Environmental change, catchment hydrology and the stream environment

近期历史和预估的未来气候变暖与积雪和融雪的时间和规模的变化有关，融雪有提前数天至数周发生的趋势。变暖还与冰川质量的损失和萎缩有关。雪和冰川的这些变化导致河流流量模式和水温的变化，特别是在夏末造成流量减少和温度升高。这两种变化都可能对太平洋鲑鱼等珍贵的冷水鱼类有害。冰川萎缩通过减少可供融化的冰量而影响下游的河流流量。此外，冰川退缩往往导致湖泊的形成，并最终在冰川退缩暴露的地区建立和发展植被。这两种变化都可以通过蒸发增加水分损失，从而减少成为河流流量的水量；然而，对这些变化的研究是有限的。在了解变化的一般方向的同时，还需要更健壮的基于过程的工具来评估特定情况下这些变化的大小。拟议研究的总体目标是增加我们对变化的融雪模式和冰川退缩如何导致夏末河流流量和温度变化的理解和预测能力。这项研究将结合实地测量、基于卫星遥感的数据收集以及统计分析和计算机模拟模型的使用。研究将集中在不列颠哥伦比亚省南部海岸山脉的地点，特别是桥河和利卢埃特河，这两条河都有重要的冰川。研究还将集中在上彭蒂克顿溪，这是奥肯那根山谷高地的一个长期研究地点。研究结果将改进估算当前条件下河流流量和温度的工具，这将支持渔业管理者评估当前鱼类栖息地的适宜性。这些工具还可以用来估计未来气候变化将如何导致流量和温度变化，这可以帮助资源管理者制定适应和缓解战略，以保护鲑鱼和其他冷水鱼类。

Recent historical and projected future climatic warming has been associated with changes to the timing and magnitude of snow accumulation and melt, with a tendency for snowmelt to occur days to weeks earlier. Warming has also been associated with glacier mass loss and shrinkage. These changes to snow and glaciers result in changes to river flow patterns and water temperature, in particular by causing reduced flows and higher temperatures in late summer. Both of these changes can be harmful to valued cold-water fish species such as Pacific Salmon. Glacier shrinkage influences downstream river flows by reducing the amount of ice available for melt. In addition, glacier retreat often results in formation of lakes, and vegetation eventually establishes and develops on areas exposed by glacier retreat. Both of these changes can increase water loss by evaporation, which reduces the amount that becomes river flow; however, research on these changes is limited. While the general directions of change are understood, there is a need for more robust process-based tools to evaluate the magnitudes of these changes in specific situations. The overall objective of the proposed research is to increase our understanding of and ability to predict how changing snowmelt patterns and glacier retreat will cause late-summer river flows and temperature to change. The research will combine field measurements, data collection based on remote sensing from satellites, and the use of statistical analysis and computer simulation models. Research will focus on sites in the southern Coast Mountains of British Columbia, particularly on the Bridge and Lillooet Rivers, both of which contain significant glaciers. Research will also focus on Upper Penticton Creek, a long-term research site in the highlands of the Okanagan valley. The outcomes of the research will be improved tools for estimating river flows and temperatures under current conditions, which will support the assessment of current habitat suitability for fish species by fisheries managers. The tools can also be used to estimate how flows and temperature would change as a result of fututure climate change, which can help resource managers develop strategies for adaptation and mitigation to protect salmon and other cold-water fish species.