Factors affecting river turbidity in a degrading permafrost environment : the Tasiapik River, Umiujaq (Nunavik)

• Main Authors: Manseau, Frédéric, Bhiry, Najat, Molson, John W. H. (John William H.), Cloutier, Danielle
• Format: Other/Unknown Material
• Language: English
• Published: Canadian Science Publishing 2022
• Subjects: River turbidity; Meteorological conditions; Nunavik; Permafrost degradation; Turbidité des rivières; Conditions météorologiques; Dégradation du pergélisol; Cours d'eau > Québec (Province) > Umiujaq; Turbidité; Pergélisols; Umiujaq; Arctique*; permafrost; subarctique*; Thermokarst; pergélisol
• Online Access: https://hdl.handle.net/20.500.11794/106503; https://doi.org/10.1139/AS-2021-0036

This study focuses on spatiotemporal changes in water turbidity in relation to permafrost to document the impact of meteorological conditions and water flow on hydro-sedimentary processes in northern regions. Starting in June of 2019, water turbidity data were collected at six sites along the Tasiapik River (Nunavik). A statistical analysis was completed based on records of water turbidity, precipitation, water flow, and air temperature. Our results show a significant correlation between air temperatures and turbidity, with a correlation of up to r = 0.59. These correlations depend on the location of the site along the river and the time of the study period (June–October 2019). The flow rate was the primary factor that caused variations in the turbidity of the Tasiapik River. Our results showed that following an increase in flow rate, there was an almost simultaneous increase in turbidity due to erosion of the banks. The duration and intensity of precipitation events are also important factors affecting the process of sediment transport. Even though meteorological conditions play an important role in turbidity variation, other characteristics of the site such as the topography and the existence of thermokarst lakes are additional factors that influence the dynamics of sediment transport in the Tasiapik River. Les travaux menés en Arctique et Subarctique démontrent une accélération de la dégradation du pergélisol durant les dernières décennies, provoquant des tassements importants du sol et par le fait même, un accroissement du fluage d’eau chargée de sédiments vers les lacs et les rivières. Cette étude vise à mieux comprendre la variation spatio-temporelle de la turbidité fluviale en contexte périglaciaire dans le but de faire avancer les connaissances sur les impacts des conditions météorologiques et du débit sur les processus hydrosédimentaires des régions nordiques. Des données de turbidité de l’eau de la rivière Tasiapik, située à 5 km à l’est du village d’Umiujaq (Nunavik), ont été enregistrées de juin à ...