Sensitivity of groundwater/lake systems in the Upper Mississippi River basin, Wisconsin, USA, to possible effects of climate change

The Trout Lake basin, located in the Upper Mississippi River basin in Wisco nsin, contains many lakes that are connected to the groundwater system. The relative proportion of groundwater inflow for any given lake is a function of its spatial position in the regional flow system. The water and chemica l budgets of these lakes are also influenced by temporal fluctuations in pr ecipitation and groundwater recharge. The dynamic interchange between groun dwater and surface water in the Trout Lake basin was evaluated with the hel p of a three-dimensional numerical model of the groundwater flow system. Th e sensitivity of the hydrological system to the possible effects of global climate change were simulated by introducing changes in both precipitation and groundwater recharge. Results show that the hydrological budget of some lakes would be significantly altered; changes in lake level are predicted to be more pronounced for lakes that are located topographically high in th e watershed.