Vulnerability assessment of groundwater resources: A modelling-based approach to the Mancha Occidental aquifer, Spain

The semiarid Mancha Occidental aquifer represents a paradigmatic case of intensive groundwater use for agriculture. Irrigation has proven a catalyst for welfare in the area over the last three decades, if at a significant environmental cost and while raising concerns as to its mid-term sustainability. This paper describes an interdisciplinary exercise of scenario design and modelling, providing a methodology to couple hard-science numerical modelling approaches with the involvement of key water actors. Given the long-standing conflicts in the area, modelling work largely focuses on carrying out a vulnerability assessment rather than on trying to find solutions. The system's most resilient aspects and its drivers for change are identified, while their potential implications for aquifer sustainability are assessed under the light of the mandatory objectives established by the European Union Water Framework Directive for all Member States. Whereas modelling results imply that such objectives are unlikely to be met, a vulnerability assessment suggests that even adverse scenario pumping patterns could be sustained in the mid- to long-term (two to four decades).