The Water-Energy-Food Nexus of Naxos - The dynamic of Self-Sufficiency through traditional techniques

The Water–Energy–Food Nexus (WEF Nexus) constitutes a contemporary analytical framework that highlights the functional interdependence of three fundamental resources essential for the sustainability of societies. Understanding and managing this interdependence in a holistic manner is particularly critical in regions characterized by strong natural constraints, pronounced seasonality, and intense pressure on natural resources, such as Mediterranean island systems. This diploma thesis examines the Water–Energy–Food Nexus on the island of Naxos, the largest island of the Cyclades, which is characterized by intense agricultural activity, significant tourism development, and limited water availability. Despite its rich natural endowment, Naxos exhibits a high dependence on external inputs of water and energy, rendering it vulnerable to climatic variability, energy crises, and cost increases. The main objective of this study is to investigate the potential for enhancing local self sufficiency through the utilization of traditional and low-technology-intensity practices, with particular emphasis on the collection and use of rainwater. The analysis is based on extensive spatial processing of GIS data and the division of the island into a regular grid of cells, within which available roof surfaces and road networks, hydrological inputs, and local water demand for domestic use and irrigation are estimated. In parallel, demographic characteristics, land uses, primary sector activities, and tourism dynamics are taken into account in order to capture the spatial distribution of demand. The study demonstrates that, despite the decline in precipitation in recent years and the high degree of seasonal variability, Naxos possesses significant unexploited water potential, which can be harnessed through rainwater harvesting systems from roofs and roads, as well as through traditional storage practices such as cisterns. The integration of these solutions into the existing water management system can substantially reduce pressure on groundwater resources and enhance water security. Through the cell-based analysis of the grid, it emerges that targeted, decentralized management of water resources can meet a considerable share of domestic and irrigation demands, particularly in the agricultural sector, while simultaneously reducing energy requirements for pumping and desalination. This approach strengthens the functional coherence of the Water Energy–Food Nexus and highlights the importance of reintroducing circular, locally adapted practices. Moreover, it may serve as a model for similar Mediterranean island systems, contributing to long-term sustainability.