A document by Zijing Wang. Click on the document to view its contents.

We describe a sampling of over two-dozen sociohydrology case studies that advance our understanding of two-way human-water phenomena. These case studies span broad geographic regions, including over 20 countries, and cover cross-cutting themes such as human behavior, social equity, water security, migration, water resources management, and ecological and environmental phenomena. Collectively, the cases reflect progress within the Panta Rhei decade and suggest new pathways for exciting research in the coming era, in particular by showing how socio-hydrologic modes of study transcend many geographical bounds. We synthesize these insights and describe approaches toward innovative modeling and predictive frameworks that promise to assist in real-world decision-making. We further describe how understanding of diverse and pertinent socio-hydrological phenomena relate to the United Nations’ Sustainable Development Goals (UNSDG) and Environment Programme (UNEP) for addressing climate action in a manner that manifests social well-being and resilient communities.

The common-pool nature of groundwater resources creates incentives to overpump that contribute to their rapid global depletion. In transboundary aquifers, users are separated by a territorial border and might face substantially different economic and hydrogeologic conditions that can alternatively dampen or amplify incentives to overpump. We develop a theoretical model that couples principles of game theory and groundwater flow to capture the combined effect of well locations and user asymmetries on pumping incentives. We find that user asymmetries in either energy cost, groundwater profitability or aquifer response tend to dampen incentives to overpump. However, combinations of two or more asymmetry types can substantially amplify common-pool overdraft, particularly when the same user simultaneously faces comparatively higher costs (or aquifer response) and profitability. We use this theoretical insight to interpret the emergence of the Disi agreement between Saudi Arabia and Jordan in association with the Disi-Amman water pipeline. By using bounded non-dimensional parameters to encode user asymmetries and groundwater connectivity, the theory provides a tractable generalized framework to understand the premature depletion of shared aquifers.

International transboundary aquifers provide important water supplies to over 150 countries. Long-term sustainability of these aquifers requires transboundary cooperation and yet only a select few (1%) transboundary aquifers are formally regulated by a treaty. To better understand the drivers and incentives that allow treaties to emerge, we develop a two-player game to model the social dilemma of transboundary aquifer cooperation. The game incorporates socio-economic and hydrogeological features of the system and highlights the importance of trust to evaluate the benefits and risks of any treaty. We validate the game through a case study of the Genevese aquifer, which is governed by the longest-running and most collaborative transboundary aquifer treaty on record. We then focus on the symmetric game between identical players to explore the role of groundwater connectivity, alternative water supply, water demand, and trust on the emergence of transboundary treaties. The solution space highlights how incentives for cooperation are greatest when the value of water is commensurate with the cost of groundwater abstraction. Cooperation requires high trust in situations characterized by water abundance or scarcity. The model further indicates how two different types of agreements are likely to emerge. Treaties that limit abstraction have greater potential when countries have access to an alternative water source, whereas treaties that restrict pumping near the border have greater potential in water-scarce regions with emerging concerns over groundwater depletion. In addition to helping explain the emergence of existing treaties, this framework offers potential to identify aquifers that may be amenable to cooperation.