scholarly journals Strategic basin and delta planning increases the resilience of the Mekong Delta under future uncertainty

2021 ◽  
Vol 118 (36) ◽  
pp. e2026127118 ◽  
Author(s):  
R. J. P. Schmitt ◽  
M. Giuliani ◽  
S. Bizzi ◽  
G. M. Kondolf ◽  
G. C. Daily ◽  
...  

The climate resilience of river deltas is threatened by rising sea levels, accelerated land subsidence, and reduced sediment supply from contributing river basins. Yet, these uncertain and rapidly changing threats are rarely considered in conjunction. Here we provide an integrated assessment, on basin and delta scales, to identify key planning levers for increasing the climate resilience of the Mekong Delta. We find, first, that 23 to 90% of this unusually productive delta might fall below sea level by 2100, with the large uncertainty driven mainly by future management of groundwater pumping and associated land subsidence. Second, maintaining sediment supply from the basin is crucial under all scenarios for maintaining delta land and enhancing the climate resilience of the system. We then use a bottom-up approach to identify basin development scenarios that are compatible with maintaining sediment supply at current levels. This analysis highlights, third, that strategic placement of hydropower dams will be more important for maintaining sediment supply than either projected increases in sediment yields or improved sediment management at individual dams. Our results demonstrate 1) the need for integrated planning across basin and delta scales, 2) the role of river sediment management as a nature-based solution to increase delta resilience, and 3) global benefits from strategic basin management to maintain resilient deltas, especially under uncertain and changing conditions.

Author(s):  
Sharon Friel

This chapter explains the role of human activities in driving climate change, and some of its most significant impacts. It discusses justice issues raised by climate change, including causal responsibility, future development rights, the distribution of climate change harms, and intergenerational inequity. The chapter also provides a status update on current health inequities, noting the now recognized role of political, economic, commercial, and social factors in determining health. This section also discusses environmental epidemiology and the shift to eco-social approaches and eco-epidemiology, noting that while eco-epidemiologists have begun to research the influence of climate change on health, this research has not yet considered in depth the influence of social systems. The chapter concludes with an overview of how climate change exacerbates existing health inequities, focusing on the health implications of significant climate change impacts, including extreme weather events, rising sea levels, heat stress, vector-borne diseases, and food insecurity.


Author(s):  
Stephens Tim

This chapter examines the impact of climate change and ocean acidification on the oceans and their implications for the international law of the sea. In particular, it assesses the implications of rising sea levels for territorial sea baselines, the seawards extent of maritime zones, and maritime boundaries. It also considers the restrictions placed by the UN Nations Convention on the Law of the Sea (LOSC) upon States in pursuing climate mitigation and adaptation policies, such as attempts to ‘engineer’ the global climate by artificially enhancing the capacity of the oceans to draw CO2 from the atmosphere. The chapter analyzes the role of the LOSC, alongside other treaty regimes, in addressing the serious threat of ocean acidification.


1969 ◽  
Vol 17 (2) ◽  
pp. 323 ◽  
Author(s):  
RF Parsons

The present distributions of Eucalyptus diversifolia and E. incrassata are described and disjunctions indicated. It is suggested that a former continuous distribution of both species has been fragmented by rising sea-levels in the Quaternary, and that E. diversifolia was more widespread during a period of lower effective rainfall than the present. It is proposed that Quaternary sea-level changes are of importance in the interpretation of the palaeogeography of plant and animal species with disjunctions in the Nullarbor and Roe Plain area. The nature and role of edaphic barriers to migration in this area are also assessed.


2021 ◽  
Author(s):  
Rafael Schmitt ◽  
Matteo Giuliani ◽  
Simone Bizzi ◽  
Mathias Kondolf ◽  
Gretchen Daily ◽  
...  

<p>Rising sea levels, accelerated land subsidence, and changes in water and sediment supply from upstream basins put the major livelihoods and agriculture in global river deltas at risk. Identifying effective and robust strategies to make deltas more resilient will require to systematically address uncertainty while consider the coupling between global, basin and delta scale processes.</p><p>Here, we demonstrate a bottom-up exploratory approach to forecast land loss in the Mekong Delta by 2100 and to identify most effective management levers to fight that land loss through management on different scales. To our knowledge, this is the first time that such a robust approach is applied to study coupled delta and basin systems, thus considering the full range of drivers behind land loss and delta degradation.</p><p>For this analysis, we couple a network-scale river sediment model and a conceptual model of delta morpho-dynamics. Our land loss estimates cover a large range (20 – 90 %), driven mostly by uncertainty about accelerated subsidence from groundwater pumping. However, sediment supply from the basin plays an important role to maintain delta land, especially for low and moderate scenarios of accelerated subsidence. However, sediment supply from the basin is a function of counteracting and uncertain processes. Population growth and agriculture expansion are expected to increase erosion and sediment yield from the basin, but most of this increased sediment load will be trapped in existing and planned hydropower dams, ultimately reducing sediment delivery to the delta as a function of dam siting and design.</p><p>Using more than 2 million Monte Carlo runs of a river sediment model, we find that placement of hydropower dams is the dominant control on sediment supply, far outweighing increases in sediment yield due to land conversion or reduced sediment trapping in dams because of better sediment management. Thus, the future of the Mekong delta will be determined by renewable energy policies in the basin that strategically avoid excessive sediment trapping in dams as well as by effective water management in the delta.</p><p>Our results demonstrate (1) the need for connecting delta and basin scales for managing river deltas world-wide, (2) the contribution of basin-scale sediment management to maximize the resilience of delta land, and (3) the crucial control that dams and reservoirs exert on sediment continuity between rivers and deltas.  </p>


Author(s):  
J. Q. Zhu ◽  
Y. Yang ◽  
J. Yu ◽  
X. L. Gong

Abstract. Surface faults related to land subsidence have been observed in coastal cities, such as Nantong, Yancheng, and Lian Yungang, in Jiangsu Province (CAJS) since the early 1970s. Nowadays, increases flooding and rising sea levels are attributed to subsidence caused by groundwater pumping. In this work we present a brief description of land subsidence in CAJS, we examine the mechanisms of land subsidence induced mainly by groundwater pumping and its evolution and economic implications as well as the implemented measures by the local government to prevent new damage.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1518
Author(s):  
Guosheng Gao ◽  
Lim Hwee San ◽  
Yidan Zhu

Penang Island is an important economic center in Malaysia and most of its population live in the coastal areas. Although previous studies have shown that it is vulnerable to rising sea levels, the combination of sea-level rise and local land subsidence would be devastating. Therefore, the objective of this study is to apply the local land subsidence model to estimate the inundated areas which relate to sea level rise by 2100. Land subsidence is quantified by the SBAS-InSAR technique on the basis of Sentinel-1 radar images for both ascending and descending tracks. For the first time, the geostatistical analyst method is used to merge the different track results and create the land subsidence models, the results show this method can maximize land deformation fields and minimize deformation errors. According to the land deformation results, all of the coastlines in the east of the island have differing medium levels of subsidence, especially in reclaimed lands and building areas. Lastly, the bathtub model is used to quantify the inundated areas by combing regional sea-level rise projection and local land subsidence models under CoastalDEM in 2100 projections. The results of this study indicate land subsidence that would increase 2.0% and 5.9% of the inundated area based on the different scenarios by 2100 projections.


2019 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Zata Izzati Adlina ◽  
Agung Budi Sardjono ◽  
Suzanna Ratih Sari

Abstract: The occurrence of climate change and environmental problems resulted changes in Bandengan urban Village’s settlements, and especially on its physical elements. Bandengan urban Village as a settlement in coastal area was threatened by the “rob” disaster, which means the phenomenon of flooding result of rising sea levels that regularly occur until now. Moreover, there are also threats from high wave disasters, abrasion, Land Subsidence, and flooding. The existence of these phenomena, bring up responses from the community to adapt and survive in the environment from the threat of its disaster. This study aims to determine the form of adaptation that has been done by the community in settlements affected by the “rob” disaster in Bandengan urban Village. The research uses qualitative methods with descriptive approaches, and uses purposefully select sampling techniques. That is by taking the research zone in an areas that are suspected of having the highest risk, and the areas with the lowest risk level from the threat of “rob” disaster in Bandengan urban Village. The analysis was only focus on the physical form of houses element within the settlement, that’s because to get the specific and comprehensive findings. The results showed that the most dominant form of adaptation was divided into three groups, that were the avoidance adaptation was done by moving to another place that was more secure or evacuate, protect adaptation was done by creating dikes and fill with soil, as well as adaptation to accommodate was done by elevating the floor and lifted up the roof of the houseKeyword: Adaptation, Settlements, “Rob” disasterAbstrak: Terjadinya perubahan iklim dan permasalahan lingkungan mengakibatkan permukiman di kelurahan Bandengan mengalami perubahan secara signifikan, khususnya pada elemen fisik permukiman. Kelurahan Bandengan sebagai permukiman di daerah pesisir terancam oleh bencana rob, yaitu fenomena banjir akibat naiknya permukaan air laut yang rutin terjadi sampai saat ini. Selain itu terdapat pula ancaman dari bencana gelombang tinggi, abrasi, Land Subsidence, dan banjir. Adanya fenomena tersebut memunculkan respon dari masyarakat untuk menyesuaikan diri dan bertahan hidup di lingkunganya dari ancaman bencana. Penelitian ini bertujuan untuk Mengetahui bentuk adaptasi yang dilakukan masyarakat pada permukiman terdampak bencana rob di Kelurahan Bandengan. Penelitian menggunakan metode kualitatif dengan pendekatan deskriptif, serta menggunakan teknik sampling purposefully select. Yaitu dengan mengambil zona penelitian pada daerah yang diduga memiliki resiko tertinggi, dan daerah dengan tingkat resiko paling rendah terhadap ancaman bencana rob di Kelurahan Bandengan. Analisis yang dilakukan hanya berfokus pada bentuk fisik elemen rumah dalam permukiman, dikarenakan untuk mendapat hasil temuan secara spesifik dan komperhensif. Hasil penelitian menunjukkan bahwa bentuk adaptasi yang paling dominan dibagi menjadi 3 kelompok, yaitu adaptasi menghindar dilakukan dengan pindah ke tempat lain yang lebih aman atau mengungsi, adaptasi melindungi dilakukan dengan membuat  tanggul dan mengurug, serta adaptasi mengakomodasi dilakukan dengan meninggikan lantai dan meninggikan atap rumah.Kata Kunci: Adaptasi, Permukiman, Bencana Rob


Author(s):  
A. V. Gavrilov ◽  
E. I. Pizhankova

The activation of modern sedimentation on the shallows of the Laptev Sea, which underwent exclusively erosion in the past, has been revealed. It occurs against the background of rising sea levels. In this activation, the key role of reducing the area of sea ice, cryogenic and hydrodynamic processes, initiated by climate warming, was established. Sedimentation, accompanied by the formation of islands, is confined to positive uplift morphostructures.


2015 ◽  
Vol 5 (2) ◽  
pp. 167-174 ◽  
Author(s):  
A. Smajgl ◽  
T. Q. Toan ◽  
D. K. Nhan ◽  
J. Ward ◽  
N. H. Trung ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document