The way rivers function is significantly affected by how much sediment they transport and where it gets deposited. River sediment — mostly sand, silt, and clay — plays a critical ecological role, as it provides habitat for organisms downstream and in estuaries. It is also important for human life, resupplying nutrients to floodplain agricultural soils, and buffering sea level rise caused by climate change by delivering sand to deltas and coastlines. However, these functions are under threat: in the past 40 years, humans have caused unprecedented, consequential changes to river sediment transport, according to a new study.
