Title: A multicriteria spatial analysis of erosion risk into small watersheds in the low Normandy bocage (France) by ELECTRE III method coupled with a GIS

Authors: Francis Macary, Dominique Ombredane, Daniel Uny

Addresses: Amenities and Dynamics of Rural Areas Research Unit, Cemagref, Bordeaux Center, 50, Avenue de Verdun-Gazinet-F-33612 Cestas Cedex, France. ' INRA – Agrocampus Ouest, Ecology and Ecosystems Health Research Unit, 65 Rue de Saint Brieuc, F-35042 Rennes Cedex, France. ' Amenities and Dynamics of Rural Areas Research Unit, Cemagref, Bordeaux Center, 50, Avenue de Verdun-Gazinet-F-33612 Cestas Cedex, France

Abstract: In environmental risk analysis, many explanatory factors, often with highly complex interaction relationships, need to be taken into account. This is the case, for example, in the relation between agricultural practices and the quality of superficial aquatic ecosystems. Suspended solids are responsible for clogging salmonid spawning areas and hence for reductions in their populations. We studied the risks of erosion across two small watersheds in Normandy (France) on the scale of the agricultural plot – the level on which good practices can be applied. Plots were defined according to quantitative as well as qualitative criteria: connectivity to the stream, slope, plant cover, presence of embankments and erosion of the banks in the case of plots beside the river. By combining the ELECTRE III multicriteria analysis method to a geographical information system (GIS), it was possible to discriminate zones that present a risk with respect to particle emission and then to present the results in map form to provide decision-making aid for local actors.

Keywords: ELECTRE; multicriteria decision making; MCDM; decision analysis; geographic information systems; GIS; watersheds; environmental risks; risk assessment; erosion; total suspended solids; TSS; bocage; sequential cropping; France; spatial analysis; erosion risk; soil erosion; water pollution; water quality; salmonid spawning areas.

DOI: 10.1504/IJMCDM.2010.033685

International Journal of Multicriteria Decision Making, 2010 Vol.1 No.1, pp.25 - 48

Published online: 17 Jun 2010 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article