Long‐term water budget imbalances and error sources for cold region drainage basins

• Published in: Hydrological processes Vol. 29; no. 9; pp. 2125 - 2136
• Main Authors: Wang, Shusen, Huang, Jianliang, Yang, Daqing, Pavlic, Goran, Li, Junhua
• Format: Journal Article
• Language: English
• Published: Chichester Wiley 30.04.2015; Wiley Subscription Services, Inc
• Subjects: Assessments; Basins; Budgeting; Canada; Closures; Cold; cold region; Cold regions; data collection; Drainage; Drainage basins; EALCO model; Errors; Evaporation; Evapotranspiration; GRACE (experiment); GRACE observation; GRACE satellite; Hydrologic processes; Hydrology; Quality assurance; quality control; River basins; Satellite observation; Snow; Stream discharge; Stream flow; surface water; Trends; uncertainty; water balance; Water budget; Water resources; Water storage; watersheds; Canada
• ISSN: 0885-6087; 1099-1085
• DOI: 10.1002/hyp.10343

This study assessed the long‐term (1979–2008) water budget closures for 19 large cold region drainage basins in Canada using recently developed datasets for precipitation (P), land surface evapotranspiration and water surface evaporation, and observed streamflow. Total water storage (TWS) trends from the GRACE satellite observations were also used to assist the assessment. The objectives are to quantify the magnitudes and spatial patterns of the water budget imbalance (ε) and its source of errors for these cold region basins. Results showed that the water budget was closed within 10% of the P on average for all the basins. The ε showed a general pattern of positive values in the south and negative values in the north and mountainous regions over the country. Basins with large ε values were mostly found in the north. Uncertainties in the water budget variables, particularly P, were found to play a major role in the ε. Significant trends in TWS were found over 11 basins, which accounted for 31% of their ε on average. Improvements in the observation network, data quality assurance, and spatial models for P are critical for further improving the water budget closure for the cold region drainage basins. © 2014 Her Majesty the Queen in Right of Canada. Hydrological Processes. © John Wiley & Sons, Ltd.