|Title||Control of erosion and sedimentation by treatment of arid rangeland|
|Publication Type||Conference Proceedings|
|Year of Publication||1980|
|Authors||Tromble J.M., Wood M.K|
|Conference Name||Proceedings of the Second International-American Conference on Salinity and Water Management Technology|
The number one pollutant of the waters in the United States, by volume, is sediment. Annual sediment deposition is estimated at 10,489 x 105 m3. Rangeland treatments such as vegetation manipulation by mechanical and chemical treatments are ways of controlling and regulating surface runoff, reducing sediments and increasing water quality. The presence of vegetation can affect infiltration by reducing the direct impact of raindrops on the soil surface which reduces erosion and sediment loads.
Studies have shown that several factors can affect water yield and sediment production such as storm intensity, watershed size, and soil surface microrelief. Other important factors are soil depth and water storage capacity, rainfall amount and distribution, infiltration rates, and the type of vegetation, before and after site conversion.
Measurements of soil surface characteristics indicate a significant reduction in surface runoff with increased amounts of erosion pavements. Mechanical treatment is important in converting rangeland infested with shrubs to grass and is a prime consideration in controlling runoff and erosion and, reducing sediments. Ripping and seeding an area to grass and browse species reduced runoff by 97 and 83 percent the first and third years following treatment.
Also erosion was reduced 86 percent and 30 percent, the first and third years, after the ripping treatment. Contour furrowing retains water at onsite locations and significantly reduces surface runoff. Pitting significantly reduced runoff when compared to a control treatment. No significant differences were noted between pitting and rootplowing treatments. Additional detention storage is provided by pitting and rootplowing treatments although smoothing of the soil surface with time was very apparent for both treatments. Infiltration increased and subsequently runoff and erosion decreased after approximately four years following rootplow and seeding treatments