Developing Potential Of Gully Erosion And Distribution Relations Of Slope-gully Erosion In The Phaeozem Region Of Northeast China

The intensified development of eroded gullies in the black soil region in northeast China has created a fragmented surface morphology.The development of gully erosion has severely constrained the sustainable and healthy development of regional agricultural production,and the black soil land crisis is imminent.The eroded gullies complexity reflects the degree of regional ravines and gullies.The potential risk assessment of gully erosion classifies regional erosion status into different grades,which further clarifying the spatial distribution of gully erosion potential risk.The distribution relations of regional slope-gully erosion was discussed combined with the amount of hillslope erosion.This study has profound significance for understanding the evolution law of slope-gully erosion and for the purpose of assessing and controlling hillslope erosion and gully erosion in the black soil region of northeast China.In order to seek new ways to quantify morphological characteristics of eroded gullies,and to explore new ideas for potential risk assessment of gully erosion and systematic study of slope-gully erosion.This paper is based on the first national water survey data of eroded gullies census in the black soil region of northeast China.By means of remote sensing and GIS technology to analyze eroded gullies morphology characteristics,developing potential and distribution relations of slope-gully erosion.Firstly,the morphological characteristics of eroded gullies are quantified by using fractal dimension to determine the fractal scale-free interval,fractal dimension range and spatial variability of eroded gullies in the black soil region of northeastern China.The two-dimensional fractal theory is used to classify eroded gullies as linear and branch type.The representation of fractal dimension and the traditional quantitative indicators such as length,perimeter,area,density,intensity and vertical ratio were given by analyzing the correlation of them.Meanwhile,the developing potential model of gully network was used to establish indicators of density,intensity and land loss ratio,which found the gully erosion potential in the black soil region of northeast China has regional differentiation law by analyzing their current indicators and potential indicators.Through compared the potential indicators with the current indicators,it was found that the potential indicators are much larger than the current indicators in most cases,and gully erosion has sufficient space for development.For this situation,land loss ratio space was used to classify the study area as micro degree,slight degree,moderate degree,strong degree,great strong degree and severe degree of six dangerous area,and gave the assessment characteristic of each dangerous area.In terms of erosion way,hydraulic erosion is the main form of gully erosion in the black soil region of northeast China.Judging from the change of gully index in different landform types,the potential for gully erosion was the largest in Northeast China rolling hills sub-region and Changbai Mountain-Wanda hilly sub-region,which were the focus of future prevention and treatment.Finally,combining with the spatial distribution data of hillslope erosion in the typical rolling hills black soil area,USLE model and Kriging method were used to analyze the distribution condition of different erosion intensity,slope gradient and slope aspect,which clarified the main forms of slope-gully erosion in the typical rolling hills black soil area,the relations between slope-gully erosion,slope gradient and aspect,and found that the aspect was not the primary factor affecting the slope-gully erosion in the black soil region of northeast China.The critical indicators of slope-gully erosion comprehensive treatment were given by establishing the relations of hillslope erosion amount and gully erosion indicators.This paper main innovation lies in fractal dimension break through the limitations of traditional quantitative indicators,and provides new ideas for the systematic and scientific description of eroded gullies morphological characteristics.The developing potential model of gully network comprehensively considers the relations between critical gradient,erosion datum depth,balance transverse,hillslope catchment,test data,and field measurements on the vitality relations of eroded gullies formation,development and recession,which avoids the evaluation index factor-single of gully erosion in the past,so it has highly scientific.The system study of slope-gully erosion can determine the critical index of slope-gully erosion,which provided theoretical reference for the comprehensive treatment of regional slope-gully erosion.