The Study On The Characteristics And Mechanism Of Gravity Erosion In Lintong Lishan

Gravity erosion is a type of soil erosion. For a long time, due to random and non-continuous of gravity erosion, making the study on gravity erosion lag relative to water erosion;Lintong Lishan's gravity erosion is more serious for its unique landforms;Lishan is not only a major tourist destination integrating the natural landscape and human landscape in one, but Lishan has mountain villages where many villagers engaged in agricultural activities, therefore, Lishan is a hot spot of human activity.Lishan's gravity erosion not only harms local ecology and the environment, but threaten the lives of people and property;the study on Lishan Region's gravity erosion is almost empty.Therefore, the subject selects the reserch of basic features of gravity erosion in Lishan area,revealing the related factors affecting to Lishan's gravity erosion,analyzing how these factors play a role in gravity erosion,interpreting the gravity erosion mechanism of Lishan.This study can not only enrich the basic research of gravity erosion, but also has an important reference value for Lishan soil erosion disaster prevention.The basic characteristics of gravity erosion determine its basic data is difficult to effectively get through fixed-point observation method.Therefore, the main research method used in this study is a classic study methods of physical geography-field investigation method.By designing typical expedition route in the study area to obtain a sufficient amount of gravitational erosion samples,and to record the basis relevant data about these samples, including topography, geological structure, formation time, and gravity erosion point's coordinates, elevation, type, size, and so on.After the completion of field work, combined with remote sensing image data, DEM data, geological maps,deal with the data through GIS platform software, such as entering, editing, processing, analysis and visualization,get all kinds of useful information of Lishan gravity erosion. I give the following main results or conclusions through a comprehensive analysis of the surveyed data and related data.(1) The gravity erosion in Lishan is divided into three types, namely, collapses, landslides and diarrhea slip. According to the difference of the erosion material, the three kinds of erosion are subdivided into six categories, which are respectively rocky collapse, soil collapse, rocky landslide, soil landslide, sandy diarrhea slip and soil diarrhea slip.(2) The gravity is the direct cause of the gravity erosion, and many other factors provide conditions for gravity's action, these factors can be divided into two categories, namely, the dominant factor and inducible factor.(3) In this study, I have a detailed analysis to the role of various types of dominant factor and inducible factor in gravity erosion, and identify the most dominant factor are the material structure factors(including joints and bedding), high dominant factor are the material property factors(mainly refers to lithological or soil texture); the strong inducible factor is weathering and road construction. It is considered that the gravity erosion is types of soil erosion based on the internal factor, and the external factors playing the key role.(4) Using the method of statistical analysis, I analyzed and summarized the quantitative, scale and distribution characteristics and so on about Lishan's gravity erosion. The quantity characteristic of Lishan gravity erosion is collapse> diarrhea slip> landslide, and the rocky collapse is the most, the rocky landslide is the least.The scale characteristic of Lishan gravity erosion show that the scale span is very large among different kinds of gravity erosion;soil landslide is the most widely distributed gravity erosion type in Lishan;compared to the volume of the scale: rocky collapse>sandy slide>soil collapse>soil diarrhea slip, and the total amount of rocky collapse is far greater than the soil collapse, the total amount of sandy diarrhea slip is far greater than the soil diarrhea slip.The distribution of gravity erosion in Lishan, in the vertical direction, the distribution of height overall performance as soil diarrhea slip>sandy diarrhea slip>rocky landslides>rocky collapse>soil Landslide>soil collapse.The soil collapse is mainly in the low altitude, soil collapse and rocky collapse are mainly in the middle elevation,sandy diarrhea slip and rocky collapse is mainly in the high altitude.The horizontal distribution characteristics overall performance as that rocky collapse, sandy diarrhea slide and rocky landslide are mainly distributed in the mountainous landform of Lishan,and the soil collapse, soil landslide and soil diarrhea slip are relatively scattered in the spatial distribution and throughout the study area.Regions that mountainous terrain transit to hilly terrain are the soil erosion-prone areas.Scale distribution of performance as the scale of gravity erosion is not large in the central part of the Lishan,the larger areas are mainly distributed in the regions where mountainous terrain transit to hilly terrain,or in the regions where mountainous terrain transit to flood plain;in addition, both sides of the road are all kinds of erosion-prone area,the mountain valley location always have serious rocky collapse,the upper reaches of the river on both sides are the most common location of sandy diarrhea slip and soil landslides.The types of gravity erosion in Lishan area have different disaster characteristics,which is mainly based on the rocky collapse and soil landslide.Finally, this research puts forward countermeasures to prevent and control the gravity erosion disaster in Lishan.