Mud on the move.

Abstract

Humans are reshaping the world9s mud supply, altering where—and how fast—it piles up. Thousands of years ago, our ancestors caused erosion rates to surge by starting to clear forests and plant crops, muddying lakes and rivers. Today, deforestation and urbanization are causing some rivers to carry more sediment, even as dams and efforts to curb erosion choke off sediment supplies to other waterways. Such changes, together with precipitation shifts driven by climate change, are leading to sometimes dramatic transformations in river deltas, coastal mud flats, and the amount of mud that ultimately collects at the bottom of the sea. Graphs, charts, and maps help tell this story.