Class Project: Relation between Ground-based Soil Moisture and Satellite Image-based NDVI ES 6973: Remote Sensing Image Processing Instructor:

Soil moisture is critical parameters in climatic and hydrological modeling and vegetation growth. Ground-based point measurement of soil moisture is liable but expensive and impractical for watershed measurement. Remote sensing measurement has provided thriving perspective for spatial and instantaneous measurement of soil moisture. Microwave measurement is effective and successful for surface soil moisture, but influenced by the vegetation and land roughness, and can’t detect the root zone or below-root zone soil moisture. Vegetation growth is heavily dependent on the water availability in arid and semi-arid areas, and the vegetation index from satellites may respond to the change of soil moisture and reflect the soil moisture to some degree. This study analyzed the profile soil moisture characteristics in three different climate and vegetation sites from Feb 2000 through Apr 2004, compared the collocated and coincided soil moisture and MODIS NDVI, and estimated the soil moisture using NDVI by least square regression model. Results showed that the root and below-root zone soil moisture in semi-arid climate has strong correlation with simultaneous NDVI and can be estimated using NDVI during growing season; the root zone soil moisture in humid climate also has moderate correlation with simultaneous NDVI during growing season; below-root soil moisture in humid climate has weak correlation with NDVI and can’t be effectively estimated using NDVI; Soil moisture has weak correlation with NDVI and can’t be effectively estimated using NDVI during non-growing season (Oct-March).