Climate change will likely result in major changes to the hydrologic cycle and terrestrial ecosystems in the coming decades. Furthermore, political decisions and both social and economic framework conditions are changing land utilisation. The hydrological ecosystem services may come under pressure as a result of climate change. These include, for example, the supply of drinking water, flood control, recreation and the use of waterpower. If the ability of the ecosystems to provide these hydrological ecosystem services is now restricted, this will result in rising costs due to flooding, water shortages or impaired water quality. The aim of the HydroServ project was to generate greater understanding of the whole value chain of hydrological ecosystem services and to set out suitable measures for politicians, in order to ensure that hydrological ecosystem services are maintained.
The study is based on the results of a land use decision model, an eco-hydrological model, a choice experiment and other evaluation methods for hydrological ecosystem services. The results were integrated on the basis of a Bayesian network. The corresponding case studies were carried out in the catchment area of the Kleine Emme. The region corresponds roughly to the UNESCO Entlebuch biosphere.
The results show that a forest growth scenario with a forest expansion of 20% triggers the highest willingness to pay among the population. At the same time, however, there is only a minimal reduction in the run-off peak. If the willingness to pay ascertained is implemented as an incentive payment in a liberal agricultural market, the resulting forest growth would, however, be only relatively low. The influence of the change in land use on the run-off volume of the Kleine Emme is either not as high as expected or cannot yet be mapped in the models used. Additionally, it is difficult to steer the offer of hydrological ecosystem services via land management in heavily regulated areas with little change in land use compared to the global situation.
Using the knowledge gained, the project should create a basis for political measures aimed at maintaining the hydrological ecosystem services. Sector-spanning land management can contribute towards the development of a diverse landscape and the provision of various ecosystem services.
HydroServ - Vulnerability of hydrological ecosystem services: Integrative analysis under changes of climate and socio-economy with an emphasis on adaptation