NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, permafrost, arctic lakes, climate change, hydrology, remote sensing

Objective(s): To better understand the spatial and temporal representativity and variability of the optical (color), chemical (organic and inorganic matter and metals) and biological (gross primary production and chlorophyll) properties of very different lakes some how related to permafrost thaw events, either in a distant or recent past.

Project Description: This licence has been issued for the scientific research application No. 5639. The goal of this research project is to better understand the characteristics of various different lakes, how their characteristics vary, as well as their potential relation to permafrost thaw events in the recent or distant past. The frequency of occurrence across space and time as well as the variability of: 1) optical (color); 2) chemical (organic and inorganic matter and metals); 3) biological (gross primary production and chlorophyll) properties of different lakes will be studied to accomplish this. This research project also has the goal of better understanding the biophysical context where these characteristics develop, not only in terms of the geological/lithological settings (type of soils), but also regarding geomorphological features (landforms and evolution) and terrestrial ecosystems. The expected outcomes relate to the production a remote sensing algorithm able to track changes in important optically active parameters of lakes (dissolved organic matter, turbidity and chlorophyll) in space and time and also high resolution maps related to the distribution of vegetation in the lake basins along the Dempster Highway. The data and analysis that will be performed will also feed scientific publications that will be readily available and sent to the communities, and will contribute to a better understanding of climate change on the permafrost region, including lake waters. The study will be carried out through field sampling that will allows for remote sensing data calibration. The research team aims to measure: 1) water properties using a multiparameter sensor; 2) spectral properties of water and vegetation. The data will be used for analysing satellite images, spatial and temporal dynamics of key components of lake water (such as chlorophyll-a), dissolved organic matter, transparency, turbidity and others. Analysis of the vegetation will be important for the characterization of the lake marginal areas. No sampling will be conducted. For the multiparameter probing the research team will be using a very small inflatable boat (about 2m), which will be used for reaching a location away from lake margin influence. For the spectral measurements a hand-held spectrometer will be used by pointing to the water and vegetation at about 20 cm distance. The multiparametric probe will allow the acquisition of variables such as conductivity, dissolved oxygen, temperature, pH, redox potential, dissolved organic matter and chlorophyl in depth along the lakes water columns. The data will be further processed and used for linear, non-linear and machine learning regressions along with satellite imagery reflectance that will allow for the spatial distribution of these variables in wide regional sectors, as well as understand how they vary in time. Sentinel-2, PlanetScope and Landsat satellites imagery will be used for these purposes. The project in the Inuvialuit Settlement Region and Northwest Territories will be conducted over a short period of time – 8 days, with 6 days in the field, due to high costs. The procedures recommended by the Aurora Research Institute are considered. In addition, the research team has been collaborating with the Tuktoyaktuk Hamlet since 2018 with ongoing projects and activities. For this project, the team is also informing the Beaufort-Delta Region Department of Lands about our goals. The team is also contacting the Inuvialuit Regional Corporation. Before beginning the field work the research team will contact Community representatives in Tuktoyaktuk and Inuvik with three objectives: letting them know about the arrival and leaving dates, as well as the goals and activities, as well as explaining the project and interest in collaborating. All data and results will be made available for community use. The fieldwork for this study will be conducted from August 2, 2023 to December 31, 2023.