几种干旱指标对西南和华南区域月尺度干旱监测的适用性评价

Applicability Evaluation of Drought Indices in Monthly Scale Drought Monitoring in Southwestern and Southern China

利用西南和华南区域129个气象站逐日和逐月气象数据,计算并对比分析了7种干旱监测指标在该区域的适用性,结果表明:MCI指数和K干旱指数在研究区各季干旱监测中表现均较好,其中,夏、秋季K指数优于MCI指数,冬、春季MCI指数优于K指数;DI指数对冬、春季旱情监测较好;PDSI指数和G EVI指数在夏、秋季监测能力较强;SPI指数夏季监测效果较好;SPIW60指数在各季的监测能力都较弱。K指数对干旱演变过程的刻画能力最强,其次是DI指数;MCI指数在干旱缓解阶段存在监测偏重的情况;SPI、SPIW60以及GEVI指数对干旱的累积效应考虑不够,存在监测偏轻、缓解或解除过快情况;PDSI指数对干旱波动发展过程反映能力较差。综合来看,MCI指数和K指数优于其他指数,K指数更适用于研究区的月尺度干旱监测。

Based on daily and monthly meteorological data from 129 weather stations,the applicability of seven drought indices include in SPI,PDSI,MCI,G EVI,K,SPIW60 and DI in Southwestern and Southern China were evaluated. The results showed that for the ability of drought monitoring at a certain month,MCI and K indices have the best performances in all of the four seasons. And in comparison,K has better ability in summer and autumn and MCI is good in winter and spring. SPIW60 is less effective than others. And the rest four indices performance well in one or two season,for instance,DI can get the best monitoring effect in winter and spring.PDSI and G EVI performance well in summer and autumn,and SPI do best in summer. Refer to the ability of depiction of the developing and changing process of drought,K has the best performance,which can depict the dynamics changes well in each station. Followed by DI,MCI has unreasonable aggravate in ease period. and own to the less consideration of drought accumulative effect,SPI,SPIW60 and G EVI react too fast in ease or remove stage. And the PDSI was poor in depict the fluctuation of drought developing. Taken together,MCI and K are better than other indices,and K is most suitable for drought monitoring in monthly scale in the study area.