Aryana Libris

Author : Bravard Jean-Paul
Title : Sedimentary Crisis at the global scale 2 Deltas, a major environmental crisis
Year : 2019

Link download : Bravard_Jean-Paul_-_Sedimentary_Crisis_at_the_global_scale_2.zip

Introduction. Deltas are a major component of the Earth’s “coastal fringe”. They are sites where particulate and dissolved materials are deposited, and places where essential biochemical processes take place; their fragile and remarkable equilibrium arises from the complex set of constructive and destructive forces that have been at play at the interface between land and sea for a short period of time in geological terms, six millennia at the most. This gives rise to specific forms and varied typologies, depending on the relative importance of the influencing factors. Over the same period of time, watersheds and the rivers that they feed have been profoundly disrupted by deforestation, agriculture, extraction activities and fluvial engineering, often to the point of no longer being able to guarantee a sufficient contribution to balanced delta functionality, and according to the indications of all evidence, this trend will probably get worse. Finally, climate change is responsible for the rise in sea levels which increasingly attack delta environments that are then incapable of adjusting to the intensity of the process. The second volume of “Sedimentary Crisis at the Global Scale” aims to examine the theme of exits to fluvial systems, in other words through deltas. As receptacles for sediments carried down from the continents, the Earth’s deltas are very young zones when placed in the context of the scale of the Earth’s geological history. However, they have a complex history in the era of continental sedimentary crisis, the reality of which we discussed in the first volume; deltas are at the mercy of the rhythm of rivers. ...