Soil Erosion Prediction And Design Of Soil And Water Conservation Measures Of Yibi Highway

At present, soil erosion has become a serious global environmental problem.Soil erosioncan lead to a decline in land productivity, sediment deposition of rivers, lakes and reservoirs,and it is also an important cause of water pollution.Development and construction projectscan cause severe soil erosion,so prevention and control of soil erosion become thereforeimminent.For soil erosion, prediction is the basis of control.This study systematically introduced techniques of soil erosion prediction andprevention.It took Yibi highway as an example to give a pridiction of soil erosion and adesign of protection measures.In this paper,the major results were summarized as follows:(1)The pridiction of disturbed surface area of the project is819.11hm2and the damagedfacilities area of soil and water conservation measures is456.74hm2;It may totally produce801170.75t soil erosion,and the additional soil erosion amount is755237.68t.(2)According to the characteristics of soil and water erosion of the project, the papertook comprehensive measures which included engineering measures、plant measures andtemporary measures, to reduce soil erosion. Engineering measures included1568m retainingwalls of stone masonry,18580m drains, tillage recovery of40.72hm2,34stilling hom,3726.50m3filter layer; Implement area of plant measures was149.15hm2. Bridge and culvertproject restore vegetation through the creation of a single tree species with a2m×2mspacing.Revegetation measures of other areas were to create mixed forests, which mixedbetween lines, with a1:1ratio and a2.5m×1.5m spacing. According to statistics,we need45907Alnus nepalensis D.Don seedlings,86790Salix matsudana Koidz seedlings,195482Semen Cajani Cajani seedlings,175540Vitex negundo Linn seedlings,2859.9kg Eremopogondelavayi A．Camus seeds,565.2kg Lolium perenne seeds and1049.4kg Trifolium repens Linnseeds.Temporary measures included47900m retaining wall of soil bags,6500m gabionretaining wall,62690m temporary drains,203temporary grit chamber and82000m2temporarycoverage.(3) After the effective implementation of soil and water conservation measures,thefollowing objectives will be reached: a98.75%remediation rate of disturbed land, a97.31%soil erosion governance area rate, a97.74%dregs–retainingrate rate, a99.90%vegetation recovery rate,a40.11%forest coverage rate and a1.04ratio of allowable soil erosion intensityto soil erosion intensity after implementation of soil and water conservation measures.Theimplementation of soil and water conservation measures of the project will greatly control thesoil and water erosion and the benefit of social and environment is very significant.