Mathieu Monfette

Université de Montréal
M.Sc. candidate

Supervisor: Thora Martina Herrmann
Start: 2016-09-05

Project

Inland water quality and community monitoring by means of optical remote sensing data. Application in an Arctic river basin (George River, Nunavik, Canada)
Arctic rivers, such as the George River, are among the least understood and studied hydrological systems. Northern rivers drain vast regions where hydrological data are sparse and scientific understanding is limited. Here we present the preliminary results of a research program that seeks to integrate scientific approaches and traditional knowledge to advance our understanding of environment and climate change in arctic freshwater ecosystems. Our study focuses on the George River watershed (565 km length, 41 700 km²), located in Nunavik, the sub-arctic region of Northern Québec (Canada). The George River basin is home to the Inuit of Kangisuallujuaq who value the river and its watershed as the basis of their livelihood, culture and well-being. Adjusting to climate change and the significant pressure to exploit natural resources (i.e., rare earth elements (REE) mining project) within the river basin has become a major concern for the community and for researchers. To address this concern, a Science Land Camp program involving Youth, Elders and local experts was co-initiated by the community of Kangiqsualujjuaq and University researchers, to undertake a long-term biomonitoring program of the George River watershed, before the start of a Rare Earth Elements mining project. Field campaign to obtain water quality measurements were conducted during the summers 2016 and 2017, and simultaneously drived with data acquisition from space-borne remote sensing systems. Developments in optical remote sensing now make it possible to visualize processes dynamics and anthropogenic impacts over large areas. Our sampling efforts seek to establish the predictive relationships between in-situ measurements and data obtained through remote sensing, that will subsequently allow us to gain insight into changes in water quality at the watershed scale. Measurements taken along a 50 km stretch of the river included: (i) aquatic productivity (chlorophyll-A), alkalinity,…; (ii) turbidity, suspended sediment concentration (SSC), and water color, and (iii) water depth. Our preliminary results characterize the George River as having clear and soft water with neutral pH and low nutrients. These data are compared to the relatively fine scale (10 to 30 m spatial resolution) remote sensing multispectral information obtained from two distinct optical imaging satellites (i.e., Sentinel-2A’s Multispectral Instrument, and Landsat-8 Operational Land Imager). The insights gained through field measurements and remote sensing will be integrated with Kangiqsualujjuamiut knowledge to help identify the complex interactions between social-ecological change, economical development, and climate change.

Keywords

Fluvial, télédétection, suivie communautaire, qualité de l'eau