Study On The Effect Of Grass Cover On Soil Loss In Typical Area Of The Loess Plateau Based On The Runoff Plot Data

Loess Plateau is a region with relatively serious soil erosion in China.Therefore,it is also one of the areas where water and soil conservation research is most concentrated in China.The effect of vegetation coverage factors on water and sediment reduction is also an important part of related research.However,due to the vast area of the Loess Plateau,erosion is concentrated in one or more rains.Thus,the researches of effects of vegetation measures on water and sediment reduction are mostly based on sub-rainfalls or artificial rainfalls,and most of them are based on individual sites.Moreover,the quantitative study on the benefits of vegetation measures for sand reduction under natural rainfall conditions on regional scales is still insufficient.The lack of it has,to a certain extent,limited the accurate knowledge of the benefits of vegetation reduction in the Loess Plateau.C values refer to the ratio of the amount of soil loss with vegetation cover to the amount of soil loss without vegetation cover under the same conditions,and its value is between 0 and 1.C values can be used to represent the benefits of sand reduction under different vegetation coverage.In this study,the basic data of forest-grass plot in different area of the Loess Plateau was collected and a database of the Loess Plateau plot information was established.Finally,Observing comprehensive standardized management and typical representative data of four groups of grassland vegetation in Huangfuchuan,Nanxiaohegou and Ansai were selected.Based on this,we established the following relationship between the coverage and the C values of grassland in the Loess Platea:.C=-0.337 ln(v)+1.5412In which,C is the coefficient of vegetation effect,dimensionless;v is the coverage of grassland vegetation(%).After obtaining the relationship between the coverage and the C-value,conduct analysis and verification.We can see that,on the one hand,through comparison and verification,it can be found that the coverage and the curves of C values obtained by this study are basically consistent with the curves of Zhongshan Jiang,Juying Jiao,Yunxi Xiong,and Bin Liu;on the other hand,the C values obtained in this study are basically consistent with the C values obtained from the long-years' rainfall data of other runoff communities in Lishi,Tianshui and Ansai in other typical areas of the Loess Plateau.Therefore,the relationship between grass coverage and C values obtained in this study is higher and the applicability is wider.The results of this study are of great significance for predicting soil erosion in the Loess Plateau and evaluating the effectiveness of ecological management of soil and water conservation in the Loess Plateau.