ABSTRACT

This study investigates the uncertainty in hydroclimatic modelling chain components on future changes in potential evapotranspiration, specially on low flows, at the watershed scale. A large domain covering 2080 watersheds located in Canada, the United States and Mexico is studied. The outputs from eight global climate models are post-processed using two methods to produce climate scenarios that drive 10 temperature- and radiation-based potential evapotranspiration (PET) formulas and three lumped conceptual hydrological models, under representative concentration pathways (RCP) 4.5 and 8.5 and for the future periods 2041–2070 and 2071–2100. All simulated results show an increase in PET and a decrease in low flows, computed through three statistical metrics. Based on the results, we advise the use of multiple hydrological model–PET formula combinations when investigating the impact of climate change on low flows. This study provides an assessment of the contribution of potential evapotranspiration formulas to uncertainty throughout the modelling chain.

摘要

这项研究调查了在分水岭规模上，潜在的蒸散量，特别是低流量的潜在蒸散量未来变化的水文气候模型链组成部分的不确定性。研究了覆盖加拿大，美国和墨西哥的2080个流域的大域。使用两种方法对八种全球气候模型的输出进行后处理，以产生具有代表性的集中路径（RCP）4.5和8.5下驱动基于温度和辐射的潜在蒸散量（PET）公式和三种集总概念水文模型的气候方案。未来的2041-2070和2071-2100。所有模拟结果均显示通过三个统计指标计算得出的PET升高和低流量降低。根据结果​​，在调查气候变化对低流量的影响时，我们建议使用多种水文模型-PET公式组合。这项研究对整个模型链中潜在蒸散量公式对不确定性的贡献进行了评估。