Impact of Humans on the Flux of Terrestrial Sediment to the Global Coastal Ocean
Abstract
Here we provide global estimates of the seasonal flux of sediment, on a river-by-river basis, under modern and prehuman conditions. Humans have simultaneously increased the sediment transport by global rivers through soil erosion (by 2.3 +/- 0.6 billion metric tons per year), yet reduced the flux of sediment reaching the world's coasts (by 1.4 +/- 0.3 billion metric tons per year) because of retention within reservoirs. Over 100 billion metric tons of sediment and 1 to 3 billion metric tons of carbon are now sequestered in reservoirs constructed largely within the past 50 years. African and Asian rivers carry a greatly reduced sediment load; Indonesian rivers deliver much more sediment to coastal areas.
- Publication:
-
Science
- Pub Date:
- April 2005
- DOI:
- 10.1126/science.1109454
- Bibcode:
- 2005Sci...308..376S
- Keywords:
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- OCEANS