Dynamic Study Of Soil Conservation Quantity And Function Based On CSLE Model In Yimeng Mountain Area

Yimeng Mountain Area is located in the low hilly area of central Shandong in the northern earth-rock mountainous area.It is an important production base for grain and oilseeds in Shandong Province.This area has a high land reclamation rate in history,bare mountain base rock,barren soil,few natural vegetation distribution,poor forest structure,low vegetation coverage,poor soil conservation capacity,and serious soil erosion.The main part belongs to Mount Tai-Yimeng national key soil erosion prevention areas.In the three-level zoning system of "National Water and Soil Conservation Regionalization(Trial)",soil conservation is the dominant basic function of soil and water conservation in this area.In recent years,national and regional ecological environment construction has been strengthened,and the deployment of key soil and water conservation projects has increased.In the Yimeng mountain area,small watersheds have been used as a unit to implement measures such as returning farmland to forest land,closing and replanting,and carrying out projects such as slope conversion projects.The effect of reducing soil erosion in the area is obvious,improving the effect of soil erosion prevention and control and ecological benefits.Therefore,this study takes 27 counties(cities,districts)in the Yimeng mountain area as the study area,mainly land use types as the research object,and uses remote sensing and geographic information system technology.Image extraction,data collection,model calculation and other methods to carry out research on soil conservation and function dynamics based on CSLE model in the Yimeng mountain area.In this way,it reveals the spatial pattern and dynamic characteristics of land use in the Yimeng mountain area,clarifies the relationship between the spatial pattern of soil conservation and land use,and explores the value evaluation of soil conservation based on the equivalent factor method.The results are expected to provide reference and basis for optimizing land use structure,and improving soil conservation and functional value in Yimeng Mountain area.The main conclusions are as follows.(1)Spatial pattern and dynamic characteristics of land useAmong the land use types in the Yimeng mountain area,farmland accounted for the largest area in 2007 and 2017,more than 50% of the study area.Followed by forest land,construction land.Various land use types in the study area have changed to varying degrees in the past 10 years.In 2017,the area of farmland,grassland and other land is decreased,the area of construction land,waters and forest land is increasing.In spatial distribution,farmland is widely distributed throughout the district,and forest is mainly concentrated in Yiyuan County,Yishui County,Mengyin County and Wulian County;grassland is scattered;construction land is distributed in all counties,with Donggang District and Tengzhou City accounting for the majority The waters are mainly distributed in Weishan County;other land is more in Yishui County,and the rest of the counties are scattered.In 2017,The comprehensive change of land use in Lanling County is remarkable,a large area of forest was transferred to farmland in Lanling County.The increase in forest land was mainly in Yiyuan County,Mengyin County,and Feixian County,the increase in construction land mainly occurred in Fei County,Donggang District and Ju County.(2)Spatial pattern and dynamic characteristics of soil conservationOn the whole,the amount of soil conservation in 2007 was 610.36 million tons,increased by 2.9529 million tons from 2007 to 2017,and the highest amount of soil conservation per unit area is in other land,the amount of soil conservation per unit area of forest land,farmland,grassland,construction land,and waters decreased in proper order.In 2017,grassland,other land,forest land,and waters increased,while the amount of soil conservation per unit area of farmland and construction land decreased.In spatial distribution,the amount of soil conservation shows an increasing trend from areas with flat terrain to areas with large slopes such as the southwest and the north.High values are concentrated in Yishui County,Yiyuan County,Mengyin County,Feixian County,low values are concentrated in Weishan County,Lanling County,Tengzhou City.(3)Soil conservation function value and dynamic characteristicsThe soil conservation function value is estimated based on the equivalent factor method,and the multi-year average net profit of wheat and corn in Shandong Province from 2007 to 2017 is used as the basis for calculating the value coefficient.The soil conservation function value of Yimeng Mountain area in 2007 and 2017 was 14.949 billion yuan respectively,17.132 billion yuan,the soil conservation function value produced by forest land is the main source of soil conservation function value of the ecosystem in the Yimeng mountain area,followed by the soil conservation function value of farmland.From 2007 to 2017,the value of soil conservation function increased by 2.183 billion yuan,of which the main value increment occurred in woodland,grassland and water areas.The value of soil conservation function of farmland decreased significantly due to the decrease of farmland.