Wiki has a ton of info on the natural erosion process.
Some very interesting stuff, IMO.
https://en.wikipedia.org/wiki/Erosion_%28geology%29
Contents
1 Physical processes
1.1 Rainfall and surface runoff
1.2 Rivers and streams
1.3 Coastal erosion
1.4 Chemical erosion
1.5 Glaciers
1.6 Floods
1.7 Wind erosion
1.8 Mass movement
2 Factors affecting erosion rates
2.1 Climate
2.2 Vegetative cover
2.3 Topography
2.4 Tectonics
3 Erosion of Earth systems
3.1 Mountain ranges
3.2 Soils
4 See also
5 References
6 Further reading
7 External links
https://en.wikipedia.org/wiki/Erosion_%28geology%29