Simulation of a Semipermanent Wetland Basin in the Cottonwood Lake Area, East-Central North Dakota

Abstract

A coupled surface/subsurface hydrologic model was developed to examine the effects of climatic conditions on stage fluctuations within a semipermanent wetland located in the Prairie Pothole region of east-central North Dakota. Model calibration was accomplished using data collected from 1981 until 1996 to encompass extreme climatic conditions. Simulation results suggest that wetland inflows are dominated by runoff (36%), direct precipitation to the lake (45%) and groundwater inflows (19%), while outflow from the wetland is primarily evaporation (84%) and groundwater discharge to the underlying aquifer (16%). Modeled surface runoff produces short duration, high magnitude flows typically associated with spring thaw while modeled groundwater provides flows smaller in magnitude but longer in duration that may be increasingly important to wetland stage during extended periods of drought and flood. Despite an oversimplification of the complex groundwater component of the wetland system it was found that this modeling approach was able to predict system response over