Potential Future Developments in Soil Moisture Budget Models for Humid Regions in Canada

Abstract

The concept of the daily soil water budget was examined. A number of budgets which fit this class of models were reviewed, but particular emphasis was given to the Versatile Soil Moisture Budget (Baier and Robertson, 1966). The strengths and weaknesses of currently available models of this type were discussed. The most significant weakness is the failure to consider excess soil water in many of these models. It is recommended that the essential components in soil water budget models, which make them applicable to a broad range of soils and climates, should account for (a) soil water retention characteristics, (b) water table depth, (c) infiltration and drainage rates, and (d) snow cover. Submodels for these components from a number of currently available budget type models are discussed, and some modifications are proposed. Some field research requirements are also identified. The development of an integrated soil water budget, with submodels for all of the above components is recommended, but each new submodel should maintain the same degree of simplicity in calculations and data requirements as is found in the original models of this type.