HR: 14:10h
AN: H42I-03 INVITED     [PDF]
TI: Seasonal and spatial patterns in water quality: the importance of the geomorphic template
AU: * McKnight, D M
EM: diane.mcknight@colorado.edu
AF: INSTAAR, 1560 30th Street, Boulder, CO 80309 United States
AU: Gooseff, M
EM: michael.gooseff@utu.edu
AF: Department of Aquatic, Watershed and Earth Resources, Utah State University, Logan, UT 84332 United States
AU: Mladenov, N
EM: natalie.mladenov@colorado.edu
AF: INSTAAR, 1560 30th Street, Boulder, CO 80309 United States
AU: Hood, E
EM: eran.hood@usa.alaska.edu
AF: University of Alaska Southeast, 11120 Glacier Highway, Juneau, AK 99801 United States
AU: Williams, M
EM: mark.williams@colorado.edu
AF: INSTAAR, 1560 30th Street, Boulder, CO 80309 United States
AB: Geomorphic processes exert strong controls on the hydrologic connections between surface water bodies and the surrounding landscape. Further, geomorphic processes influence habitat characteristics and the distribution of terrestrial and aquatic biota. In a given watershed, seasonal patterns in water quality reflect changes in dominant hydrologic pathways and biogeochemical processes. The importance of geomorphic controls is evident in diverse systems. In the McMurdo Dry Valleys in Antarctica, periglacial processes result in the formation of stone pavements in streams of moderate gradient. These stone pavements provide a stable habitat for perennial algal mats. As a result, moderate gradient streams have not only abundant algal mats but also much lower nutrient concentrations than steep gradient or sandy streams, in which algal mats do not persist overwinter. In the Rocky Mountains, some watersheds contain lakes as a result of previous glaciations and others do not. In stream networks containing lakes, the growth of phytoplankton in summer influences seasonal patterns in both nutrient and dissolved organic material concentrations. The Okavango Delta, a large wetland in Botswana, is comprised of areas of permanent swamp and areas that are seasonally inundated. Because of leaching of dried vegetation by the arrival of the floodwaters in the seasonal swamp, the seasonal changes in the concentration and quality of dissolved organic material in the seasonal swamp are much greater than those in the permanent swamp where saturated conditions persist year round.
DE: 1806 Chemistry of fresh water
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2003 Fall Meeting