Perceptual Modelling Of Environmental Indicators To Assess Land Uses Impacts On Water Quality

The stream functioning is closely influenced by land uses, along the stream itself and throughout the catchment. Land uses can be seen as both the expression of the natural environment and the result of increasing human activities. Land uses generate various (in kind and intensity) pressures (positive or negative) that alter river water quality at different scales of time and space. The objective of this research is to conceptualize and quantify the interactions between river water quality and land use through spatial modelling. Our methodology is based on (i) the design of a system of indicators using the DPSIR framework and (ii) the development of the relevant environmental indicators able to characterize the spatio-temporal evolution of water quality, land uses and their interactions. The methodology is applied on the Saône River (France). Water quality status is characterized by a bioindicator based on invertebrate population. Pressures indicators were identified during a literature review, and built according to the nature of the land use, their distance to rivers and their location in the watershed. The construction of indicators was limited by the representativeness and homogeneity of data gathered from national databases. These data were supplemented by the results of a very high spatial resolution land use mapping work and a spatio-temporal change detection analysis.