GEOG M107 Lecture Notes - Lecture 3: Gully, Stream Energy, Surface Runoff
Document Summary
Erosion depends on: climate, vegetation, slope, soil material. Overland flow: surface runoff precipitation intensity > soil infiltration. Water concentrates into streamlets moves downhill (enough energy to scour small channels) Rills: much smaller, can parallel to one another and crop rows. Erode upward, amphitheater shape, larger than rills. Actively erode without vegetation, inactive erosion when vegetated. Caused by seepage and piping eroding internal material collapsing. As rivers meander, they get a lot of energy on bends (cut bank) a lot of erosion and deposit sediment on inside part of bind. Problem in dams: dams trap sediment water released below it is low in sediment water has a lot of energy erode downstream. Floodplain: can be scoured (cleansed) during floods new channels can form. Erosion result in lost soil, plant nutrients, productivity. Pollution and infilling of lakes, streams, and bottomlands. Best soil is usually on the surface. Organic material build up from dead plants.
