GIS to Estimate Storm-Water Pollutant Mass Loadings

Abstract

In order to develop a monitoring program for the Santa Monica Bay, Calif., watershed, a land-use runoff model was developed using a geographic information system (GIS) coupled with an empirical runoff model. The GIS/model has simple data requirements as compared to more complex models that require routing information; and it is useful for predicting receiving-water loading on an annual basis or for single-storm events. Its approach can also be used to graphically present model results in simple and intuitive ways that provide better insight to managers and planners in evaluating pollution sources and control strategies. The GIS/model was used to locate monitoring stations in the most economical way. The model predictions can be used to improve the evaluation of best management practices to control pollutant discharges. Receiving-water pollutant contributions from point and nonpoint sources can be compared to develop more economical strategies for overall pollutant minimization.