ABSTRACT
Agricultural streams are often strongly altered by channel straightening and bank stabilization structures. These measures lower the streams’ ecological value and can lead to sediment transport issues. A hydrogeomorphological assessment helps identify the root causes of degradation problems and address these issues sustainably. Such an assessment, partly based on LiDAR-based digital elevation models (DEMs), was conducted on three agricultural watersheds located in Quebec (Canada), which face various issues related to fish habitat; drinking water supply and water quality. As channel mobility generally occurs at a broader scale than the scale typically used for targeted interventions, this advocates for a more comprehensive type of approach, such as the implementation of a freedom space to allow proper fluvial processes to operate at the watershed scale. Moreover, hydrological processes on the “terrestrial” portion of the watershed could play a significant role in the sediment dynamics and overall state of watercourses.
