HR: 1340h
AN: GC33A-0937    [Abstracts]
TI: Simulating the Effects of Climate and Land Use Change on Wetland Hydrology in coastal South Carolina, USA
AU: Trettin, C C
EM: ctrettin@fs.fed.us
AF: Center for Forested Wetlands Research, USDA Forest Service, 2730 Savannah Highway, Charleston, SC 29414, United States
AU: Li, C
EM: changsheng.li@unh.edu
AF: Complex Systems Research Center, EOS, University of New Hampshire, 39 College Road, Durham, NH 03824, United States
AU: * Dai, Z
EM: zdai@fs.fed.us
AF: Complex Systems Research Center, EOS, University of New Hampshire, 39 College Road, Durham, NH 03824, United States
AU: Amatya, D M
EM: damatya@fs.fed.us
AF: Center for Forested Wetlands Research, USDA Forest Service, 2730 Savannah Highway, Charleston, SC 29414, United States
AU: Sun, G
EM: gesun@ncsu.edu
AF: Southern Global Change Program, USDA Forest Service, 920 Main Campus Dr. Venture II, Suite 300, Raleigh, NC 27606, United States
AB: Hydrology controls the majority of ecosystem functions and ecological services derived from wetlands; it is also the primary regulator of carbon dynamics, which is significant because wetlands contain 20-30%\ of the terrestrial carbon. Accordingly, the ability to simulate wetland hydrology is fundamental to assessing ecosystem responses to climate change and other anthropogenic disturbances. We present the application of MikeShe to an Atlantic coastal plain watershed with long-term gauging records from the Santee Experimental Forest. The simulation model was calibrated and validated against stream outflow and water table, and evaluated by the Pearson correlation coefficient (R), and the Nash and Sutcliffe model efficiency metric (E). The E (0.72 and 0.93 for daily and monthly outflows and 0.52 for water table in a 3 year period), R (0.80, 0.98 and 0.83) and slope for the regression (0.84, 1.03 and 1.02) of observations vs. simulations showed that MikeShe can perform reasonably well to estimate the overall hydrology of this low-relief watershed (WS80). The calibrated and validated model was then used for assessing the hydrologic response of the watershed to climate changes and land use change, from forest to agriculture. The effects of altered precipitation or temperature on stream outflow and groundwater table may be significant. A simulated 10%\ decrease in precipitation decreased stream outflow 20%\ and the mean water table depth 15%\ (11cm on average within the watershed); a simulated 10%\ increase in precipitation increased stream outflow by 10%\ and mean water table depth 12%\ (8cm). A 2°C increase in mean temperature decreased stream outflow by 7%\ and water table by 6 to 22%\ (8cm on average ); this effect was primarily attributable to an increase ET. Simulated land use change from forest to agriculture caused large changes in the hydrology of watershed WS80; stream outflow increased by 29% and the mean water table was raised by 8cm.
DE: 1600 GLOBAL CHANGE
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1630 Impacts of global change (1225)
DE: 4805 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 1615, 4912)
DE: 4912 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 1615, 4805)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting