Groundwater Connections and Sustainability in Social-Ecological Systems.

Groundwater resources are connected with social, economic, ecological, and Earth systems. We introduce the framing of groundwater-connected systems to better represent the nature and complexity of these connections in data collection, scientific investigations, governance and management approaches, and groundwater education. Groundwater-connected systems are social, economic, ecological, and Earth systems that interact with groundwater, such as irrigated agriculture, groundwater-dependent ecosystems, and cultural relationships to groundwater expressions such as springs and rivers. Groundwater-connected systems form social-ecological systems with complex behaviors such as feedbacks, nonlinear processes, multiple stable system states, and path dependency. These complex behaviors are only visible through this integrated system framing and are not endogenous properties of physical groundwater systems. The framing is syncretic as it aims to provide a common conceptual foundation for the growing disciplines of socio-hydrogeology, eco-hydrogeology, groundwater governance, and hydro-social groundwater analysis. The framing also facilitates greater alignment between the groundwater sustainability discourse and emerging sustainability concepts and principles. Aligning with these concepts and principles presents groundwater sustainability as more than a physical state to be reached; and argues that place-based and multifaceted goals, values, justice, knowledge systems, governance, and management must continually be integrated to maintain groundwater's social, ecological, and Earth system functions. The groundwater-connected systems framing can underpin a broad, methodologically pluralistic, and community-driven new wave of data collection and analysis, research, governance, management, and education. These developments, together, can invigorate efforts to foster sustainable groundwater futures in the complex systems groundwater is embedded within.

Social tipping points in global groundwater management.

Groundwater is critical to global food security, environmental flows, and millions of rural livelihoods in the face of climate change 1 . Although a third of Earth's largest groundwater basins are being depleted by irrigated agriculture 2 , little is known about the conditions that lead resource users to comply with conservation policies. Here we developed an agent-based model 3,4 of irrigated agriculture rooted in principles of cooperation 5,6 and collective action 7 and grounded on the World Values Survey Wave 6 (n = 90,350). Simulations of three major aquifer systems facing unsustainable demands reveal tipping points where social norms towards groundwater conservation shift abruptly with small changes in cultural values and monitoring and enforcement provisions. These tipping points are amplified by group size and best invoked by engaging a minority of rule followers. Overall, we present a powerful tool for evaluating the contingency of regulatory compliance upon cultural, socioeconomic, institutional and physical conditions, and its susceptibility to change beyond thresholds. Managing these thresholds may help to avoid unsustainable groundwater development, reduce enforcement costs, better account for cultural diversity in transboundary aquifer management and increase community resilience to changes in regional climate. Although we focus on groundwater, our methods and findings apply broadly to other resource management issues.