Groundwater divides and surface-water divides do not always coincide, and groundwater divides are not as easy to detect as surface-water divides. Groundwater divides are also dynamic, moving in response to environmental and anthropogenic stresses. This study will investigate how different hydrological stresses can change the size and shape of the study basin and whether the stresses together mitigate or intensify the basin’s response. This study looks at three factors that may affect the size and shape of the Wolf River basin: annual precipitation, soil permeability, and the presence of high-capacity wells. This study examined four groundwater basins that represent the groundwater contributing to the baseflow at the stream-flow gauge at Langlade, on the Wolf River in northeastern Wisconsin. The study consisted of two wet years (1985 and 2015) and two dry years (1989 and 2008); the two different time periods represent before and after extensive use of high-capacity wells, pre-1990 and post-2000. The study found an overall lowering of the groundwater elevation, attributed to the hydrological stresses created by both decreases in precipitation and increases in the number of high-capacity wells in the area. The lowering of the water table allowed groundwater flow to follow bedrock topography rather than surface topography leading to increases in the groundwater basin’s area. This study highlights that the effects of one hydrological stress (groundwater pumping) can be amplified by another hydrological stress (decreased annual precipitation), resulting in similar numbers of wells having a significantly greater effect on groundwater in dry years than in wet years. This knowledge can help water-resource managers predict basin changes in similar basins.
Borchardt, Susan A.
"Variation of Groundwater Divides during Wet and Dry Years in the Wolf River Basin, Northeastern Wisconsin,"
International Journal of Geospatial and Environmental Research: Vol. 5
, Article 4.
Available at: https://dc.uwm.edu/ijger/vol5/iss1/4