Evaluation of Deterministic Models for Near Surface Soil Moisture Prediction

Demand for predicting field work conditions or off-road trafficability comes from agricultural, civil and military sectors. The spatial and temporal resolution of predictions is dependent upon application. The objective of the Bristol Off-Road Trafficability Scheme (BORTS) is to develop an operational system to predict off-road trafficability on a sq km scale for application to route management problems. The system design allows only the use of readily available data and highlights user friendliness as an important facet of the software technology. This new predictive technology is based on well established physical hydrological and evaporational processes along with a newly developed soil strength-soil moisture physical relationship. The Variable Source Simulator 2 (VSAS2) is available for use within the scheme. A route management scheme demonstrates the utility of the scheme and allows initial comparisons between the BORTS and the established U.S. Corps of Engineers system for predicting soil moisture and soil strength (SMSP model). This report describes the system development, use of the system, limitations, initial comparisons with the SMSP model and future development. The computer program was written in FORTRAN 77 and is listed in the appendices along with a code glossary. Great Britain.