Harlan L. McKim

REMOTE SENSING OF SOIL MOISTURE

BACKGROUND The U.S. Army Corps of Engineers requires accurate hydrologic forecasts when it performs emergency operations during potential or actual flooding situations. These forecasts also include the prediction and assessment of drought conditions. Current hydrometeorological data bases and techniques for interactive data usage are limited in providing a reliable real—time hydrologic forecast capability. Several factors related to climate, frozen ground, and regional soil moisture combine to make hydrologic forecasting difficult. Hydrologic models are normally designed to use point measurements of precipitation and the water equivalent of snow cover as indices of actual areal mean values. Synoptic measurements of the occurrence of frozen ground and soil moisture are practically nonexistent.