CGRG Bibliography of Canadian Geomorphology
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Author : Fang, X.; and Pomeroy, J.
Date : 2007.
Title : Effects of drought on Canadian Prairie wetland snowmelt hydrology.
Publication : CMOS, CGU, AMS Congress 2007. "Air, Ocean, Earth and Ice on the Rock". May 28 - June 1, 2007. St. John's Congress Centre, Newfoundland and Labrador, Canada.
Issue :
Page(s) : I11-4D1.7.
Abstract
Severe drought developed on Canadian Prairies during the period of 1999-2002. Wetlands represent an important water resource on Canadian Prairies providing water supply to farms and habitat to wildlife. The physically-based Cold Regions Hydrological Modelling platform (CRHM) was used to analyze the impacts of this recent drought on the water supply over a Canadian prairie wetland. CRHM is based on a modular, object-oriented structure in which component modules represent basin descriptions, observations, or physically-based algorithms for calculating hydrological processes such as wind redistribution of snow, snowmelt, infiltration into unsaturated frozen soils, and snowmelt runoff. To calculate the water balance of a basin, modules are linked into a purpose built model for the basin of interest. The model simulations were conducted for the watershed of wetland 109 at St. Denis NWA, Saskatchewan for the hydrological years during the drought period of 1999-2002 and the non-drought period of 2005/06. Results show that much lower precipitation, less snow accumulation, shorter snowcover duration, suppressed blowing snow sublimation, enhanced winter evaporation, and ultimately much lower runoff to wetland developed during the drought. Compared to the spring of 2006, there was only 26%, 3%, and 30% of runoff in the springs of 2000, 2001, and 2002, respectively. This is consistent with the observed snow accumulation and water levels. An analysis of the sensitivity of runoff to land cover was conducted. Summer-fallowed fields replaced stubble fields in the contributing area of the model. The results of the land use change show that runoff to the wetland increased by 36%, 6%, and 1% in the springs of 2000, 2001, and 2002, respectively, corresponding to this land cover change. These results show that springtime hydrological sensitivity to drought is strongly controlled by land cover and agricultural practice.
Bibliography of Canadian Geomorphology