Department of Geography and Planning, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Integr Environ Assess Manag. 2013 Jul;9(3):370-9. doi: 10.1002/ieam.1332. Epub 2012 Oct 17.
Recent years have witnessed an increase in the use of watershed-based cumulative effects assessment (WCEA) in Canada; however, several challenges remain regarding its effective implementation and execution. Fundamental to WCEA is the establishment of linkages between environmental stressors and particular and measurable components of the aquatic environment. Dynamic and often synergistic relationships between the multiple physicochemical stressors in the landscape can affect water quantity, quality, and the health of aquatic species. Essential decisions must be made about what to measure to characterize both stressors and aquatic effects, what scale is appropriate for measurement, and to what the measurements should be referenced. This review presents lessons learned from case studies conducted in 6 different watersheds across Canada, each focused on advancing the science behind WCEA, but with varied objectives and approaches. Issues of scale, selection of aquatic environmental components or indicators for assessment, and reference conditions were compared and contrasted to highlight common challenges that can affect the implementation and outcome of a WCEA. The lack of long-term monitoring data and data inconsistencies were identified as frequently limiting factors for the advancement of WCEA science and the application of WCEA. Recommendations were made for developing a comprehensive and integrated methodology for WCEA in Canada.
近年来，加拿大越来越多地使用基于流域的累积效应评估（WCEA）；然而，在其有效实施和执行方面仍存在一些挑战。WCEA 的基础是在环境胁迫因子与特定的、可测量的水生环境组件之间建立联系。景观中多种物理化学胁迫因子之间的动态和协同关系会影响水量、水质和水生物种的健康。必须做出重要决策，即确定要测量哪些内容来描述胁迫因子和水生效应，测量的适当尺度，以及应参考哪些测量值。本综述介绍了在加拿大 6 个不同流域进行的案例研究中获得的经验教训，每个案例都侧重于推进 WCEA 背后的科学，但目标和方法各不相同。对尺度问题、评估中水生环境组件或指标的选择以及基准条件进行了比较和对比，以突出可能影响 WCEA 实施和结果的共同挑战。缺乏长期监测数据和数据不一致被确定为经常限制 WCEA 科学发展和 WCEA 应用的因素。为制定加拿大 WCEA 的综合一体化方法提出了建议。
