Author: riverlab

Can the Mekong Delta be saved from drowning?
The drowning Mekong delta. The continued existence of the Mekong Delta is threatened by anthropic drivers. Continued business-as-usual resource management in the basin will result in the delta surface dropping by 2 m relative to sea level, which will drown most human and natural values in the delta. Measures to avoid this fate are known, but need to be implemented urgently across scales, sectors, and borders.

May 6, 2022 – The Mekong Delta in Viet Nam could be nearly fully submerged by the end of the century if urgent actions are not taken across the river basin. Continuing with business as usual could drown 90% of this agro-economic powerhouse that’s home to nearly 20 million people – with immense local and global impacts.

Only concerted action by the six countries in the Mekong basin and better management of water and sediments within the delta could avoid such a devastating outcome, argues an interdisciplinary research team in a commentary published today in the journal Science.

Most of 40,000 km2 delta is less than 2m above sea level and is thus prone to climate change induced sea level rise. On top of that, actions in the delta such as over pumping of groundwater and unsustainable sand mining to construct expanding cities across Asia as well as rapid hydropower development upstream threaten the future of the most productive rice basket in Southeast Asia.

“It’s hard to fathom that a landform the size of the Netherlands and with a comparable population might disappear by the end of the century,” said lead author Professor Matt Kondolf from University of California, Berkeley. “Yet, like any river delta, the Mekong Delta can only exist if it receives a sufficient sediment supply from its upstream basin and water flows to spread that sediment across the delta surface, so that land is built at a rate that is equal or greater than global sea level rise.”

In the Mekong, water and sediment flows are increasingly endangered.

“Hungry for renewable energy, countries in the basin develop hydropower dams, which trap sediment, with little regard for system scale impacts. What little sediment reaches the lower Mekong could be mined to meet the demands of the burgeoning real estate sector in the region, which requires great amounts of sand for construction and land reclamation,” summarised co-lead author Dr Rafael Schmitt from University of Stanford.

Shipping in Song Hau, Long Xuyen, Mekong River Delta. Photo by GM Kondolf November 2019. 

But not all the blame can be put to upstream actions and global climate change induced sea level rise. In the delta itself, high dikes have been built to control floods and thus enable high intensity agriculture. This also prevents the fertile sediment from being deposited on the rice fields.

However, the drowning of the delta is not a fait accompli. There are steps that can be taken to allow dynamic, natural processes to help prevent the delta from further sinking and shrinking.

“The consensus amongst scientists on the scale and gravity of the threat to the Mekong delta is crystal clear, but it can be countered by ensuring the river’s waters remain muddy and murky with sediment,” said co-author Marc Goichot, WWF Asia/Pacific Freshwater Lead.

“Countries must choose a better development path for the Mekong river and region – one that is based on ambitious but feasible policies, which support a system-wide approach to energy, construction and agriculture that will build the resilience of the delta and benefit all the people and nature that depend on it. Business as usual would spell disaster for the delta,” added Goichot.

The team identify six measures that are feasible and have global precedents and would significantly increase the lifetime of the delta:

  • Avoid high impact hydropower dams by replacing planned projects with wind and solar farms when possible and if not, building new dams in a strategic way that reduces their downstream impacts;
  • Design and/or retrofit hydropower dams to enable better sediment passage;
  • Phase out riverbed sand mining and strictly regulate all sediment mining, while reducing the need for Mekong sand through sustainable building materials and recycling;
  • Re-evaluate intensive agriculture in the Mekong Delta for its sustainability;
  • Maintain connectivity of delta floodplain by adapting water infrastructure; and
  • Investing in natural solutions for coastal protections on a large scale along the delta’s coasts.

”Although the effectiveness of these measures, particularly if implemented in unison, is little disputed in the scientific community, major roadblocks exist for their implementation,” said Dr Schmitt.

Late afternoon on Ken Rach Gia channel, Long Xuyen, Mekong River Delta. Photo by GM Kondolf November 2019.

Some of those measures would conflict with vested interests of certain actors, such as the sand mining industry and hydropower development, and some measures would require coordination among countries to account for system scale impacts and benefits of individual actions.

Countries would also need to agree that the sustenance of the Mekong delta is an important regional policy objective. In Viet Nam, where most of the delta is located, some recent policies try to counter some symptoms of a sinking delta, but there is little acknowledgement of the existential risk to the delta, nor ambition to work on truly systemic solutions.

Implementing the measures will require participation from national governments and international actors as well as new actors, including from the private sector and civil society. But together it is possible to save the delta from drowning.

“A Mekong delta that will thrive beyond the end of this century is possible – but it will require fast and concerted action in a basin that has been riddled by competition, rather than cooperation, between its riparian countries,” concluded Professor Kondolf.

The article, Save the Mekong Delta from Drowning, was published in Science 6 May 2022 and is available online at https://www.science.org/stoken/author-tokens/ST-468/full

Floods and Equity: A panel discussion

Tuesday 12 May, 1030-1130

Social Science Matrix, UC Berkeley campus (8th floor of Social Science Building)

Greenville, Mississippi, during the 1927 flood.  The flood exacerbated unfair treatment of African-Americans in the area, with Black men forced to work on levee crews.  (photo from Clay 1976, US Army Corps of Engineers) 

Floods are the most destructive natural hazard, both at the national and international scale, and they disproportionately affect people of color and the poor.  To understand this uneven exposure to floods requires that we understand the history of land use and institutional structures that have resulted in current exposure and inequitable allocation of resources for flood protection and for post-disaster aid (‘procedural vulnerability’).  One of the most critical agencies is the US Army Corps of Engineers, whose cost-benefit analysis approach tends to preclude flood risk management projects in poor communities.  Panelists Danielle Zoe Rivera (UC Berkeley) and Jessica Ludy (US Army Corps) will draw upon their research on these topics and discuss pathways to improving on the current situation. 

Please RSVP at https://forms.gle/RdFezN1PocEnzTFJ8 to reserve your spot.

Presented by Global Metropolitan Studies, the Social Science Matrix, and Riverlab, UC Berkeley.

Panelists:

Danielle Zoe Rivera is an assistant professor in the Department of Landscape Architecture and Environmental Planning in the College of Environmental Design. Rivera’s research examines movements for environmental and climate justice. Her current work uses community-based research methods to address the impacts of climate-induced disasters affecting low-income communities throughout South Texas and Puerto Rico. Rivera teaches on environmental planning and design, community engagement, and environmental justice. Her work has been published by the Journal of the American Planning Association, Environment and Planning, the Lincoln Institute of Land Policy, and the International Journal of Urban and Regional Research. She holds a PhD in Urban Planning from the University of Michigan, a Master of Architecture from the University of Pennsylvania, and a Bachelor of Architecture from the Pennsylvania State University. Prior to joining the University of California Berkeley, Rivera taught Environmental Design at the University of Colorado Boulder.

Jessica Ludy (she/her) is the Flood Risk Program Manager and Environmental Justice Coordinator for the San Francisco District US Army Corps of Engineers. Through the Army Corps’ “Technical Assistance Programs,” Jessica and her team partner with communities in the San Francisco District Area of Responsibility to identify and implement solutions for equitable, just, and sustainable climate adaptation. Jessica also leads the San Francisco district’s efforts to implement the federal government’s priorities to advance social and environmental justice. Jessica’s work is informed and inspired by collaborations and scholarship of researchers and colleagues both inside and out of the federal government, and by the decades of environmental and disability justice leadership from indigenous peoples, people of color, and other historically-marginalized groups. Jessica is a co-chair of the Social Justice and Floodplain Management Task Force at the Association of State Floodplain Managers. Prior to the Army Corps, she worked on flood risk management and floodplain restoration as an environmental consultant, a Fulbright scholar, and at nonprofits. Jessica completed her Master’s in Environmental Planning at UC Berkeley in 2009 where her thesis on flood risk perception behind levees sent her down a rabbit hole to change the way we ‘do’ flood risk management… forever. 

Applications open now: ReConnecting Big Rivers collaboration with Jackson State University

Five students and 2 faculty members from JSU will visit Berkeley and conduct field visits to leveed landscapes along the Sacramento River and Delta (19-22 May 2022), and a similar group from Berkeley will visit JSU (Fall 2022) and conduct field visits along the Mississippi River. At the end of each visit, student teams will present their ideas from the weekend’s field visits and brainstorming.

Applications are due 10am Friday 22 April 2022. Learn more →

California State University, Monterey Bay: Assistant Professor of Environmental Science

The Department of Applied Environmental Science at California State University, Monterey Bay (CSUMB) invites applications for a tenure-track faculty position in Environmental Science at the assistant professor rank to begin in Fall 2022. We are seeking candidates with a demonstrated commitment to teaching and research in Earth surface processes, such as fluvial geomorphology, stream hydrology, and/or wildfire-mediated hillslope dynamics. We seek a colleague who will provide leadership in the watershed systems concentration of our Environmental Science, Technology, and Policy B.S. and our Environmental Science M.S. degree programs by engaging in externally-funded, regional research projects that both enrich the student experience and feed a sustained record of publication. The ideal candidate would capitalize on the outstanding research opportunities near CSUMB by responding to the research needs of our community and building upon existing regional partnerships with resource agencies, non- profits, and consulting firms. They would also apply their research to socially relevant environmental watershed issues such as endangered/threatened species and/or water quality and water supply.
Position details and application instructions can be found at: https://apptrkr.com/2718749
Application review will begin February 11, 2022, and continue until the position is filled.

America’s dams are filling with sediment!

US dams are filling with sediment much faster than most people realize. The result is that reservoir storage capacity is being depleted, threatening long-term sustainability of irrigated agriculture and municipal water supplies. There are techniques that can be used to extend the life of reservoirs, but these are rarely implemented. In a paper just published in Journal of Hydrology, Tim Randle and colleagues explain that we need a new paradigm to guide our management of these important components of our national infrastructure. You can access the paper here.

    Restoring Dynamic Fluvial Processes in Urban Rivers: Learning from the Aire and Isar Rivers

    In process-based restoration, the objective is not to create a complex river form directly; instead, interventions are intended to “prompt” the natural processes to restore such forms. The improvements in ecological conditions are actually made over time by flowing water during floods (using the stream’s energy), and by the growth of riparian vegetation (using incoming solar energy). On the Aire River in Geneva, ecological function was restored to a formerly canalized river by providing the river with an espace de liberté. A grid of channels cut into the valley bottom allowed the river to freely flood, erode its bed and banks, and deposit bars, creating complex surfaces on which riparian vegetation established to support the food web of the riverine ecosystem. The diamond-shaped bits of land left between these channels (“lozenges”) gradually erode and evolve as the river migrates, creating complex channel forms. The Isar River in Munich restoration involved adding coarse sediment load, creating erodible bed and banks in place of formerly rigid boundaries, expanding process space for river migration, erosion, and deposition, and increased human access to the river over 8 km. Since restoration, natural transport of sediment has resulted in deposition of gravel bars, whose forms evolve during floods, supporting diverse habitats. The Isar and Aire Rivers provide compelling examples of process-based restoration meeting 4 criteria for process-based restoration: space, energy, materials, and time. They demonstrate the possibilities of urban river restoration to achieve both ecological and social goals through restoration of fluvial process. The paper is available under open access here.

    Network for Engineering with Nature Post-Doctoral Position

    The Network for Engineering with Nature (NEWN) is a multi-institutional research entity for studying the role of natural, built, and social systems as part of an infrastructure portfolio. The network has a major research focus area on the interplay between infrastructure and biodiversity objectives. We are hiring a postdoctoral scholar to generally examine how engineering and design practices can more seamlessly incorporate biodiversity as both a design outcome and a benefit to engineering performance. Specifically, this position will focus on long-term asset management of dams and other freshwater infrastructure (e.g., decisions about removal, repair, divestment, etc.).  Additionally, the position will collaborate closely with other NEWN investigators on a variety of other cutting-edge topics related to natural infrastructure and nature-based solutions. Click here for more info.

    Please also note that N-EWN has other postdoctoral positions currently available on other topics as well. Please refer to here for more info.

    Public Policy Institute of California Position Opening: Research Project Assistant

    Public Policy Institute of California (PPIC) is a highly influential NGO providing expertise to California officials on various policy issues, including a strong emphasis on water. PPIC is hiring one or more temporary, full- or part-time research project assistants. This could be a 6-month full-time position, or for current students a 10-20 hrs/wk position. Dataset management and quantitative analysis in R, STATA, or similar programs, and/or expertise in GIS. Guaranteed consideration for applications received before December 15. The posting for the position can be found here. The position is written assuming the San Francisco office as a base, but remote work would be possible for the right candidate.