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Hydrologic response of the Crow Wing Watershed, Minnesota, to mid-Holocene climate change
- Source :
- The Geological Society of America Bulletin. March-April, 2007, Vol. 119 Issue 3-4, p363, 14 p.
- Publication Year :
- 2007
-
Abstract
- In this study, we have integrated a suite of Holocene paleoclimatic proxies with mathematical modeling in an attempt to obtain a comprehensive picture of how watersheds respond to past climate change. A three-dimensional surface-water-groundwater model was developed to assess the effects of mid-Holocene climate change on water resources within the Crow Wing Watershed, Upper Mississippi Basin in north central Minnesota. The model was first calibrated to a 50 yr historical record of average annual surface-water discharge, monthly ground-water levels, and lake-level fluctuations. The model was able to reproduce reasonably well long-term historical records (1949-1999) of water-table and lake-level fluctuations across the watershed as well as stream discharge near the watershed outlet. The calibrated model was then used to reproduce paleo-groundwater and lake levels using climate reconstructions based on pollen-transfer functions from Williams Lake just outside the watershed. Computed declines in mid-Holocene lake levels for two lakes at opposite ends of the watershed were between 6 and 18 m. Simulated streamflow near the outlet of the watershed decreased to 70% of modern average annual discharge after ~200 yr. The area covered by wetlands for the entire watershed was reduced by ~16%. The mid-Holocene hydrologic changes indicated by these model results and corroborated by several lake-core records across the Crow Wing Watershed may serve as a useful proxy of the hydrologic response to future warm, dry climatic forecasts (ca. 2050) made by some atmospheric general-circulation models for the glaciated Midwestern United States. Keywords: paleohydrology, climate change, hydrogeology, modeling, paleolimnology.
Details
- Language :
- English
- ISSN :
- 00167606
- Volume :
- 119
- Issue :
- 3-4
- Database :
- Gale General OneFile
- Journal :
- The Geological Society of America Bulletin
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.160591467