A process-based, distributed hydrologic model based on a large-scale method for surface–subsurface coupling

摘要: Abstract Process-based watershed models are useful tools for understanding the impacts of natural and anthropogenic influences on water resources predicting solute fluxes exported from watersheds to receiving bodies. The applicability process-based hydrologic has been previously limited small catchments short time frames. Computational demands, especially solution three-dimensional subsurface flow domain, continue pose significant constraints. This paper documents mathematical development, numerical testing initial application a new distributed model PAWS (Process-based Adaptive Watershed Simulator). solves governing equations major processes efficiently so that large scale applications become relevant. evaluates integrated response surface–subsurface system using novel non-iterative method couples runoff groundwater vadose zone approximating 3D Richards equation. is computationally efficient produces physically consistent solutions. All components have independently verified analytical solutions experimental data where applicable. applied medium-sized in Michigan (1169 km2) achieving high performance metrics terms streamflow prediction at two gages during calibration verification periods. uses public databases as input possesses full capability interact with GIS datasets. Future papers will describe other development fate transport modules.