Integrating depression storages and their spatial distribution in watershed-scale hydrologic modeling

Surface depressions are important topographic characteristics for surface runoff initiation, and the spatial distribution of may further affect timing quantity reaching channels outlets. However, many hydrologic models simulate fill-spill processes depression-dominated areas in a lumped manner release outflows from to or outlets directly. As result, progressive formation contributing area (CA) dynamic contribution process not well characterized. The objective this study is improve depression-oriented modeling by incorporating influence depression storages their into simulation generation flow routing. To achieve objective, modified variable (MD-VCA) model developed catchment response during rainfall events, which employs new depressional time-area zone scheme deal with spatially distributed storages, tracks intrinsic changing patterns connected storage, simulates area-based dynamics, implements CA-based routing technique, quantifies likelihood occurrence outlet CA contributions using joint probability associated distribution. performance MD-VCA was evaluated through application watershed Prairie Pothole Region North Dakota. Simulation results demonstrated that able threshold-controlled overland dynamics under different conditions, it effectively revealed influences on propagation processes.