|Mattikalli, Nadish - NASA|
|Engman, Edwin - NASA|
Submitted to: Proc Int Society of Photogrammerty & Remote Sensing Workshop on Mapping
Publication Type: Proceedings
Publication Acceptance Date: December 1, 1995
Publication Date: N/A
Technical Abstract: A raster-based geographical information system (GIS) has been employed to monitor spatial and temporal variability of surface soil moisture derived from microwave remote sensing in the Little Washita watershed, Oklahoma, for the period between June 10 - 18, 1992. Daily microwave measurements have been obtained across the watershed from the airborne ESTAR instrument. Surface soil moisture values were derived from brightness temperatures and validated using field measurements. This data set has been georeferenced in the GRASS GIS to quantify soil moisture changes during the dry-down period. Analysis of soil moisture changes and digital soils data reveals a direct relationship between changes in soil moisture and soil texture. Areas identified as loam/silt loam soils are characterized by large changes in total soil moisture and sand/fine sandy loam soils by remarkably smaller amounts of change. This gives some insight into the estimation of soil hydraulic properties using temporal soil moisture data. Coarse grained sandy soils most likely drain quickly while clayey soils, characterized by low hydraulic conductivity, retained water and later drained during the experiment. This research demonstrates that a GIS is a valuable tool to establish relationships between temporal changes in remotely sensed surface soil moisture and soil properties.