Sedimentary Crisis at the Global Scale 2

Jean-Paul Bravard is Emeritus Professor of Geography at Lumière University Lyon 2 in France, as well as an honorary member of the Institut Universitaire de France. He has published numerous studies on the Rhône and other rivers.

• Introduction ixChapter 1 Deltas: Young, Fragile and Threatened Environments 11.1 Long-term construction of deltas: general mechanisms 21.1.1 Processes and basic forms 21.1.2 Dynamics of construction and redistribution in progress 21.1.3 Young and unstable areas 51.2 Some of the Earth’s last great natural deltas: two deltas in the Arctic 81.2.1 The Lena Delta 81.2.2 The Mackenzie Delta 91.3 The Earth’s deltas: what is their current situation in the face of terrestrial and marine constraints? 111.3.1 The rise in sea levels 111.3.2 Sedimentary exhaustion of continents 131.3.3 Extraction of resources and accelerated subsidence of deltas 151.4 Subsiding deltas in Southeast Asia 161.4.1 An example of a young, mainly rural delta, the Huang-He 161.4.2 Urbanized deltas in Southeast Asia 161.5 Conclusion 25Chapter 2 Old Societies and Deltaic Crises 272.1 Some vulnerable deltas in the Holocene during the long and medium terms 272.1.1 The Nile Delta, a condensed version of the history of the African climate 282.1.2 The lower Huang-He and its delta: a Holocene metamorphosis under anthropological control 292.1.3 The Rhône Delta during the Holocene: fluvial branches and the coastline record the history of its climate and society 352.2 The Rhine and the Meuse Deltas: from complete control of fluvial and marine waters to attempts at restoration to a natural state 362.2.1 The fight against fluvial floods 362.2.2 Hydraulic works and environmental objectives in the dyked zone 392.2.3 What kind of compatibility or synergy takes place between fluvial restoration and protection against flooding? 412.2.4 Defense of the Netherlands against the sea 422.3 Contemporary imbalances in the Old World 472.3.1 A delta with a reprieve: the Nile Delta 472.3.2 The Rhône Delta: changes in the basin and the delta 522.3.3 The Ebro Delta: alone against the sea 542.3.4 The delta of the Po plain: historical dispersion of weak points 572.3.5 The Danube Delta: still room for hope 592.4 Conclusion 61Chapter 3 Tropical Deltas in Crisis, Between Open and Closed Formations 633.1 A delta that is both open and alive: the Ganges and Brahmaputra Delta 633.1.1 Rivers and a delta 643.1.2 The Ganges–Brahmaputra–Meghna plain, the most populated and the poorest on Earth 653.2 The Mekong Delta in a suspended status 783.2.1 A technical machine, constantly more complex 783.2.2 Extremely worrying emerging factors 873.2.3 What will be the management choices in the future? Giving preference to the scale of the basin 953.3 The Niger Delta: unlimited exploitation of black gold 973.3.1 The deltaic zone 973.3.2 The effects of the extraction of hydrocarbons on the environment 983.3.3 Serious social and political stakes at play 1013.4 The Indus Delta, dramatically dried out 1033.4.1 The delta and its coast 1033.4.2 The deleterious effects of dams on water and sediment fluxes 1033.4.3 A serious environmental, economic and social crisis 1043.5 The Ayeyarwady, initial symptoms of imbalance? 1063.5.1 Burma, a country on the cusp of development 1063.5.2 The Ayeyarwady, an enormous conveyor belt 1073.5.3 The delta: crisis or stability? 1073.6 Conclusion 109Chapter 4 The Aging Delta of a Country in the New World, the Mississippi 1114.1 New Orleans: an “inevitable city on an impossible site” 1114.1.1 “Discovering” the river 1114.1.2 At the origins of New Orleans 1124.1.3 An area with serious issues at stake 1134.2 Floods and protection of the lower Mississippi valley and the delta since 1717 1164.2.1 Initial protections 1164.2.2 The beginning of generalized protections 1174.2.3 The 1927 flood in the Mississippi valley 1184.2.4 The Jadwin plan (1928) 1194.2.5 Current protection elements 1204.3 The “deltas” in the lower Mississippi valley, from wilderness to the current crisis 1204.4 The Mississippi Delta stricto sensu: a natural zone in crisis 1244.4.1 Flow and landscape dynamics 1244.4.2 The Atchafalaya and its deltaic lobes 1274.4.3 The conversion of delta marshes into free water and coastal regression 1294.5 Hurricanes and their effects on the Mississippi Delta 1324.5.1 Hurricane Katrina 1324.5.2 What does the future hold for New Orleans? 1344.6 Sediments in the Mississippi and equilibrium of the delta 1374.6.1 Simply a reduction in inputs or a sediment deficit? 1374.6.2 The rise in sea levels and climate change 1384.6.3 Reconstruction of the marshes 1384.6.4 Sedimentary management of deltaic branches and the future of the marshes 1394.6.5 Coastal protection plan 1404.7 Conclusion 141Chapter 5 What Strategies Can Help Overcome the Delta Crisis? 1435.1 Delta dynamics: contrasting budgets on a global scale 1435.1.1 The progress of analytical approaches adds complexity to the understanding of deltas on a global scale 1435.1.2 The unforeseen effects of scientific choices 1455.1.3 Open, vulnerable systems 1475.2 Some control logic for rivers and deltas 1485.2.1 Situations involving crises and knowledge 1485.2.2 Contemporary hydraulic engineering pitted against the dynamics of economic domination 1495.2.3 Scientific knowledge at the service of policies on rivers and on their deltas: the case of the Mekong 1515.2.4 Avatars and tribulations of geopolitics 1535.2.5 Expert appraisal and conquest of engineering markets on deltaic land 1545.3 What sustainability is there for deltas in the 21st Century? Comparative approaches 1585.3.1 The typology of deltas as a function of the changes expected in the risk profile 1585.3.2 Typology of deltas as a function of their energy consumption 1595.3.3 The degree of vulnerability or the relative vulnerability of deltas to current changes 1605.3.4 The notion of the tipping point of a delta and of the socioeconomic system 1615.4 Actions at the scale of the continental fluvial system to rebalance the deltaic systems 1625.4.1 Implementation of actions of sedimentary management 1625.4.2 Establishment of current and future sediment budgets 1655.5 The actions developed in the deltaic system in response to crisis situations 1665.5.1 Structural solutions: dykes and fluvial levees 1665.5.2 Some solutions for correction of the sedimentary deficit of deltaic plains 1695.5.3 The sustainable solutions 171Conclusion 177Glossary 179References 185Index of Place Names 205Index of Common Words 211