对比分析了我国2001-2010年的干旱时空分布特征.结果表明:1)就国家尺度上而言,2001-2010年,我国干旱程度没有呈现显著变化的趋势(P>0.05),3类干旱指数在2001-2010年变化趋势基本一致;SPI和PDSI在时间尺度上的相关性达到66%;2)时间尺度上,2001,2006和2009年是那个10年内干旱程度最大的3个年份;3)我国干旱变化在南北地区有着不同的趋势:东北地区及北部地区(华北平原一带)干旱化范围和程度在减弱;而南部地区,特别是西南地区干旱影响的范围在加大,干旱程度呈严重的趋势.

Accurate and comprehensive evaluation of the spatio-temporal pattern of terrestrial ecosystem under drought in China was considered to be helpful for drought prevention and disaster reduction,assessment of ecosystem stability and its response to climate change.Coupled with meteorological and remote sensing data,three types of drought indices,including SPI (standardized precipitation index) based on precipitation data,PDSI (palmer drought severity index) based on two-layer soil model,and DSI (drought severity index) based on remote sensing vegetation index information,were selected to analyze the spatio-temporal distribution of drought in China from 2001 tO2010.It was showed that: 1) None of significant drought trends ( P >0.05) was found in a decade at national scale,the trend of three drought indices during 2001-2010 was corresponded with each other,and the correlation between SPI and PDSI was 66%;2) The years of 2001,2006 and 2009 were the extreme drought years in a decade;3) The changes in drought in the north and south regions of China had different trends: The extent and degree of drought was weak in the Northeast China and the northern region (North China Plain),while the degree of drought had a tendency of aggravating in the southern region of China,especially in the southwest region.