High-resolution mapping of land use changes in Norwegian hydropower systems

Abstract

This study provides a high-resolution mapping of land use changes associated with Norwegian hydropower systems. Using high-resolution Norwegian aerial imagery and geodatabases, we assessed land use intensity and changes across 288 power plants. Results show that hydropower infrastructure occupies a smaller land footprint than previously estimated, but cumulative effects of multiple developments require careful management. The study highlights the importance of production density (GWh/km²) as a metric for comparing land use efficiency across different energy sources.

1. Introduction

Hydropower is the dominant renewable energy source in Norway, providing approximately 90% of the country's electricity production. However, hydropower infrastructure—including dams, reservoirs, power plants, and transmission lines—occupies substantial land areas. Understanding the land footprint of hydropower is critical for land-use planning, environmental assessment, and policy development.

Despite its importance, there is a lack of high-resolution land use maps for hydropower in Norway. This study aims to fill this gap by providing detailed mapping of land use changes across 288 hydropower plants, covering various plant types including storage plants, run-of-river plants, and small-scale plants.

2. Data and Methods

This study used high-resolution Norwegian aerial imagery (Norge i Bilder) and GIS geodatabases to map land use around 288 hydropower plants. Land use changes were analyzed over multiple time periods using historical and recent imagery. Production density (GWh/km²) was calculated for each plant as a measure of land use efficiency.

The study sample included plants of various sizes: large storage plants, run-of-river plants, and micro, mini, and small hydropower plants. Data were collected from Norwegian national databases and the Norwegian Water Resources and Energy Directorate (NVE).

3. Results

Results show that large storage hydropower and large run-of-river plants exhibit the highest production densities, at 1264 and 350–396 GWh/km², respectively. Onshore wind shows the lowest production density, 55 GWh/km², indicating lower land utilization. Solar power shows a modest production density of 80 GWh/km².

The land use maps reveal that only a small percentage of the land area allocated to hydropower projects is actually used for infrastructure (dams, plants, reservoirs), while the majority remains as natural or agricultural areas. However, the cumulative impact of multiple plants on the same river system can be significant.

4. Discussion

The findings support the use of production density as a standardized metric for comparing land use efficiency across different energy sources. While hydropower shows high land use efficiency, local environmental impacts (such as habitat fragmentation and flow regime changes) require careful consideration in planning new developments.

Projections show 278–512 km² of additional land needed by 2050 due to onshore wind and solar power development, emphasizing the need for comprehensive planning to mitigate land competition and associated impacts.

5. Conclusion

This research provides the first high-resolution land use mapping of Norwegian hydropower systems at scale. The findings are valuable for decision-makers, natural resource managers, and energy planners. The research advocates for a balanced renewable energy approach that integrates environmental considerations with climate change mitigation.

References

Full references available in the original at ScienceDirect: 10.1016/j.rser.2023.113798