The Study On Soil Wind Erosion Of Different Land Uses In Bashang Area,Hebei,China

The Bashang area,Hebei,China is in the center of the northern ecotone,where the soil erosion is serious and the ecological environment is fragile.And it is one of the important ecological functions of Beijing and Tianjin.The native vegetation in the Bashang area was temperate grassland.With the cultivation of farmers,the area of farmland was expanding and the area of grassland had dropped sharply,which leaded to the deterioration of ecological environment and serious wind erosion.Since the 1970 s,a series of ecological restoration projects have been implemented,such as the Three North Agroforestry Systems,Beijing and Tianjin sandstorm source control project and the Returning Farmland to Forestry and Grassland.Because of the implementation of ecological engineering,the land use mode of Hebei Bashang area showed a diversified structure,and it is a prerequisite for scientific improvement of ecological environment from full understanding of the change of land use patterns.In this paper,we chose three representative test plots,which are basically different from each other in terrain and climate in Bashing area,Hebei.Sample plot 1 includes natural grassland,farmland and returning farmland to forest land;Sample plot 2 includes natural grassland,farmland and returning farmland to shrub land;Sample plot 3 includes farmland,returning farmland to forest land and returning farmland to shrub land.The native vegetation is natural grassland,which was reclamed to the farmland in the 1950 s.After the 1980 s,with the construction of the Beijing-Tianjin sandstorm source,the farmland was returned to forest land and shrub land.Based on the field investigation and laboratory analysis,we observed and analyzed the transported sediment,aerodynamic roughness and the soil physical and chemical properties of different land use patterns in Bashing area,Hebei,which include natural grassland,farmland and abandoned lands.And we explore the different land use patterns of the wind erosion effect,the results showed that:The surface soil water content,hardness and the content of organic matter are as follows: The amounts are followed from high to low by natural grassland,farmland and farmland.The returning farmland to forest land is higher than returning farmland to shrub land.The grain size composition is as follows: the content of fine particulate matter in the surface soil is followed from high to low by natural grassland,abandoned farmland and farmland,and the coarse matter of the surface soil is followed from low to high by natural grassland,abandoned farmland and farmland.it the content of fine particulate matter in the surface soil of returning farmland to forest land is higher than that of returning farmland and shrub land,and the content of coarse particulate matter is lower than that of returning farmland to shrub land.The aerodynamic roughness is as follows: the dynamic aerodynamic roughness is followed from the high to the low by natural grassland,abandoned land the farmland.The dynamic aerodynamic roughness of returning farmland to forest land is higher than returning farmland to cultivated land.The sediment transport capacity is as follows: the amount of sediment is followed from low to high by natural grass,abandoned farmland and farmland.The returning farmland to forest is lower than the returning farmland to shrub land.