Investigating the consistency and reliability of multiple datasets in estimating water balances in major Canadian river basins
Abstract
Given the scarcity of direct in-situ measurements, the increasing availability of various products for different water budget components makes it possible to better evaluate the water balance and its uncertainty at regional or continental scales. In this study, we utilize various remotely sensed and data assimilation based products to characterize the water balance closure of 24 major Canadian river basins of size ranging from 90,900 to 1,679,100 km2 during 2002-2013. Multiple sources of data for each water budget component, including two precipitation products (the global product WATCH Forcing Data ERA-Interim (WFDEI), and the Canadian Precipitation Analysis (CaPA)), two evapotranspiration products (MODerate Resolution Imaging Spectroradiometer (MODIS), and Global Land-surface Evaporation: the Amsterdam Methodology (GLEAM)), and one source of water storage data (the Gravity Recovery And Climate Experiment (GRACE)) from three different centres are combined through a water balance equation to estimate monthly streamflow, which is compared with observed streamflow by using percentage of bias, root mean square error and correlation coefficient to assess water balance performances. Results showed that the median values of the ensembles are generally able to capture the mean annual cycle for most of the basins except for Saskatchewan, Nelson, Churchill, and Great Bear River basins. Overall, the estimated streamflow as a residual of the water budget is underestimated in spring and winter by 6.81 and 4.68 mm/month and overestimated in summer and autumn by 2.35 and 4.19 mm/month, respectively. In particular, the combination of WFDEI, MODIS, and the equal-weighted GRACE of the three centres tends to outperform other combinations in Mackenzie and its sub-basins. Findings from this study can provide guidance to potential users regarding the reliability of different products in undertaking water balance characterization for a range of geographical regions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H51V1624W
- Keywords:
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- 1655 Water cycles;
- GLOBAL CHANGEDE: 1816 Estimation and forecasting;
- HYDROLOGYDE: 1847 Modeling;
- HYDROLOGYDE: 1855 Remote sensing;
- HYDROLOGY