GEOSCAN, résultats de la recherche


TitreEstimation of the water budget for major canadian river basins
AuteurWang, S; Huang, J; Li, J; Rivera, A; Russell, H
Source H21F-1227, 2012.
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20120235
ÉditeurAmerican Geophysical Union
RéunionAmerican Geophysical Union, Fall Meeting; San Francisco; US; décembre 3-7, 2012
Mediapapier; en ligne; numérique
ProvinceColombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon; Nunavut
SNRC1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65; 66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560
Sujetseau souterraine; bassins; budget hydrologique; réseaux hydrographiques; drainage; effets climatiques; télédétection; précipitation; Nature et environnement
ProgrammeAquifer Assessment & support to mapping, Géoscience des eaux souterraines
Résumé(disponible en anglais seulement)
Understanding regional water budgets is essential in water resources management, particularly for irrigation planning, drought, flood and pollution control, drainage system design, and climate modelling. A water budget for a drainage basin is needed to determine the magnitude of the impacts of climate change and anthropogenic disturbances on terrestrial water cycle and to evaluate possible mitigation actions. In this study, the monthly and 30-year (1979-2008) average water budgets were calculated for large Canadian river basins with an area > 90,000 km2. The total area studied takes about 58% of the entire Canadian landmass. The datasets used include two gridded precipitation products based on measurement, the land surface evapotranspiration product derived from the EALCO model, the river discharge measured from hydrometric stations, and the total water (surface water+groundwater) storage anomaly derived from GRACE satellite observations. These datasets are deemed as the best-available long-term national scale datasets that meet the requirement of this study. Our objectives are to characterise the spatial and temporal variations of water budget across the vast Canadian landmass and to answer the questions of (1) how well can we close the water budget at both long-term and monthly time scales for the major Canadian river basins and (2) which component(s) of the water budget (i.e., precipitation, evapotranspiration, river discharge, or total water storage change) and in which season and which region contribute the main error source to the water budget imbalance? We also examined the decadal change in total water storage in the major Canadian river basins and quantified the bias in evapotranspiration estimation by using the widely-accepted surface water budget approach. Our results show that the national scale water budget imbalance is very close to 0 (-0.2 mm year-1) due to the offset of positive and negative imbalances among the studies basins. Basins with positive imbalances were located mostly in the south and basins with negative imbalances were more commonly located in the north. The mean absolute annual water budget imbalance of river basins studied is 49.1 mm year-1, or 9.7% of the mean annual precipitation. The mean absolute monthly water budget imbalance is 12.1 mm month-1, or 2.5% of the mean annual precipitation. The basins of the Cordillera showed large negative trend in the total water storage over the past decade, consistent with the observations of glacier and snow cover shrinkage, permafrost degradation, and river discharge increase. Different error source was identified with different river basins in different seasons. The results will contribute to a reduction in uncertainties and a better understanding of the water cycles and water resources across the country.