A manual and web based tool to support the valuation of ecosystem services in Flanders, Belgium

Sara Ochelen, Department of Environment, Nature and Energy of the Flemish government (LNE)

Ex ante evaluation of new infrastructure projects often relies on cost benefit analysis. Such infrastruc­ture, like a new road or a new dock in a seaport, can have a significant impact on ecosystems and the services they deliver. To facili­tate the integration of this impact in the project evaluation, we want to quantify and to express it in monetary terms, the same unit as the other elements of a cost benefit analysis. With this purpose, the Flemish government commis­sioned a study to quantify and value the ecosystem services of (semi)-natural land use, including forests, grasslands and freshwater eco­systems.

The findings of this study are summarised in a manual and an easy to use web tool called ‘natuur­waardeverkenner’ (nature value explorer). The study looked both into cultural services and regulating services. Cultural services are the amenity and non-use value. Regulating services include denitrifica­tion, N, P and C sequestration in soils and forest biomass, improvement of air quality, noise mitiga­tion.

The quantification of regulating services is based on easy to use methods that could be integrated in the web instru­ment and less on extensive process based models that require expert to operate. Regulating services are mostly valued through avoided (damage) costs e.g. health costs related to air pollution and avoided investment costs to assess the value of nutrient removal. The value of cultural services is based on a large choice experiment. A value function for natural landscapes was estimated and we found that the willingness to pay depends on the characteris­tics of the natural landscape and characteristics of the respondents.

As the tool/manual needed to serve for a multitude of cases, straightforward unit benefit transfer methods per hectare were considered insufficient. Instead, value function approaches were devel­oped. Specific characteristics of a nature area and its surroundings are taken into account in order to calculate its value.