Soil moisture analysis using RADARSAT satellite image in the Choke Canyon Reservoir Watershed, South Texas

摘要

The surface soil moisture is very difficult to measure on a river basin scale due to versatile soil types and their associated textures. Consistency of measuring in-situ soil moisture on site is barely obtainable even on a local scale. Recent advances in remote sensing technology have demonstrated that soil moisture can be measured systematically by many optical techniques, such as microwave technology of Synthetic Aperture Radar (SAR). It has the ability to quantitatively measure soil moisture under a variety of topographic and vegetation cover conditions from a satellite system. RADASAT-1 is a space borne SAR imagery satellite. With its all-weather capability, the RADASAT-1 is a promising tool for measuring the surface soil moisture. This research focuses on relations made to soil moisture variability' within RADASAT-1 footprints and on the use of SAR images to develop models of surface soil moisture profile. The case study in the Choke Canyon Reservoir Watershed, South Texas reflects soil moisture spatial distribution patterns in the summer that can be viewed as an extreme situation of water resources management within a semi-arid coastal watershed in 2003.