INRS-ETE/Institut National de la Recherche Scientifique - Eau Terre Environnement, 490 rue de la Couronne, G1K 9A9, Quebec City, Québec, Canada.
Département de phytologie, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, 2425 rue de l'Agriculture, G1V 0A6, Quebec City Québec, Canada.
J Environ Manage. 2019 Mar 15;234:448-457. doi: 10.1016/j.jenvman.2018.12.095. Epub 2019 Jan 11.
Conversion of wetlands into other land covers such as cropland or urban area can affect watershed hydrology. The main objective of this work was to quantify the impact of land cover changes, especially those for wetlands, on low flow support and high flow attenuation, through a sub-watershed analysis of the St. Charles River, Quebec, Canada. 1978 and 2014 land cover scenarios, depicting a decrease in wetland areas of 15% at the watershed scale, were integrated into the hydrological modelling platform PHYSITEL/HYDROTEL. The most sensitive model parameters were automatically calibrated at the sub-watershed scale using the dynamically dimensioned search (DDS) algorithm. Pairs of simulations (with and without wetlands) were generated and model outputs were compared to illustrate the differences between the hydrological services provided by the wetlands of the 1978 land cover scenario and those provided by the wetlands of the 2014 land cover scenario. Results showed that low flow support at the outlet of the watershed, in scenarios with wetlands, compared to without wetland, would have increased from 2 to 14% in the 1978 land cover scenario (depending on flow indicator) and from 3 to 20% given the 2014 land cover scenario, whereas high flow attenuation would have been reduced from 15-26% to 16-20%, respectively. Results showed that the effect of wetland change was different between sub-watersheds, but demonstrated that the loss of wetland areas generally leads to a loss of hydrological services and highlighted the need for wetland conservation programs and restoration actions.
湿地等土地覆盖类型向耕地或城市用地的转变会影响流域水文。本研究的主要目的是通过对加拿大魁北克省圣查尔斯河流域的子流域分析，量化土地覆盖变化（尤其是湿地）对枯水流量支撑和洪水衰减的影响。1978 年和 2014 年的土地覆盖情景，描述了流域尺度上湿地面积减少了 15%，被整合到水文建模平台 PHYSITEL/HYDROTEL 中。最敏感的模型参数使用动态维搜索（DDS）算法在子流域尺度上自动校准。生成了一对模拟（有湿地和无湿地），并比较了模型输出，以说明 1978 年土地覆盖情景下湿地提供的水文服务与 2014 年土地覆盖情景下湿地提供的水文服务之间的差异。结果表明，与无湿地相比，有湿地的流域出口枯水流量支撑在 1978 年土地覆盖情景下将增加 2%至 14%（取决于流量指标），在 2014 年土地覆盖情景下将增加 3%至 20%，而洪水衰减将减少 15%-26%至 16%-20%。结果表明，湿地变化的影响在子流域之间存在差异，但表明湿地面积的减少通常会导致水文服务的丧失，并强调了保护湿地的必要性和进行湿地恢复的重要性。
