Date of Award
Master of Science (MS)
Quantifying the spatial and temporal dynamics between groundwater recharge, discharge, and wetlands is a necessary step to develop effective water management strategies. Wetlands in the northern Great Plains play a role in flood control, water supply, and regional ecology. The water budget of a wetland in the northern prairies is often an unequal balance between moisture input and output in which the permanence of a wetland depends on its groundwater budget. Identifying and quantifying groundwater recharge and discharge zones has applications in predicting the spatial and temporal distribution of wetlands.
The current work involved the application of a groundwater model to the watershed of the North Branch of the Turtle River in Nelson County, North Dakota. The model identified the spatial distribution of recharge and discharge zones by estimating the local configuration of the water table. Model input parameters were developed using geographic information systems (GIS). The model was modified to integrate a statistical component to spatially correlate the modeled configuration of the water table with observed water table conditions. The statistical package compared the model output arrays indicating shallow water table with the spatial distribution of observed wetlands and hydric soils. Within the watershed, recharge and discharge zones were mapped, the configuration of the water table was estimated, and areas with a shallow water table identified. Model output was found to be strongly controlled by the initial topographic profile of the landscape. The magnitude of groundwater flux was considered less reliable than the pattern of flux due to the difficulty in accurately quantifying and discretizing the physical parameters that control the rate of groundwater movement. The model and methods presented provide a means to model the groundwater hydrology of prairie pothole wetlands.
Laveau, Christopher D., "Assessing recharge and discharge across the prairie pothole landscape: application of spatial hydrological data and statistical analysis in a groundwater flow model" (2005). Theses and Dissertations. 173.