ABSTRACT

This study generated a water yield dataset for Canada for 1979–2016 by subtracting the land surface evapotranspiration (ET) and water surface evaporation (E0) from precipitation (P). The dataset was validated in Budyko space and compared with streamflow (Q) before the spatial variability and trends were analysed. Results indicate (1) uncertainties of the dataset are generally small; (2) despite the asynchronous inter-annual change, annual water yield varies in a similar temporal pattern to Q; (3) annual water yield varies dramatically across Canada, ranging from about zero on the Canadian Prairies to over 2500 mm on the West Coast; and (4) annual water yield shows no significant changes over the study period in the vast majority (82.4%) of Canada’s landmass. The most significant increasing trend appears in South Central Canada, attributed to increasing P. The most significant decreasing trend appears in Northeast Canada and the Southern Montane Cordillera, attributed to decreasing P and increasing ET.

摘要

本研究通过从降水 (P) 中减去地表蒸散量 (ET) 和水面蒸发量 (E0)，生成了加拿大 1979-2016 年的产水量数据集。在分析空间变异性和趋势之前，该数据集在 Budyko 空间中进行了验证并与水流 (Q) 进行了比较。结果表明（1）数据集的不确定性普遍较小；(2) 尽管年际变化不同步，但年产水量的变化与 Q 相似；(3) 加拿大各地的年产水量变化很大，从加拿大大草原的约零到西海岸的超过 2500 毫米；(4) 在研究期间，加拿大大部分 (82.4%) 陆地的年产水量没有显着变化。最显着的增长趋势出现在加拿大中南部，