Study On Soil Erosion Evaluation Of Slope-Small Watershed-Watershed In The Central Mountains Area Of Shandong Province

Luzhong mountain area is located in the hinterland of Shandong province,where the terrain is relatively high.The terrain is mainly mountainous and hilly,the surface is changeable,the ecological foundation is fragile,the rainfall is concentrated,and the soil erosion is serious.The problem of soil erosion seriously affects the local ecological environment and the development of agriculture,industry and other economic industries.Therefore,the study of soil erosion evaluation index is of great significance for the protection of local economy and industry and the formulation of soil and water conservation strategies.Based on in rainfall,DEM,land use,soil,such as remote sensing image data,through the ArcGIS platform in the stack,grid computing,such as spatial analysis technology,calculating the area rainfall erosivity factor(R),slope length,slope factor(LS),soil corrosion factor(K),vegetation coverage factor(C),and other factors in the process of soil erosion.And based on the multi-scale soil erosion evaluation model proposed by Fu Bojie and considering the natural environment factors in the central shandong mountain area,the soil erosion model and soil erosion evaluation index were constructed at three scales of slope,small watershed and watershed.The main research results are as follows:1.Under the slope scale,the order of vegetation cover from top to bottom is changed,and the evaluation index of each order is obtained by using the soil erosion evaluation index model under the slope scale,and then the optimal land use form is obtained.The slope types can be divided into three types.The slope of the first type is unchanged,and the optimal land use form under the slope of 10°,15°,20°,25° and 30° is obtained respectively.The second slope is 10°,15° and 20°.The three slopes are the planting of crops and cash crops.There are 8 slope combinations and 3 types of land use and optimal land use form is obtained synthetically.The third one is that the slopes of five slopes are arranged in sequence,and the slope decreases from top to bottom,which is in line with the characteristics of large slope variation and single terrain in hilly and mountainous areas,and the optimal land use form is obtained according to the soil erosion evaluation index.2.At the small watershed scale,there are four small watersheds,each of which has two parts: erosion area and water area,and the land use types in the erosion area are intricately distributed and the topography varies.In addition to rainfall,soil,vegetation coverage and slope factors,distance index should also be considered,and the soil erosion evaluation indexes of the four small watersheds are obtained by using the model: 0.5494,0.4956,0.2655 and 0.2620,respectivelyBased on the characteristics of soil erosion evaluation index and the topography and land cover of each small watershed,the following conclusions are drawn:In order to reduce soil erosion,the distribution of cultivated land should be in hilly and mountainous areas within the range of soil and water conservation measures,such as plain areas or terraced fields.Vegetation cover in hilly mountain areas is primarily considered woodland,as this land use type has good effect of soil and water conservation.Construction land itself will not occur soil erosion,and it has a good barrier effect for soil erosion process3.At the watershed scale,the study area is larger,involving most areas of Weifang,Tai'an,Linyi,Zibo and Jinan.It is divided into these basins ofYufu river,Yi river,Zi river,Xiaofu river,Mi river,Weihe river,Baluo river,Shuhe river,and Mouwen river.According to the soil erosion factors and distance indexes,the soil erosion evaluation indexes of each river basin are 0.2306,0.4481,0.2934,0.5503,0.3842,0.6117,0.3863,0.6837 and 0.3945,respectively.Among them,the soil erosion evaluation index of Yufu river basin and Zi river basin is small,both less than 0.3,and the overall soil erosion is not obvious;The soil erosion evaluation index of Mihe river basin,Baluo river basin,Mouwen river basin and Yihe river basin is between 0.3 and 0.5.Some areas of these basin can take appropriate targeted measures of soil and water conservation;The soil erosion evaluation index of Xiaofu river basin,Weihe river basin and Shuhe river basin were all greater than 0.5,and the soil erosion is the most serious.Therefore,funds and scientific and technological investment can be increased in the work of soil and water conservation in this region.