One mining camp was dumping tons of sediment into a tributary of the Yellow River within sight of police patrols and near a large highway sign that proclaimed the river a " land and river erosion protected area ."
32.
Stream restoration can include such things as removal of encroaching species of plant from streambanks, construction of retaining walls to prevent river erosion due to human use, and construction of weirs or small water breaks to provide trout habitat where none existed before.
33.
The walls help to stabilise and deepen the channel which benefits navigation, flood management, river erosion and water quality but can cause coastal erosion due to the interruption of longshore drift . One solution is the installation of a sand bypassing system to pump sand under and around the entrance training walls.
34.
However, while many ( but not all ) canyons are found offshore from major rivers, subaerial river erosion cannot have been active to the water depths as great as 3000 meters where canyons have been mapped, as it is well established ( by many lines of evidence ) that sea levels did not fall to those depths.
