Studying On Process Of Erosion-deposition On Eastern Slope Of Great Khingan And Its Indicative Significance

Basin-mountain coupling and the uplift and denudation process of mountainrange has become one of the hot areas of contemporary research in academia, thecoupling of basin-mountain’s erosion and deposition and the adjacent sedimentarybasins of orogenic belt record the history of mountain uplift and erosion truly. Therelative raised mountain is crustal uplift area, the dominated landscape is denudation;and the plain is relatively stable or sedimentation area, it is dominated by theaccumulation process. In order to characterize this transported deposit process oferosion-sediment substances of mountain soil accurately, this paper builds themountain soil erosion-sediment model. There are denudation of provenance andsedimentation of depositional district (or basin) in any valley, which make up therelatively independent erosion-sediment system. In this system the main transmissionmedium is river water. So, the study for an erosion-sediment of a large mountain orplateau river gives a new clue to understand the formation of mountain andsedimentation mechanism of basin. Greater Khingan is the watershed of the InnerMongolian Plateau and the Northeast Plain, the research for erosion and depositionprocess of the eastern slope has indicative significance for the division of GreaterKhingan and the Northeast Plain.Taoer River, Yalu River and Gan River are the study areas, the landscape is fromthe plains to the mountains, it is also the transition zone from the Northeast Plain toGreater Khingan. This paper collects the climate data, terrain data and physical andchemical properties of soil type and land use data and the crop managementinformation, then establishes the database the Water Erosion Prediction Project(WEPP) needs.This article analyzes the existing erosion-deposition process and summarizes thesoil erosion models home and abroad, then selects the Water Erosion PredictionProject (WEPP) to divide Greater Khingan and the Northeast Plain quantitatively. TheWEPP model needs the establishment of four basic databases to run: climate, soil,slope and crop management. According to the data of daily rainfall, maximum andminimum temperature, the climate database of study area could be established byselecting the US referential stations, on the basis of climate analogy principle. In accordance with the ASTER GDEM data and hydrological analysis method the slopedatabase can be established, and then the crop management database can be built withthe land use classification data, finally by analyzing the soil types and its physical andchemical parameters data the soil database can be set up.According to the rule of erosion and deposition amount and terrain factor, thispaper gets the relationship of the erosion-sediment equilibrium point and terrain factor(slope and slope length), then extracts erosion-sediment equilibrium points of3valley,and finally divides Greater Khingan and the Northeast Plain quantitatively. By meansof reviewing the research progress of China landform classification and summarizingthe experiences of previous landform classification system, combined with thelandscape features of Greater Khingan and the Northeast Palin, this paper forms a newlandscape classification scheme: elevation and slope grading scheme, and extracts theboundary line base on the new classification scheme. The boundary is clearly visibleand distinguishes Greater Khingan and the Northeast Palin clearly, in the mean timethe elevation reclassification map of study area and the Chinese ground elevationaltitude spatial analysis chart by means of the China National Digital ElevationModel(1:1000000) prepared by200m and250m mainly consistent with this area.Finally, according to the result of qualitative division this paper verifies thequantitative division result of Greater Khingan and the Northeast Plain.China is low-lying west to east, almost to the ladder-like distribution,“ThreeGradient Terrain” is the general description of the country’s terrain fluctuation, whichdepicts the general characteristics of Chinese topography changes accurately andvividly, however three steps for the specific boundary description is only qualitative,not quantitative. Traditionally, the northeast boundary of second-third step is definedby Greater Khingan, so dividing Greater Khingan and the Northeast Plainquantitatively has indicative significance for the extracting the partial boundary ofsecond-third step.