Linking Narrative Storylines and Quantitative Models to Combat Deserti ication in the Guadalentín Watershed (Spain)

Desertification in Spain is largely a society-driven problem, which can be effectively managed only through a thorough understanding of the principal ecological, sociocultural, and economic driving forces (UNCCD 1994). This calls for a more active role of decision-makers and other stakeholders. We present a promising approach, involving stakeholders in the scenario-development process and linking these narrative storylines with an integrated quantitative model. Within the framework of a larger EC-financed project, dealing with desertification in the Mediterranean region, multi-scale scenarios were developed for Europe, the Northern Mediterranean, and four local areas. In the same project, a policy-support system (PSS) was developed. The main objective of this exercise was to establish a link between the qualitative scenarios and the PSS for the watershed of the Guadalentín river in Spain. From the results of two scenario workshops, three scenarios were selected, all linked to the same Mediterranean scenario. Our selection aimed to maximize both the variety in the narrative storylines and the expected output of the PSS. The scenarios were subsequently formalized, ensuring that the same information was present for all three scenarios; semi-quantified (translated) by linking them to the main entry points of the PSS; and quantified by parameterizing the model. The results indicate the potential of the constructed quantitative scenarios. This chapter illustrates the practical potential and pitfalls of linking qualitative storylines and quantitative models. Future research should, however, also focus on the more fundamental theoretical obstacles that are easily overlooked