Caroline Coch

Supervisor: Prof. Dr. Hugues Lantuit (AWI)

Project: Hydrology and related organic carbon and nutrient dynamics in small Arctic catchments: A case study on Herschel Island, Yukon Territory, Canada

Coastal ecosystems in the Arctic are being affected by climate change leading to permafrost thaw, to a shifting streamflow regime and to changing fluxes of freshwater and sediment to the Arctic Ocean. Water and sediment fluxes of the great Arctic rivers have been focus of numerous investigations as they cover 53% of the Arctic Ocean’s drainage basin. Small catchments are yet widespread and could contribute large amounts of sediment to the nearshore zone. Streamflow and sediment transport is being monitored continuously only at a few sites constraining the understanding regarding water quality and nutrient availability. This project is addresses this issue by investigating streamflow and sediment dynamics of two adjacent catchments on Herschel Island in the western Canadian Arctic.

This PhD project uses data from an extensive monitoring carried out between 2014 and 2016, including discharge recordings, climate data as well as sampling of river and soil water for suspended sediment and hydrochemistry. By comparing the two adjacent watersheds on Herschel Island, sediment sources and controls of its mobilization are going to be investigated. The aim is to upscale the results to the circumpolar region using existing data sets and remote sensing data.