Evaluation On Soil Erosion Control Effect And Soil Conservation Function Based On Landscape Structure

Because of concentrated rainfall and vegetation destruction the Loess Plateau which covered the deep loess layer by has become the most serious area of soil erosion in China.Serious soil erosion not only destroys vegetation and aggravates drought and flood disasters,but also affects the local people’s life and production and restricts the economic development.So,the study of soil erosion control and soil conservation service is of great significance,which also help to improve the ecological situation and promote the ability of the ecosystem service.Soil erosion process is a spatial distributed process,which is deeply influenced by topography structure and land use/cover pattern.It is of great significance to incorporate the influence of landscape structure into the estimation of soil erosion.By taking in the index of connectivity,the paper develop a method which can enhance the mechanism of sediment transport,couple the soil conservation service supply and demand and be applied to the assessment of soil conservation services in the watershed.By the method of field experiments and simulation calculations,this paper research the relationship between sediment yield and index of connectivity.The result show that index of connectivity has a positive correlation with soil erosion in the same vegetation condition,can reflect the change of soil erosion in a certain extent.The validity of soil erosion was verified by sediment connectivity.By using remote sensing images,land use maps,DEM maps,meteorological data,soil data and statistical data,the changes of sediment connectivity in the Yanhe River Basin in 2006,2012 and 2016 were calculated under the support of ArcGIS software,and analyze the spatial and temporal dynamics of sediment connectivity in the basin.The results show that the total vegetation coverage in the catchment become higher and the overall runoff and sediment reduction effect is enhanced.From the point of view of soil conservation service income area,only the index of connectivity between grassland and pond and construction land is increasing,and the index of connectivity of other vegetation types to soil maintenance service areas are all decreasing.As a whole,resulting in the decrease of average index of connectivity,the average index of connectivity of vegetation construction area to farmland,reservoir and construction land has been decreasing.From 2006 to 2012,the policy of returning farmland to forest and grass was carried out in the basin range.The grassland was transferred to forest and shrub.The area of grassland was greatly reduced.The sediment connectivity of the grassland to the reservoir and the construction land was increased,but the total vegetation coverage in the basin was higher,and the effect of sediment reduction and sediment reduction was strengthened.All index of connectivity is reduced.Watershed scale local soil conservation estimation and soil conservation service transfer assessment.By analyzing the change distribution of soil conservation in the vegetation construction areas(forests,shrubs and grasslands),the change of the supply capacity of soil conservation service was explored.As the total area of forests and shrubs increased,their ability to maintain soil services was increased,while the ability of grassland to maintain service supply was decreasing.The soil maintenance service volume of the vegetation construction area to farmland increased first and then decreased,and the soil maintenance service quantity to the pond and construction land continued to increase.The method connects the supply of soil conservation service and the service demand of soil conservation in the basin,and realizes the quantification of the transport of soil conservation service space.The conclusions can provide important support for the study of soil mobility and the coordinated development of regional ecological environment.