干旱严重程度指数(DSI)在山东省干旱遥感监测中的适用性

Applicability of Drought Severity Index(DSI) in Remote Sensing Monitoring of Drought in Shandong Province

选择一个合适的干旱遥感监测指标,对于及时准确评估干旱对农作物生长影响有重要意义。本文综合植被指数和蒸散发指数,构成干旱严重程度的指数(DSI),并定量评价DSI在山东地区干旱监测的适用性,以期为该区干旱遥感动态监测提供科学依据。在定量分析DSI适用性的过程中,采用相关分析方法,针对基于标准化降水指数(SPI)长时间序列中的典型干旱时期,将月尺度的DSI、归一化干旱指数(NDDI)、温度植被干旱指数(TVDI)分别与SPI、土壤相对湿度(RSM)进行皮尔森相关关系分析。结果表明,SPI、RSM与DSI的相关系数分别在0.40、0.30左右,整体上高于SPI、RSM与NDDI和TVDI的相关性。此外,DSI表示的旱情时空分布准确地捕捉到了历史时期山东各地区的典型干旱事件的发生及其干旱的变化过程。DSI可以反映气象干旱和农业干旱,对山东干旱遥感监测有较好的适用性。

It is important to select a suitable drought remote sensing monitoring index for timely and accurate assessment of the impact of drought on crop growth.In this paper,the vegetation index and evapotranspiration index were integrated to form the drought severity index(DSI),and the applicability of DSI was quantitatively evaluated in drought monitoring,in order to provide scientific basis for remote sensing dynamic monitoring of drought in Shandong province.In the process of quantitatively analysis of DSI applicability,the Pearson correlation analysis was carried out on the monthly scale DSI,Normalized Difference Drought Index(NDDI),Tempera-ture Vegetation Drought Index(TVDI)and Standard Precipitation Index(SPI),Relative Soil Moisture(RSM)in the typical drought period based on the long-term sequence of the SPI,respectively.The results showed that the correlation coefficients between SPI,RSM and DSI are about 0.40 and 0.30 respectively,which were higher than the correlation between SPI,RSM and NDDI,TVDI.In addition,the occurrence of typical drought events and the change process of drought were accurately described by the spatial-temporal distribution of DSI in Shandong province during the historical period.The meteorological drought and agricultural drought was reflected by DSI,which indicated the good applicability of DSI for remote sensing monitoring of drought in Shandong province.