ASSESSMENT OF LONG-TERM AND RECENT GROUNDWATER LEVEL RECORDS IN WISCONSIN FROM 1917 TO 2017

This study examines the relationship between regional GL trends, aquifer sensitivity, land use, and climate variability in Wisconsin, USA. Monthly GL data were obtained from the U.S. Geological Survey (USGS) and monthly outputs of WI divisional climate data were obtained from the Midwestern Regional Climate Center (MRCC). Data were analyzed for long-term (1917-2017) and the recent short-term (2002-2017). Well records were required to span at least ten years for long-term analysis, and seven years for short-term analysis, and contain fewer than 15% omissions. Out of 20 total wells for long-term analysis, 11 are in sand and gravel, six are in the Cambrian-Ordovician aquifer (sandstone), and three are in the Silurian-Devonian aquifer (carbonates). GL trends show increasing gradients of 0.04 to 0.22ft/yr in southwest Wisconsin (climate zones 7 and 8). Preliminary short-term analysis has shown GL trending upward across much of the state.