Rapid assessment methodology for support of strategic lowland river planning

Background

Over the past decade peak discharges in various large European rivers have led to renewed international attention for the matching of safety targets and various other functions of rivers. A problem is that it is often unclear which local and non-local effects different measures will have on the river functions. The common (yet time-consuming and expensive) approach is to model the underlying physical, ecological and institutional processes in every detail. However, it is unclear whether this truly helps to improve the decision making process. Although a growing number of scientific tools appears to support water managers, the practical application is still limited for a number of reasons:

• The occurrence of blank spots where no measures were or could be assessed
• A lack of flexibility to cope with changing future conditions or end-user requirements
• Difficulties with integration of qualitative and quantitative model concepts.

The latter issue is of particular importance when social, ecological, and landscape quality aspects are to be taken into account.

Objectives

The objective of this project is to suggest a rapid assessment approach to assess the effects of river strategies, consisting of combinations of different measures, on the river functions. The proposed methodology is based on minimal model and data requirements to achieve maximum flexibility under changing end-user requirements. Fuzzy set theory, a technique widely applied to describe qualitative model concepts, will be used to integrate qualitative and quantitative river expertise.