Agricultural drought monitoring in Dongting Lake Basin by MODIS data

Some remote sensing drought indices are being widely used in northern China, but seldom in humid regions of Southern China. Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor were used in Dongting Lake Basin and precipitation data from Tropical Rainfall Measuring Mission (TRMM) satellite as well. A multi-sensor remote sensing-based drought index called Drought Condition Index (DCI) was established, which based on Vegetation Condition Index(VCI), Temperature Condition Index (TCI) and Tropical Rainfall Condition Index (TRCI). Finally, based on the combination of precipitation and the meteorological drought composite index (CI) from 97 meteorological stations in Hunan Province, the correlation was analyzed and results showed that the linear correlation between DCI and average monthly rainfall and CI was significant. The coefficient passed through 0.01 level tests. Furthermore, by using geo-data and Actuality Map of Land Use, the information of farmland fields were extracted out with the aid of monthly NDVI from MODIS data in Dongting Lake Basin, and the spatial distribution maps of agricultural drought grades were obtained from DCI. Results showed that spatio-temporal pattern of remote sensing monitoring was compared with the real drought condition from the observatories around basin, validity of DCI in drought evaluation were verified. Agricultural drought monitoring based on MODIS and multi-sensor remote sensing data has some promotion and application value.