Sustainably managing resources in a transboundary freshwater basin is a complex problem, particularly when considering the compounding impacts of climate change, hydropower development, and evolving water governance paradigms. In this study, we used a mixed methods approach to analyze potential impacts of climate change on regional hydrology, the ability of dam operation rules to keep downstream flow within acceptable limits, and the present state of water governance in Laos, Vietnam, and Cambodia. Our results suggest that future river flows in the 3S river system could move closer to natural (i.e., pre-development) conditions during the dry season and experience increased floods during the wet season. This anticipated new flow regime in the 3S region would require a shift in the current dam operations, from maintaining minimum flows to reducing flood hazards. Moreover, our Governance and Stakeholders survey assessment results revealed that existing water governance systems in Laos, Vietnam, and Cambodia are ill-prepared to address such anticipated future water resource management problems. Our results indicate that the solution space for addressing these complex issues in the 3S river basins will be highly constrained unless major deficiencies in transboundary water governance, strategic planning, financial capacity, information sharing, and law enforcement are remedied in the next decade. This work is part of an ongoing research partnership between the National Aeronautical and Space Agency (NASA) and the Conservation International (CI) dedicated to improving natural resources assessment for conservation and sustainable management.

This presentation will show an ongoing freshwater health assessment stemming from a partnership between the National Aeronautical and Space Agency (NASA) and Conservation International (CI) that is dedicated to improving natural resources assessment for conservation and sustainable management. The goal of this work is to develop a calibrated satellite- and hydrologic modeling-based tool to support the assessment of hydrologic environmental health and value natural capital in the Lower Mekong River Basin. Vollmer et al., (2018) have presented the social-ecological framework named the Freshwater Health Index (FHI), which takes account of the interplay between governance, stakeholders, freshwater ecosystems and the ecosystem services they provide. The FHI framework and its accompanying indicators are oriented toward management and stakeholder engagement, and they make a significant contribution by providing a systematic, evidence-based quantitative tool that supports the integration between social and ecological nature of fresh waters at the basin level. Since the FHI is intended to be used iteratively, we leverage multiple data products and hydrological modelling capabilities specifically created to improve decision support in the Lower Mekong basin (Mohammed et al., 2018). Mohammed et al. modelling capabilities enable the integration of satellite-based daily gridded precipitation, air temperature, digital elevation model, soil characteristics, and land cover and land use information to drive watershed model water simulations over the Lower Mekong River Basin. Multiple dam reservoirs scenarios have been envisioned and tested based on stakeholder engagement to enhance the results of the integrative social and ecological nature of fresh waters at the Srepok, Sesan, and Sekong (3S) River Basins of the Lower Mekong. This assessment provides a comprehensive picture of freshwater ecosystem health, the services it provides and the status of its governance at the Lower Mekong.