Simulation of runoff-producing rainfall in the Southwest

Abstract

The southwestern United States relies heavily on limited, undependable surface water and limited groundwater resources. Further growth will require reliable estimates of current and potential surface water resources. Procedures are developed for simulating the distribution of runoff-producing rainfall in Arizona and New Mexico, which can be used during design and decision making processes for surface water and land use management. Existing event-based stochastic models are modified to describe the occurrence, and spatial and temporal distribution of rainfall events. Probability distributions for storm parameters are obtained from analysis of historical data for regional and local areas of investigation. Sequences of rainfall events are simulated using Monte Carlo techniques and potential runoff-producing events are selected to drive a deterministic watershed model. Rainfall configurations are graphically analyzed and simulated runoff from similar and dissimilar storm configurations are analyzed. Rainfall simulation was performed for locations in northeastern and southeastern Arizona and runoff simulation was tested on a wildland watershed in southeastern Arizona.