Progress Article abstract
Nature Geoscience
Published online: 20 September 2009 | doi:10.1038/ngeo629
Sinking deltas due to human activities
James P. M. Syvitski1, Albert J. Kettner1, Irina Overeem1, Eric W. H. Hutton1, Mark T. Hannon1, G. Robert Brakenridge2, John Day3, Charles Vörösmarty4, Yoshiki Saito5, Liviu Giosan6 & Robert J. Nicholls7
Abstract
Many of the world's largest deltas are densely populated and heavily farmed. Yet many of their inhabitants are becoming increasingly vulnerable to flooding and conversions of their land to open ocean. The vulnerability is a result of sediment compaction from the removal of oil, gas and water from the delta's underlying sediments, the trapping of sediment in reservoirs upstream and floodplain engineering in combination with rising global sea level. Here we present an assessment of 33 deltas chosen to represent the world's deltas. We find that in the past decade, 85% of the deltas experienced severe flooding, resulting in the temporary submergence of 260,000 km2. We conservatively estimate that the delta surface area vulnerable to flooding could increase by 50% under the current projected values for sea-level rise in the twenty-first century. This figure could increase if the capture of sediment upstream persists and continues to prevent the growth and buffering of the deltas.
- CSDMS Integration Facility, INSTAAR, University of Colorado, Boulder, Colorado 80309-0545, USA
- Dartmouth Flood Observatory, Dartmouth College, Hanover, New Hampshire 03755, USA
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA
- Department of Civil Engineering, City College of New York, City University of New York, New York 10035, USA
- Geological Survey of Japan, AIST, Tsukuba 305-8567, Japan
- Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
- School of Civil Engineering and the Environment and Tyndall Centre for Climate Change Research, University of Southampton, SO17 IBJ, UK.
Correspondence to: James P. M. Syvitski1 e-mail: James.syvitski@colorado.edu