Chapter 4: Optical/Thermal-Based Techniques for Subsurface Soil Moisture Estimation

HOLZMAN, M. E.; RIVAS, R.

Satellite Soil Moisture Retrievals: Techniques & Applications

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Año: 2016; p. 73 - 89

The aim of this work was to evaluate the aptitude of a simple method based on the relationship between remote sensed estimates of sensible heat flux and vegetation index from MODIS to retrieve subsurface soil moisture. It was shown a high correlation (R2>0.69) between the remotely sensed Temperature Vegetation Dryness Index and soil water content at 10, 40, 60 and 120 cm depths in two agro-climatic zones of Argentine Pampas. The different factors of the approach (spatial resolution, temporal evolution of TVDI parameters) and soil-vegetation system (root depth, vertical integration) influencing the aptitude of the method were discussed. In soils without physical limitations for root exploration and vegetation type with deep root system, the capability of the method to estimate deep water status increases. Finally, the study confirms the usefulness of remote sensed optical/thermal technique for understanding hydrological and ecological processes associated to soil moisture in regions with poor data availability.