Examining the coupling and coordination of water-energy-food nexus at a sub-national scale in India - Insights from the perspective of Sustainable Development Goals

The interconnected and interdependent nature of water, energy, and food (WEF), called the WEF nexus, is essential for achieving long-term sustainability in producing and consuming of these three resources. Coupling and coordination degrees, which describe the intensities of interdependence and cooperation between different system components, are convenient for evaluating and managing the WEF nexus for a region or a nation. Although coupling and coordination of WEF nexus evaluations are essential for sharing knowledge about WEF security challenges, none of the studies has examined how coupling and coordination of WEF nexus based on Sustainable Development Goals (SDGs) affects a country's regions. This study developed a Coupling Coordination Degree Model to examine the WEF nexus at India's sub-national (States/Union Territories) level for 2011 and 2021 and address the SDGs. The comprehensive evaluation index and coupling degree, representing the progress score of WEF security and interaction between the WEF security, respectively, were first determined for the core WEF nexus using 29 indicators based on SDG 2 (zero hunger), SDG 6 (clean water and sanitation) and SDG 7 (cheap and clean energy). Subsequently, the degree of coordination reflecting the level of coordinated development on WEF sectors considering the governance, collaboration, and cooperation among stakeholders from different sectors was obtained. The results show that WEF components are strongly coupled with each other in all the Indian States/Union Territories. The results also show that the comprehensive evaluation index increased in 2021 compared to 2011, reflecting improved WEF security. However, the coordination degree of WEF security varied spatially and temporally, reflecting the variations in the coordination among the water, energy and food sectors in various Indian States/Union Territories. However, the coordination degree improved over the years, and consequently, 39 % of the States/Union Territories advanced from intermediate development in 2011 to good development in 2021. This study also identified the States/Union Territories of India that need improvement in the coordination degree of WEF security and suggested different WEF-related policies and programs for improvement. Results also identified that the development in the food sector (SDG 2) is superior to the water (SDG 6) and energy (SDG 7) sectors in most Indian States/Union Territories. This study may help administrators and policymakers identify the States/Union Territories requiring greater attention for implementing the existing or new policies to attain specific resource security.