Evaluating and predicting the resiliency of lakes

点击翻译按钮获取中文摘要

Lakes are changing in response to human activity. Evaluating and predicting lake resiliency to these changes is crucial to developing mitigation and management strategies. The proposed research program aims to develop diagnostic and prognostic tools to assess a lake's response to human impacts within a changing climate. The proposed research program will focus on lacustrine physical transport processes including internal waves, under-ice circulation, and seasonal and inter-annual evolution of thermal stratification. This, in collaboration with research partners will be extended to assess and predict water quality and ecological impacts.******Lake ecology and hence water quality is dependent on physical processes at time scales ranging from turbulence to inter-annual, and spatial scales from individual organism to basin size. Depending on local climate, the seasonal evolution of thermal stratification is typically characterized by prolonged (months) thermal stratification separated by brief periods of complete mixing (days to weeks). In a Canadian climate all of these processes are mediated by snow and ice-cover. Each lake's ecology is adapted to and dependent on the timing and frequency of these seasonal mixing events, as well as duration and quality of snow and ice-cover. However, impacts of a changing climate, sometimes combined with direct human intervention (addition of material and energy through continuous discharge or rapid dumping), can drastically change the timing and duration of mixing, stratification, and snow/ice cover periods, which can have dire implications for resident ecology and water quality. ******The proposed research combines field measurements with numerical hydrodynamic modelling to evaluate and predict lake resiliency. In this regard, field and numerical methods provide an important complement to field data that provides "ground truth" in describing how a lake system functions, as well as essential data needed to validate numerical models, which can be used for 1) quantifying mass transport, 2) process studies (isolating critical processes), and 3) predicting the future impact of human activities (accidental or managed) and/or climate warming. ******The end result of the proposed research will be an improved understanding of the circulation and transport dynamics of ice-covered and ice-free lakes and reservoirs, as well as development and application of numerical hydrodynamic models of these lakes and reservoirs. Results from targeted lakes will be generalized to enhance numerical hydrodynamic, water quality and ecological modelling capabilities.