The Integrated Surface Drought Index (ISDI) as an Indicator for Agricultural Drought Monitoring: Theory, Validation, and Application in Mid-Eastern China

Based on the concept of the new drought index called Vegetation Drought Response Index (VegDRI) using data-mining technology, an Integrated Surface Drought Index (ISDI) was established in this study. ISDI improved the original model, adding remote sensed temperature information into the input factors. This index attempt to describe drought from a more comprehensive perspective, the integrated information including: traditional meteorological data, satellite-derived earth surface water and heat environments, vegetation conditions, and inherent properties of the earth´s surface. The Cross-validation results indicated that ISDI construction models for three phases of growth season have very high regression accuracy. The practical application of ISDI in mid-eastern China during the reported dry year 2009 also demonstrated that it can provide accurate and detailed drought condition both at regional and local scale. This investigation showed that ISDI has good application potential for drought monitoring across China.