Quantification of the land-use pattern and areal effects of the hydropower development in Norway

Renewable energy sources are being increasingly utilized in order to mitigate climate change and phase out the use of fossil-based fuels. However, the impact of developing such energy sources on the land and ecosystem needs to be assessed and mitigated properly to avoid any source of problem shifting.

Hydropower is considered nationally and globally the dominant source of renewable energy that can effectively contribute to reducing the usage of fossil fuels as well as being a backbone to help other renewable energy sources with their problem of variability due to its flexibility of production. However, the alteration of the land dynamics due to its deployment varies significantly depending on various spatial and technological factors.

In Norway, more than 70% of hydropower production was developed in the period between 1950 and 1980.  yet, the identification of the land system used for this development and the alteration of the landscape remains unknown.

This work contributes to the limited insights of quantifying the land used for hydropower development in Norway and how the land has transformed due to this development over time. We classified historical aerial images representing the areas for 40 hydropower systems in Norway counting for 8.1 GWh installed capacity which is 24% of Norway’s total hydropower installed capacity and 12% of the total reservoir area. We analyzed what kind of land was used for this development and compared these historical images with recent images to assess the land use change surrounding these hydropower systems with a 1 km buffer zone. 

We found that 63% of the total reservoir areas were already existing water bodies while 9% of the vegetation land was used for this development. We also found that 84% of the reservoirs were built on existing lakes or lakes that were expanded due to hydropower developments.

Additionally, we found that vegetation percentage either remained still or continued growth in most of the analyzed schemes while urban development was slightly small counting only for scattered cabins deployment and construction of roads.  The results of this work help unveil the uncertainties between land dynamics and hydropower development in Norway.