Climate change impact on the hydrological functioning of mountain lakes: a conceptual framework

Mountain lakes are distinctive water bodies that attract the great attention of researchers. They not only serve as a crucial water resource for the inhabitants of the upland regions but also as an important destination for millions of tourists who are attracted by the beauty of these water bodies. With the increasing concern about global warming, mountain lakes are experiencing changes in their hydrological processes and meanwhile can act as reflectors of those changes. Specifically, due to the fragility of these water bodies, understanding the consequences is significant as it can help to find out whether climate change causes degradations in lake hydrological functioning. The interactions of hydrological processes in mountain lakes with external drivers are usually hard to explain explicitly owing to their complexity. To deal with that problem, scholars tend to use conceptual frameworks, which help to reveal the dependence of a lake on particular hydrologic factors. To identify factors influencing lake hydrological function and their sensitivity to changing climate, a literature analysis was undertaken. The focus was on the Canadian Rocky Mountains where 5155 water bodies were identified using GIS. The main literature sources used to identify factors influencing lake hydrologic function were peer-reviewed articles and books. In total, 10 natural drivers critical for lake hydrological function and 2 main reflectors of climate change impacts on mountain lakes as well as 38 additional sub-factors that characterize each of the factors and reflectors, were identified. Based on that, a conceptual framework for mountain lake hydrological functioning was developed. The major problem that affected the thorough testing of the conceptual framework was a limited number of observations across lakes in the research area. Nevertheless, the conceptual framework is flexible and might be tested across many mountainous regions worldwide that experience climatic changes. Such an opportunity can be realized through the use of quantitative statistical techniques available for large datasets. Overall, the conducted research stresses the problem of a poor degree of hydrological exploration of lakes in mountain regions and presents a useful approach to represent complex interactions of natural drivers and intra-lake processes under rising temperatures