The development and testing of a water balance model for climate impact assessment: Modeling the Sacramento Basin

Abstract

Within the next few decades, changes in global temperature and precipitation patterns caused by increasing atmospheric concentrations of carbon dioxide and other trace gases are likely to appear. At present, we are unable to evaluate the regional hydrologic impacts of such climatic changes with any certainty. Using modified water balance methods, a model of a critical hydrologic basin, the Sacramento Basin in California, is developed and tested for the purposes of investigating the effects on water availability of changes in climate. This basin was chosen because of the importance of its water supplies to agricultural and industrial productivity and because of the quality and quantity of the hydrologic data available. The water balance model is capable of reproducing both the magnitude and the timing of monthly and seasonal runoff, as well as changes in soil moisture conditions. The results suggest that the application of such models may provide considerably more information on regional hydrologic effects of climatic changes than is currently available. Such information is likely to have important ramifications for long‐range water resource planning, for agricultural water development and conservation, and for industrial water use over the next several decades.