Environmental change, catchment hydrology and the stream environment

最近的历史和预测的未来气候变暖与积雪和融化的时间和规模的变化有关，积雪融化往往提前几天到几周发生。变暖也与冰川质量损失和收缩有关。雪和冰川的这些变化导致河流流动模式和水温的变化，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有价值的冷水鱼类有害。冰川收缩减少了可供融化的冰的数量，从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，植被最终在冰川退缩暴露的地区建立和发展。这两种变化都会增加蒸发造成的水分损失，从而减少河流流量;然而，对这些变化的研究有限。虽然了解了变化的一般方向，但需要更有力的基于进程的工具来评估这些变化在具体情况下的程度。拟议研究的总体目标是提高我们对融雪模式和冰川退缩变化如何导致夏末河流流量和温度变化的理解和预测能力。这项研究将结合联合收割机实地测量、卫星遥感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，特别是布里奇河和利卢埃特河，这两条河都含有重要的冰川。研究还将集中在上彭蒂克顿溪，一个长期的研究地点在奥肯纳根山谷的高地。 研究成果将成为在目前条件下估计河流流量和温度的改进工具，这将支持渔业管理人员评估鱼类目前的生境适宜性。这些工具还可用于估计流量和温度如何因未来气候变化而变化，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.