1 / 25

Soil Erosion by Water

Soil Erosion by Water. AST 324 Carl E. Anderson. Chapter 6: Soil Erosion by Water: Learning Objectives. Understand the factors effecting the erosive force of flowing water Understand the factors effecting the forces resisting soil erosion

morag
Download Presentation

Soil Erosion by Water

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Soil Erosion by Water AST 324 Carl E. Anderson

  2. Chapter 6: Soil Erosion by Water: Learning Objectives • Understand the factors effecting the erosive force of flowing water • Understand the factors effecting the forces resisting soil erosion • Understand the basic procedures available for controlling soil erosion

  3. Soil Erosion • The gradual wearing away of the land surface by running water, wind, ice, or other geological agents. • Erosion is a natural process which can’t be stopped completely. • Some natural ecosystems depend on a natural rate of erosion.

  4. NATURAL EROSION

  5. Accelerated ErosionCAUSED BY • Overgrazing range and pasture • Cultivation • Construction • Heavy traffic on bare slopes • Maximum when bare soil is exposed during periods of maximum rainfall.

  6. SOIL EROSION PROCESSES • DETACHMENT • TRANSPORT

  7. Soil Properties Affecting Erosion

  8. Forces Tending to Cause Soil Particle Detachment • Raindrop impact • Forces of flowing water • Abrasive action of other moving particles • Weathering • Animal and human actions • Burrowing • Tillage • Excavation

  9. Soil Properties Tending to Resist Detachment • Adhesion • Cohesion • Binding forces of plant root systems • Protective coverings such as plant material

  10. Forces Tending to Transport Soil Particles • Raindrop splash • Forces of flowing water • Wind movement • Gravity

  11. Soil Properties Tending to Resist Transport • Inertia • High density • Large particle size

  12. EFFECTS OF RAINDROPS ON SOIL EROSION • Break up soil aggregates into small particles • Compact the soil surface and thus increase surface runoff • Splash small soil particles down the slope • Increase the turbulence of overland flow and thus increase the transport capacity of the flow.

  13. Raindrop Erosion

  14. Erosion Control Methods • Reduce Forces of Fluid • Reduce Flow Velocity • Increase Forces Holding Soil • Increase Adhesion • Increase Plant Root Structure • Separate Soil From Flow • Pavement • Mulch • Residue

  15. TYPES OF SOIL EROSION BY WATER • SHEET OR INTERRILL • RILL • GULLY • STREAMBANK

  16. SheetErosion

  17. Sheet and Rill Erosion

  18. Rill Erosion

  19. Gully Erosion

  20. Soil Loss Tolerance The maximum level of soil erosion that will permit a high level of crop productivity to be maintained both economically and indefinitely.

  21. SOIL EROSION UNITS • MASS PER UNIT AREA PER UNIT TIME • TONS PER ACRE PER YEAR • METRIC TONS PER HECTARE PER YEAR

  22. NATURAL EROSION RATE • 1 TO 5 TONS / ACRE / YEAR • Erosion Rates in this Range are Sustainable Indefinitely. • 1 ton / ac / year = 163 years / inch soil loss

  23. MAJOR FACTORS AFFECTING SOIL EROSION • Climate R • Soil K • Topography LS • Vegetation C • Conservation Practices P

More Related