A method for applying fluvial geomorphology in support of catchment-scale river restoration planning

Description/Abstract

1. This paper reports on an extension to the use of Fluvial Audit survey to include a subjective and adaptive multi-criteria assessment (MCA) process that integrates scientific literature and observational data to develop three reach-scale indices of: (a) channel modification; (b) channel function (sediment store or source); and (c) naturalness. These indices are nested within an overall conceptual model of channel evolution and used to underpin catchment scale river restoration.
2. The approach is described and applied to a small groundwater dominated river in the UK. The results show that over 48% of the total main river was in a degraded state relative to a conceptual model of a natural reference state. Only 23% of the river was in a near-natural state.
3. MCA classifications were translated into a set of management actions necessary to return each reach to a near-natural condition. These are described.
4. The method offers a transparent decision support for stakeholders that can incorporate differing scientific evidence. The use of MCA enables flexibility in terms of the relative importance of scores and weights placed upon factors in the final classification. This makes the approach amenable to stakeholder and public consultation.