Project Overview
Flood-pulse hydrology drives food security in the Mekong River Basin, but hydropower development, climate change, and changes in land-use threaten the connection between the flood-pulse dynamic and sustainable livelihoods in the region. The ASU-UW Sustainable Mekong Livelihoods Project (SMLP), funded by the National Science Foundation’s Innovations at the Nexus of Food, Energy, and Water Systems (INFEWS) Program, seeks to identify and articulate science-based resource management policies to sustain food-energy-water systems in the Lower Mekong River Basin.
About the Mekong River Basin. The South Asian Summer Monsoon drives the river’s natural flood-pulse and connects it to the floodplain. This connection governs nearly all ecosystem processes in the region, from rice production to fisheries. However, the threat of hydropower development, combined with a changing climate and increased conversion of forested lands to agricultural fields, is placing unprecedented stress on the ecological processes, resource users, and governance in the region.
Hydropower Development. The Mekong is one of the last major tropical rivers to remain undammed for much of its length, but the river’s enormous discharge could also generate over 40 GW of power, which may hold the key to the region’s economic development. Over 20 hydropower dams are already in place for one major tributary alone, with an additional 26 already planned. Dam construction stands to alter the natural flood-pulse dynamic by slowing the delivery of flood-pulse waters downstream. Broad-scale changes to the natural flow regime of the river may have negatively impact fish populations and decrease water supply to rice fields.
Climate Change. Climate change will alter rainfall amounts and may alter the timing of the South Asian Summer Monsoon and ensuing floods. But the joint effects of climate change and hydropower development on flood-pulse timing and the magnitude of impact on sustainable livelihoods in the region is much less certain. Significant changes to the flood-pulse dynamic may affect the reproductive migration patterns of fish and thus catch numbers in the MRB, one of the largest freshwater fisheries in the world. Flood-pulse changes may also shift fish community composition towards species with higher toxins and fewer nutrients. Similarly, though increased or continuous flooding maybe improve overall rice crop yields, that yield will likely be higher in Arsenic and lower in essential nutrients, like Zinc.
Land-Use, Land-Change. The Mekong River Basin has undergone extensive land-use changes since 1950 due to commercial logging and the conversion of forest lands to agriculture. The conversion of riparian forest to agriculture, especially irrigated rice, may have a substantial impact on the region’s water budget and surface hydrology.
Proposed Research. The SMLP will provide a quantitative framework for predicting the effects of hydropower development, climate change, and land-use changes on the Mekong River Basin flood-pulse, freshwater biodiversity, and both yields and nutritional quality of fish and rice, two key aspects of food security and sustainable livelihoods. Researchers will optimize a coupled-modeling platform to reveal mechanisms connecting fish yield and ecosystem processes to the timing, magnitude, and decadal-scale sequence of the flood-pulse. Field sampling efforts will seek to quantify nutrient and contaminant loads in fish and rice, which will inform how threats to the Mekong River Basin impact human health and well-being. Finally, researchers hope to estimate resiliency measures for the Mekong River Basin to adverse climate, political, and economic scenarios by formulating risk mitigation recommendations and prioritize communication with stakeholders to maximize the research efficacy.