Abstract
<title>Abstract</title> <p> This study presents an integrated methodological framework that links participatory processes with quantitative modelling to support sustainable and adaptive management of the Water–Energy–Food–Ecosystem (WEFE) nexus under increasing resource scarcity and climate change. Conceptual models co-created with stakeholders are translated into a dynamic, empirically validated model capable of reproducing observed system performance. The approach is applied to the Segura River Basin (south-eastern Spain), one of Europe’s most water-stressed regions and highly dependent on the Tagus–Segura inter-basin transfer. The model captures feedback across WEFE components and enables the evaluation of climate change scenarios and stakeholder-defined policy pathways, including potential transfer reductions. Results indicate a progressive deterioration in nexus performance under increasing climatic pressure, particularly under the more extreme SSP5–RCP8.5 scenario. The analysis reveals significant trade-offs between water supply reliability, which is estimated to decline by around 40%, and energy use, which may increase by up to approximately 6.5% as desalination and groundwater abstraction expand. Agricultural production also shows a decreasing trend, with reductions of up to about 17%, reflecting the system’s sensitivity to water availability constraints. Overall, the results show how climatic pressures and water supply limitations reshape cross-sectoral trade-offs over time, affecting water security, agricultural productivity, energy consumption, and environmental sustainability. The study highlights the value of participatory modelling framework as a decision-support tool for supporting informed management of water-scarce WEFE systems <italic>.</italic> </p>