Elevation effect on TVDI-based soil moisture retrieval algorithm using MODIS LST and NDVI products

Generally, soil moisture plays an important role in water cycle, water resources and other diverse applications over land. Passive microwave remote sensors (e.g., ASCAT, AMSR-E, SMOS, and SMAP) have successfully used for estimating the amount of soil moisture irrespective of their low temporal and special resolutions. In this study, we present a TVDI (temperature-vegetation dryness index)-based soil moisture retrieval algorithm based on visible and infrared remote sensors. The TERRA/MODIS products such LST (MOD11A2) and NDVI (MOD13A2) data were used. Far-East Asia area including the Korean peninsula were investigated for the case study. In particular, we found the elevation dependence on the soil moisture retrieval. We developed a correction method for this elevation effect. The proposed TVDI-based soil moisture algorithm in visible and infrared bands were compared and validated with soil moisture contents estimated from GCOM-W1/AMSR-2 observations in microwave bands.