Lucie Clavel

A generic framework for scenario exercises using models applied to water-resource management

Natural-resource management that concerns multiple agents with a variety of interests can be facilitated by integrated assessment methods which include modelling and/or stakeholder participation. Integrated assessment methods are increasingly used for scenario approaches that enable policy-makers to explore possible futures and assess potential consequences of different policy or management strategies. The paper proposes a conceptual and operational framework to illustrate a scenario exercise, based on a previously developed model, by building on recently published progress on the participatory and model-based assessment approach. This framework focuses on information flows in two key operational phases, problem specification and adaptation of model outputs, where scientists and stakeholders interact. In both phases, transformation steps convert narrative information into a quantitative form (and vice-versa), thereby enabling scientists to apply computer models and decision-makers to get confident in model predictions. On the basis of four case studies aimed at solving complex water-resource management problems, we illustrate the difficulties, constraints and questions of each step of the proposed framework and present original solutions. This framework, which can be applied to all natural-resource management issues, clearly defines the step(s) at which each partner should be involved in a scenario exercise and his/her contribution. Consequently, by having greater foresight and transparency, the framework determines the nature of interactions between scientists and non-scientists. A posteriori, it also describes how a scenario exercise was conducted.

A Modelling Solution for Developing and Evaluating Agricultural Land-Use Scenarios in Water Scarcity Contexts

To meet sustainability challenges, regional water management and planning require approaches that assess the land-use visions of various stakeholders using their own evaluation criteria. Models and information systems are keystones in such integrated assessment activities. SPACSS (the SPAtial Cropping System Scenarios builder and evaluator) is a modelling solution that aims to help decision-makers evaluate normative land-use scenarios. A prototype of SPACSS was developed to explore concerns raised by a dam-building project in south-western France, specifically the relation between cropping system distribution and water uptake. This paper presents the initial steps of SPACSS development by scientists and agricultural experts and its evaluation by users through alternative scenarios of maize cropping (altering either its precocity or management to reduce irrigation). SPACSS can represent a wide range of land-use scenarios and aggregate impact indicators at several spatial and temporal scales. Although SPACSS served as a solid support for discussions with stakeholders and decision-makers, it needs modifications to represent more realistic, and thus more complex, land-use scenarios. These modifications will make SPACSS potentially valuable for dealing with a variety of issues concerning agricultural landscapes, far beyond the single question of quantitative water management.