Inversion and Validation of Surface Soil Moisture Based on the Temperature Vegetation Dryness Index (TVDI)

Abstract

Soil moisture status is one of the important indicators for monitoring soil conditions, and also is the basic information for hydrology, meteorology, agriculture as well as in other fields. To survey soil moisture in large scale can provide valuable information for soil drought and regional flood disaster monitoring. And, enhanced vegetation index (EVI) and land surface temperature (LST) corrected by digital elevation models (DEM), which obtained from Moderate Resolution Imaging Spectro radiometer (MODIS) data of MOD13A2 and MOD11A2 respectively, was proposed to build a feature space. Applying the feature space, the temperature vegetation dryness index (TVDI) was calculated to inverse the surface soil moisture in late May and November, 2010, Hangzhou. Then, the same phase of field survey data was used to validate the inversion results, demonstrating that TVDI index was significantly correlated with the soil moisture in the depth of 20cm which can better reflect the depth of soil moisture.