Simulation-Optimization Framework to Support Sustainable Watershed Development by Mimicking the Predevelopment Flow Regime

Abstract

The modification of land and water resources for human use alters the natural hydrologic flow regime of a downstream receiving body of water. The natural flow regime is essential for sustaining biotic structure and equilibrium within the ecosystem. Best management practices mitigate the increased storm water runoff due to increased imperviousness and are typically designed and located within a watershed to match peak and minimum flows for a small set of targeted design storms. Ecosystems are, however, affected by all the characteristics of a long-term flow regime, including the magnitude, duration, frequency, and timing of flows. A more environmentally sustainable approach for watershed development is presented based on the minimization of differences in the characteristics of the flow regime between predevelopment and postdevelopment conditions. The indicator of hydrologic alteration (IHA) is a set of 33 hydrologic indices that characterize a flow regime and, coupled with the range of variability approac...