Rivers require a balanced amount of daylight but are frequently exposed to suboptimal light conditions. Urban streams often suffer from a lack of daylight being hidden under roads, and other streams lack shade, such as in areas of intense agriculture. Restoration efforts tend to neglect light management aspects, even though we know that light environment affects water quality, water temperature, and the communities of plant and animal species living in streams. The RE-FLECT project team is creating tools to visualise alternative restoration scenarios which include the daylight component.
Integrating daylight in river restoration
Daylight shapes river biodiversity, water quality and ecosystem services. However, the exposure of rivers to daylight is often suboptimal: Rivers in areas of intensive agriculture, where trees along rivers have been removed to maximise usable area, often receive too much daylight. In urban environments, on the other hand, rivers are often in pipes or tunnels and lack daylight. ‘River daylighting’ describes a process of opening up of buried urban rivers to daylight. Following such river daylighting, strong positive effects on water quality and biodiversity have been observed.
Negotiating conflicting interests
River restoration is often challenged by conflicting land interests and differing perceptions of restoration goals by the various stakeholders. The team identified visualisations as a useful tool for negotiating solutions on river daylighting across different stakeholder interests. To that aim, the project will provide a tool to visualise various river restoration scenarios. Depicting alternative scenarios facilitates interactive and informed discussions among stakeholders, and raises awareness for the integration and role of daylight in river restoration. After the project, the tool will be made freely available on a public website.
Connecting different perspectives
Under the scientific lead of Prof. Fritz Kleinschroth at the University of Hannover, the project combines ecology, computer science, engineering, social sciences and landscape planning. Stakeholders are involved early in the process. Novel methods such as drone imagery, artificial intelligence and co-learning processes with stakeholders are incorporated. The two case studies are located in Switzerland and Scotland, allowing the comparison of different restoration frameworks.
The project will strengthen evidence-informed decision making and support advocacy for the importance of daylight in river restoration. With its practice-driven, international and interdisciplinary approach and the involvement of a variety of stakeholders the project was unlikely to receive funding by public funders. Although the importance of river restoration is underlined by the UN Decade of Ecosystem Restoration, integrating daylight into this topic is still largely neglected.
