Author(s): Arnaud Weber; Knut Alfredsen; Morten Stickler; Giovanni De Cesare

Linked Author(s): Knut Alfredsen, Morten Stickler

Keywords: LiDAR bathymetry; River-scale modelling; Holistic approach; Hydropeaking; Fish habitat

Abstract: In the field of hydraulic engineering the management of water resources in regulated rivers is a major challenge, particularly in view of the growing demand for renewable energy. While hydropower plays a crucial role in meeting this demand, the impacts on downstream ecosystems are not negligible. In particular, seasonal variations in flows and rapid fluctuations in water levels, known as hydropeaking, may pose complex environmental challenges. This context requires reconciling hydroelectric power generation with the preservation of aquatic ecosystems. To meet these challenges, detailed analysis on a holistic river scale of environmental variables influenced by hydraulic regulation is essential. Hydraulic river modelling is a key tool in this approach, enabling us to examine river dynamics and their impact on habitats. However, conventional models are often restricted to simplified models due to a limited amount of available data. Detailed models are often costly and time-consuming to develop. Simplified models, on the other hand, lack accuracy, particularly at low flow rates. The novel Green LiDAR technology, with its ability to provide fine, detailed bathymetry, offers promising potential for overcoming these limitations by enabling the construction of accurate, large-scale models. The Heddøla River in Norway was selected as a case study focusing on the impact of hydropeaking on the aquatic ecosystem, and in particular on salmonids. These species, sensitive to habitat disturbance, are often used as key indicator species of river ecosystems health. This research aims to develop a model capable of better understanding and anticipating environmental impacts by integrating dat a from detailed bathymetry using green LiDAR. The model will propose holistic approaches for optimising hydroelectric operation and ecological conservation to achieve mutually beneficial outcomes.

DOI: https://doi.org/10.64697/iahr.proc.ise2026.abs.168

Year: 2026