Incorporating Antecedent Soil Moisture into Streamflow Forecasting within the North Platte River Basin, Wyoming

A study of incorporating soil moisture into forecasting streamflow volumes within the Wyoming North Platte River Basin is presented. Current NRCS forecasting methods are replicated and a comparison is drawn between current NRCS forecasts and the proposed forecasting methods. Current predictors used in regression based streamflow forecasting are precipitation, antecedent streamflow and snow water equivalent from SNOTEL (snow telemetry) sites. Proposed methods include extending the forecast period and adding soil moisture as a predictor variable. An expert system is utilized to segregate data based on antecedent soil moisture conditions. Correlation techniques combined with principal component analysis and stepwise regression are applied to determine ideal predictor locations and to generate validation statistics that illustrate improved forecasting ability through the implementation of antecedent soil moisture as a predictor variable.