| Soil wind erosion can cause land degradation, land desertification andsandstorms which are the most serious environmental problems in recent years in thenorthern farming-pastoral areas of and even become a major ecological environmentproblem and one of the socio-economic problems in north of China. More than90%of the grasses in Hebei Province have been more or less degraded. This phenomenonnot only constrains the development of livestock, but also created a threat ofecological security in Hebei Province and Beijing-Tianjin region due to the decline ofeffect of grassland preventing the wind invasion. Since the year2000, Bashang areaimplemented the project of reducing cultivated land for green grass. Some place hasbeen improved, but the speed of governance cannot keep up the speed of destruction.Desertification in this region is still worrying.This article chooses KangBao county of Hebei Bashang area as a typicalfarming-pastoral area. I adopt the methods of observation of field and the combinationof wind tunnel simulation. Through the analysis of the organic matter of soil, theroughness of the earth’s surface and the amount of wind erosion of the different typesof grass and the comparison of farmland, this article researches the wind resistance ofgrass, reveals the effect of wind erosion prevention, and concludes that the trend ofdevelopment of the grass. At the same this article time provide the theory basis forKangBao country to the prevention of soil erosion.The results show that:(1)There are relationships among the soil organic matter, the type of grass andthe depth of the soil. The higher of the grass coverage is, the smaller of the winderosion modulus is and the higher of the soil organic matter is; Surface soil was easilyerosion by wind, the speed of soil degradation is fast and the speed of depth soildegradation is relatively slow; Plant roots group of underground which can fix the soil,improve the structure of soil, fix the nutrient and improve the content of the organicmatter is densely; Different grass types have different grazing intensity, which not only has the influence of the ground part, bus also had the influence of undergroundand the content of soil organic matter.(2)There are obvious relationships betweenthe content of soil organic matter and conditions of the earth surface. The content ofsurface soil organic matter is higher than the surface of the bare soil organic matter.(3)There are close relationships between the soil erosion and roughness of theearth surface. The changes of the surface roughness is to seal the grass> artificialgrass surrounded> natural grassland, when the coverage in70%or even higher, thegrass can prevent soil erosion.(4) The height of crop plants is different, the angle of the wind and planting isdifferent, and wind erosion strength is different. The height of crop plants increased,the soil erosion modulus show descended trend. The bigger of the angle of the windand planting is, the smaller of the soil erosion is. Therefore, in the process of forestand grassland construction should take artificial vegetation planting plant relativelyhigh grass seed, and plants should be and the wind to planting vertical to reduce winderosion intensity.(5) Wind tunnel test concludes: There are negative correlation between theintensity of grass wind erosion（Qt）and the roughness of the earth surf ace. And thereare positive correlation between the intensity of grass wind erosion（Qt）and the windspeed. Establish the relationship model of the wind speed and the strength of winderosion: Qt=k exp (b V)... |
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