Assessing vineyard sustainability through a Water-Energy-Food-Ecosystems Nexus indicator using System Dynamics Modelling

Optimizing agricultural inputs at the farm scale requires a holistic understanding of water, energy, food, and ecosystem (WEFE) interdependencies. This study develops a composite Water–Energy–Food–Ecosystem Nexus Indicator (WEFENI) and applies System Dynamics Modelling (SDM) to assess vineyard sustainability in northern Spain. This study is the first to introduce WEFENI at a fine spatial resolution, applying it at the grape variety and small-plot level to capture sustainability differences within a single farm. Five key indicators water footprint, carbon footprint, energy footprint, income, and productivity were selected based on their relevance to environmental and socio-economic performance. Primary data were collected through structured questionnaires and field measurements, complemented by secondary data from meteorological and governmental databases. The indicators were normalised, weighted using the CRiteria Importance Through Intercriteria Correlation (CRITIC) method, and aggregated into a composite WEFENI. The dynamic model was constructed to simulate monthly interactions within the WEFE nexus, enabling scenario-based analysis and capturing feedback-driven behaviour across resource systems. Results show substantial variation in WEFENI scores across agro-climatic zones and grape varieties. The Low Zone achieved the highest score (0.739) due to gravity-fed irrigation and low energy demand, while the High Zone scored lowest (0.556) because of energy-intensive pumping. At the variety level, 15 grape varieties demonstrated a balance between high sustainability and profitability demonstrating the added value of WEFENI in identifying optimal crop choices. Scenario analysis revealed that precision agriculture produced the greatest improvement in WEFENI (+0.102), followed by improved energy efficiency (+0.056), whereas reduced precipitation decreased the score (–0.056). The proposed framework enhances the replicability of farm-level sustainability assessments by explicitly defining indicator selection, system boundaries, and calculation procedures. The integration of WEFENI with SDM enables dynamic, scenario-based evaluation of trade-offs and synergies, providing a robust decision-support tool for sustainable resource management in agriculture.