Résumé
This report deals with the values that people hold for ecosystem services provided by fresh water ecosystems (rivers, streams, aquifers), in a catchment of Southern France, characterized by an imbalance between water demand and available resources, and consequent strong tensions between water uses. An ecosystem services based approach is proposed to holistically assess current and potential benefits of aquatic ecosystems at catchment level and identify trade-offs and synergies between them. After a presentation of the conceptual framework related to ecosystem services of fresh water ecosystems (section 2), section 3 of the report explores the literature in economics and social and human sciences on the notion of value. It focuses in particular on the criticisms towards the utilitarian conception of values used in neo-classical economics and on the standard techniques used to assess them. An integrated framework is then proposed to address the multiple dimensions of values of ecosystem services. In section 4 are presented the diverse methods to assess this plurality of values: (i) standard methods of economic valuation based on stated preferences, but also (ii) psychometric tests to reveal individuals' transcendental values, (iii) non-monetary valuation techniques applied to ecosystem services and (iv) deliberative valuation methods, to account for shared and social values, articulated by groups of people in the frame of social processes. Section 5 of the report presents our research hypotheses and outlines the non-monetary deliberative valuation approach implemented in the case study, the upstream part of the Gardons river basin (the Cévennes), confronted with quantitative and qualitative water management problems. The implementation of the proposed approach in the case study is described in volume 2 of the report.