HR: 0800h
AN: H11F-0378    [Abstracts]
TI: Global change and drought severity in the Battle River Basin, Alberta
AU: * Byrne, J
EM: byrne@uleth.ca
AF: University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K 3M4 Canada
AU: Kienzle, S
EM: stefan.kienzle@uleth.ca
AF: University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K 3M4 Canada
AU: Sauchyn, D
EM: sauchyn@regina.ca
AF: Prairie Adaptation Research Collaborative, 150 - 10 Research Drive University of Regina, Regina, SK S4S 7J7 Canada
AB: The Battle River basin is a prairie watershed with headwaters in the central Alberta Parkland region immediately east of the Rocky Mountain foothills. The watershed has low relief - mean slope of about 1.5% - typical for a prairie landscape. Most streamflow originates from spring snowmelt. In years with high snowmelt runoff, the channel wetlands are extensive and enhance runoff from summer showers. In years of low snowmelt runoff, the wetlands are of modest scale, and the rate of runoff from summer showers decline rapidly as the season advances and the wetlands shrink or disappear. Upland wetlands, also called sloughs or potholes, likely contribute very modest quantities of water to the regional groundwater system that interacts with the Battle River. The Battle has suffered a severe climatic and hydrologic drought since the year 2000. The objective herein is to define the relative severity of the drought in 2000-04 in the upper Battle River watershed. Dendrochronology data indicated the drought was one of the worst in the past several centuries. Frequency analyses indicated the summer low flow experienced in 2002 was stochastically a 1:217 year event. The average Palmer Drought Severity Index (PSDI) over the entire basin in July 2002 is at an historical extreme. Land use changes are likely adversely affecting runoff. Climate change is likely affecting hydrology, including timing and volumes of the spring peak flow and summer runoff. Water licenses have increased significantly over the past years and certainly contribute to the cumulative effects resulting in reduced streamflow, particularly in the summer months. Water authorities must re-examine the assumptions for engineering design and water allocation in the basin given the changing climate and hydrology regimes.
DE: 1719 Hydrology
DE: 1812 Drought
DE: 1884 Water supply
DE: 1600 GLOBAL CHANGE (New category)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting