scholarly journals Planning dam portfolios for low sediment trapping shows limits for sustainable hydropower in the Mekong

2019 ◽  
Vol 5 (10) ◽  
pp. eaaw2175 ◽  
Author(s):  
R. J. P. Schmitt ◽  
S. Bizzi ◽  
A. Castelletti ◽  
J. J. Opperman ◽  
G. M. Kondolf

The transboundary Mekong Basin has been dubbed the “Battery of Southeast Asia” for its large hydropower potential. Development of hydropower dams in the six riparian countries proceeds without strategic analyses of dam impacts, e.g., reduced sediment delivery to the lower Mekong. This will impact some of the world’s largest freshwater fisheries and endangers the resilience of the delta, which supports 17 million livelihoods, against rising sea levels. To highlight alternatives, we contribute an optimization-based framework for strategic sequencing of dam development. We quantify lost opportunities from past development and identify remaining opportunities for better tradeoffs between sediment and hydropower. We find that limited opportunities remain for less impactful hydropower in the lower basin, where most development is currently planned, while better trade-offs could be reached with dams in the upper Mekong in China. Our results offer a strategic vision for hydropower in the Mekong, introduce a globally applicable framework to optimize dam sequences in space and time, and highlight the importance of strategic planning on multiple scales to minimize hydropower impacts on rivers.

Author(s):  
Benjamin Kingsbury

The storm came on the night of 31 October. It was a full moon, and the tides were at their peak; the great rivers of eastern Bengal were flowing high and fast to the sea. In the early hours the inhabitants of the coast and islands were overtaken by an immense wave from the Bay of Bengal — a wall of water that reached a height of 40 feet in some places. The wave swept away everything in its path, drowning around 215,000 people. At least another 100,000 died in the cholera epidemic and famine that followed. It was the worst calamity of its kind in recorded history. Such events are often described as "natural disasters." This book turns that interpretation on its head, showing that the cyclone of 1876 was not simply a "natural" event, but one shaped by all-too-human patterns of exploitation and inequality — by divisions within Bengali society, and the enormous disparities of political and economic power that characterized British rule on the subcontinent. With Bangladesh facing rising sea levels and stronger, more frequent storms, there is every reason now to revisit this terrible calamity.


2003 ◽  
Vol 47 (7-8) ◽  
pp. 165-168 ◽  
Author(s):  
M. Beuhler

Global warming will have a significant impact on water resources within the 20 to 30-year planning period of many water projects. Arid and semi-arid regions such as Southern California are especially vulnerable to anticipated negative impacts of global warming on water resources. Long-range water facility planning must consider global climate change in the recommended mix of new facilities needed to meet future water requirements. The generally accepted impacts of global warming include increased temperature, rising sea levels, more frequent and severe floods and droughts, and a shift from snowfall to rain. Precipitation changes are more difficult to predict. For Southern California, these impacts will be especially severe on surface water supplies. Additionally, rising sea levels will exacerbate salt-water intrusion into freshwater and impact the quality of surface water supplies. Integrated water resources planning is emerging as a tool to develop water supplies and demand management strategies that are less vulnerable to the impacts of global warming. These tools include water conservation, reclamation, conjunctive use of surface and groundwater and desalination of brackish water and possibly seawater. Additionally, planning for future water needs should include explicit consideration of the potential range of global warming impacts through techniques such as scenario planning.


Author(s):  
Akira Hirano

AbstractImportant aspects for understanding the effects of climate change on tropical cyclones (TCs) are the frequency of TCs and their tracking patterns. Coastal areas are increasingly threatened by rising sea levels and associated storm surges brought on by TCs. Rice production in Myanmar relies strongly on low-lying coastal areas. This study aims to provide insights into the effects of global warming on TCs and the implications for sustainable development in vulnerable coastal areas in Myanmar. Using TC records from the International Best Track Archive for Climate Stewardship dataset during the 30-year period from 1983 to 2012, a hot spot analysis based on Getis-Ord (Gi*) statistics was conducted to identify the spatiotemporal patterns of TC tracks along the coast of Myanmar. The results revealed notable changes in some areas along the central to southern coasts during the study period. These included a considerable increase in TC tracks (p value < 0.01) near the Ayeyarwady Delta coast, otherwise known as “the rice bowl” of the nation. This finding aligns with trends in published studies and reinforced the observed trends with spatial statistics. With the intensification of TCs due to global warming, such a significant increase in TC experiences near the major rice-producing coastal region raises concerns about future agricultural sustainability.


Nature ◽  
2015 ◽  
Vol 528 (7582) ◽  
pp. 310-310
Keyword(s):  

Author(s):  
Paul Tschirky

Our environment has been experiencing changes in climate patterns in ways that were not anticipated by past designs. Coastal engineers are increasing at the center of complex multidisciplinary projects. With changing climate, rising sea levels, and growing coastal population centers, coastal engineers are key players in developing solutions for both built infrastructure and natural systems. This presentation will discuss the challenges to coastal engineering and examine some coastal resiliency approaches on recent projects and experiences in the United States.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/prjG4LTU-iU


2021 ◽  
Author(s):  
◽  
Joseph Wellwood

<p>New Zealand’s coastline is rapidly receding. The increased threat of rising sea levels continues to erode the shore line causing extensive and irreparable damage to thousands of coastal properties, often dismantling communities and the kiwi dream of living near the ocean. With global temperatures continuing to rise, all of our coastal communities are at risk. The current measure of response to this issue is through managed retreat, the removal and relocation of all ‘at risk’ buildings in coastal hazard zones. While this approach is successful in preserving the physical structures, it remains an undesirable solution that forces homeowners to abandon their community and the coastline for the safety of higher ground. The retreat is hampered among debate within the effected regions as the forced detachment of long standing communities often results in the loss of ‘sense of place’ that living within a coastal community enables.  This thesis proposes that Haumoana in Hawkes Bay offers the fitting location to introduce an alternative coastal community model that actively responds to the impending hazards whilst retaining the societal poetics. Situated just south of the nearby communities of Te Awanga and Haumoana, two of the most at-risk coastal regions in New Zealand that are currently facing the prospect of dismantlement. The site was specifically chosen due to the fact that erosion is predicted to diminish half its usable land over the next century, this thesis will investigate the potential risks to the respective coastline, the role that this would play in an adaptive community, and the possible design options that can respond and enhance a future sustainable landscape.  This thesis argues that a coastal community can be designed to actively adapt and respond to the threat of erosion rather than being dismantled through retreat; that by adopting design principles that protect the land on which they are placed, the coastal hazards of the region can be lessened; and that an adaptive community model can be achieved whilst retaining the ‘sense of place’ that coastal community’s exhibit.  The thesis proposes that this can be achieved by incorporating and reinforcing natural features of the coast into the architectural design at various scales; accommodating for, and adapting to the imminent threat of erosion; and by invoking principles of sustainable design in company with adaptive planning and resilient design, thereby pushing the standards of coastal planning beyond typical practice.</p>


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