River deltas served as environmental incubators for some of the oldest cities and state-level societies on Earth, provide tremendous ecosystem services and resources, and currently host about 350 million people globally. At the same time, deltas in the Anthropocene have become iconic of the degradation and vulnerability of the world’s coasts, notably through depletion of fluvial sediment supply, direct delta resource exploitation by growing delta populations, and exacerbated subsidence. Massive datasets and conceptual and numerical modelling are permeating delta studies globally, helping us probe better how geoscience can contribute to face the challenges of future delta sustainability, notably in the context of global sea-level rise, through new principles of delta management. Without climate stabilization, the future of deltas could be wholesale drowning.
The course will briefly examine deltas in their initiation, expansion, and progradation/aggradation phases and how these phases have played out with deltas acting as incubators of human development in the Holocene and Anthropocene. The Anthropocene tip-over into global delta vulnerability will be analyzed: in the light of massive delta population growth debouching on delta megacities, fluvial sediment depletion (hydropower dams, reservoirs, and aggregate mining), aggravated subsidence and resource exploitation. Geoscience solutions to mitigate delta vulnerability are rapidly emerging. They notably involve better management of river basin-delta water and sediment connectivity and delta sedimentation-enhancing strategies. The course will be wrapped up with a critical analysis of the chances of delta sustainability, or even mere survival, in the face of various IPCC sea-level rise scenarios. The eventuality of delta drowning as a result of sea-level rise needs to be envisaged in the absence of immediate climate stabilization.
Delta sustainability, River basin-delta connectivity, Delta sedimentation-enhancing strategies, Sea-level rise, Delta futures
