Estimation of the soil moisture using thermal inertia and MODIS satellite data imagery: A case study of Mortazieh area

Abstract

Soil moisture controls many processes in the climate and is considered as a very important variable in the ecosystem and a basic parameter of the environment. It directly influences the life of plants, animals and microorganisms and plays a major role in the energy exchange between air and soil. The purpose of this study is to estimate the surface moisture of soil using the temperature indicators of the earth surface and the inertia of apparent heat. Therefore, MODIS images were used in Mortazie area of Yazd province in two different time periods, one from Feb, 8, 2018 to Feb, 14, 2018 and the other in the summer from July, 4, 2018 to July, 9, 2018. Also, the temperature-vegetation drought index, mostly used in previous research on soil moisture was applied to evaluates results. The apparent thermal inertia was obtained from images of morning and evening modes from Terra and Aqua satellites. A linear relationship was established between the temperature-vegetation drought index and the apparent heat inertia on specific days. The RMSE and R2 were found to be 0.15 and 0.86 on July, 7, 2018 and 0.18 and 0.76 on Feb, 9, 2018 respectively. The overall results showed a linear and direct relationship between the apparent thermal inertia and the TVDI surface moisture index.

Keywords

• land surface temperature (lst)
• normalized differential vegetation index (ndvi)
• soil moisture
• apparent thermal inertia
• mortazieh area