NWT RESEARCH DATABASE

Tags: physical sciences, permafrost, hydrology, prediction models, ecology, tundra ecosystems, permafrost thaw

Objective(s): To understand and predict the impacts of permafrost thaw on water resources and ecosystem.

Project Description: Understanding the integrated eco-hydrological behaviour of ecosystems in the context of thawing permafrost is a major challenge. To meet this, the research team will measure the present surface and near-surface water supplies and their inter-annual variability assuming a condition of no permafrost thaw. The team will also develop new knowledge on the eco-hydrology of the major ecosystems (i.e. bogs, fens, peat plateaus) needed to develop new science-based tools to predict the future supply of water for the next 50 years. The specific scientific objectives are to: 1) develop fundamental knowledge of the major ecosystems and estimate the amount of water present. The watershed responses to changes in permafrost regime and the rate and trajectory of such changes will also be examined; 2) develop and test a new suite of eco-hydrological predictive tools for simulating the responses of ecosystems to permafrost thaw and the rate and pattern of ecosystem change; and, 3) apply the new integrated eco-hydrological models to predict terrestrial and aquatic ecosystem responses to permafrost thaw extending over the next half-century. The research team will examine permafrost, ecology, hydrology and their interactions. The present condition of each of these Earth system components is determined by outside factors including prevailing climate, disturbance and geological setting. Further, these factors display complex feed backs and interactions that influence ecosystem function and services. To understand these complexities, the research team will begin by evaluating and integrating state-of-the-art models to identify the knowledge gaps. This knowledge will be used to drive the field and laboratory research, with integration occurring annually and in a final culminating report of this project. The ultimate goal of this project is to predict the stream flow regime over the next 50 years, including the total annual flow, peak flow timing and volume, baseflow amount, and frequency of high flow and low flow events. The basic frame work is similar to the standard approach used in non-permafrost regions of Canada, where a large-scale, distributed hydrological model is calibrated and validated under the present and historical conditions and subsequently used with a model of future climate. The unique challenge in the study region is that the rapid thawing of permafrost can potentially cause a major change in the hydrological characteristics of river basins. Therefore, the conditions within each grid cell of the hydrological model need to be updated over the course of the 50-year simulation, which requires the prediction of permafrost thawing and the subsequent response of landscape (e.g. forested areas turning into wetlands). To implement these processes in a grid-based hydrological model, the research team will set up several Northern Ecosystem Soil Temperature (NEST) models within each grid cell. NEST is a one-dimensional energy and water transfer model specifically designed to simulate the evolution of permafrost under different land covers. Multiple NEST models will represent different landcover types within the grid cell (e.g. bog, fen, peat plateau), and a new algorithm will be developed to simulate the lateral exchange of water and energy among the NEST models. NEST models will be embedded within a hydrological model, which provides the hydrological boundary condition for NEST, while NEST provides the information on permafrost and land cover distribution to the hydrological model. The coupled model development will be conducted using the data from Scotty Creek Basin. Once the model is complete, it will be tested for the Scotty Creek Basin and the adjacent Jean-Marie Creek Basin, where long term climate and stream flow data, as well as spatial information (e.g. distribution of permafrost) are available from the analysis of archived aerial photographs and satellite images. Engagement of communities is a priority for the purpose of 2-way knowledge flow and education of researchers and communities alike. Guidance of project will be sought through public consultation with community groups at Jean-Marie and Fort Simpson. The research team continue to liaise with the Liddli Kue and Jean-Marie First Nations. Annual reports to the Aurora Research Institute, and publications will be sent to the communities each year. The Principal Investigator also visits as many of the band offices and government agencies when in the Fort Simpson region. Dissemination and outreach is enhanced through the 10-year (2010-2020) Partnership Agreement between Laurier and the Government of the Northwest Territories. The Partnership appointed a community Liaison to facilitate two-way communication with communities. The fieldwork for this study will be conducted from March 15, 2016 to August 31, 2016.