IHE Delft project creates web application to assess nature-based solutions for climate adaptation

The IHE Delft-led part of the EIFFEL project, launched in 2021 and concluded earlier this year, evaluated multiple nature-based solutions (NBSs) for climate adaptation for their effectiveness in improving water retention and soil carbon levels. The findings were integrated into a user-friendly web application, featuring maps and charts to help local stakeholders visualize and implement the proposed strategies.

Project leader Andreja Jonoski, Associate Professor of Hydroinformatics at IHE Delft, said the application could be modified and used for basins other than the Aa or Weerijs.

“The kind of nature-based solutions to be applied depends on the objectives,” Jonoski said. “This project looked at drought, but to determine which solutions are required, one needs to look at different factors like flooding, landscape, recreation. In the end, it is up to the decision-makers in the province to decide what they do. This application helps them base their decisions on scientific findings.”

Project participants set up, calibrated and validated a hydrological model using both earth observation (GEOSS) and local data. This model produced results in terms of various hydrological variables, such as river discharges, groundwater levels, soil moisture and actual evapotranspiration rates.

The application uses key performance indicators such as surface water availability, groundwater availability and the soil moisture index to assess current climate conditions and predict future scenarios based on data from the Royal Netherlands Meteorological Institute (KNMI). By simulating different climate change scenarios, the team could design and compare various adaptation strategies.

The pilot project explored multiple nature-based solutions for climate adaptation and evaluated these for their effectiveness in improving water retention and soil carbon levels.

“This IHE Delft pilot demonstrated the potential of combining GEOSS data with local insights to develop effective climate adaptation measures,” Jonoski said. “By focusing on NBS, the project provided valuable tools and strategies to adapt to the impacts of climate change, particularly in water-stressed regions like the Aa or Weerijs catchment. This addresses current environmental challenges but also paves the way for sustainable water management practices in the face of future climate uncertainties.”

The innovative approaches and findings of the EIFFEL project in utilizing nature-based solutions to address climate change challenges were presented at various meetings, workshops and conferences, including the General Assembly of the European Geosciences Union (EGU) in Vienna in April 2024.

The Aa or Weerijs river catchment is a transboundary basin that spans Belgium and  the Netherlands. Historical interventions like sub-soil drainage and canalization have compromised the area's water retention and biodiversity. The Dutch section of the catchment is predominantly agricultural (65%), with natural areas covering 23% and urbanized zones 12%.

In recent years, the region has experienced increasingly severe summer droughts due to climate change, exacerbating the pressure on water resources. The growing agricultural water use, particularly from a booming tree-nursery sector, further strains the system. This is compounded by high demands for protected natural and recreational areas by local communities.

The EU Horizon 2020 EIFFEL project was launched in 2021 to leverage GEOSS as a primary digital platform for creating climate change mitigation applications. With contributions from 19 teams across eight countries, this project set out to address various climate-related challenges through five pilot projects, including the one led by IHE Delft in the Netherlands.