Study Of Soil Erosion Quantitative Analysis Based On Remote Sensing And GIS Technology In Panshi City

Soil erosion is one of the most serious nature disasters. According to thefirst of national soil erosion investigation , the area of low-grade water andwind erosion is about 367 ten thousands kilometers ,which equals to 38.2percent of territorial areas. Water erosion is mainly in the east , wind erosion ismainly in the northwest , freeze-thaw erosion is mainly in Tibet altiplano , allof the types of erosion , the water erosion is the most serious , that is mainly inthe loess plateau, Yungui plateau, earthy mountain area of north, south hillyarea and northeast blackland. The serious soil erosion can destroy theentironment , deteriorate the water and soil resources, endanger the farmland,infect the agricultural production, silt the river and reservoir, reduce the benefitof engineering and the ability of resisting disaster etc. So the effectivemanagement is needed urgently in waterpower erosion region at present.At present there are two ways of soil and water loss, one is groundinvestigation ,the other is qualitative remote sensing method. Although the twomethods can obtain the predictive map and the correlative statistic dataaccording the technical regulations, it is hard to meet the need of timing anddynamic soil erosion because of subjectivity and huge human power andmaterial resources. With the development of modern science technology, thereare many applied tools to count the soil erosion for us, GIS is one of the mostpractical software. We can build digitized data base according to the functionof GIS system supplied , that include geometric futures of one of cartographycells(area, girth, position of geometric points);types of soil erosion, intension,extent;charts of soil erosion, charts of soil utilize and image libraries. Atpresent we always apply GIS technology to quantitative analysis in the studyof soil erosion in many drainage areas, this method is not only shortcut andnicety but also the data can be updated at any moment , it offers the possibilityfor us in the study.This study uses quantitative remote sensing method on soil erosion whichsupported by GIS software in Panshi city and probes into the soil erosionprediction model and all parameters to adapt to this region and discusses theprinciples of geographical database .we also discuss whether this method is fitfor the practice.In the thesis papers, we introduce the existent problems, study ways, themain content of this thesis and the course of technology in the first paper;inthe second paper we know the research and evolvement of soil erosion and theexisting states of soil erosion quantitative analysis model and the characters ofsoil erosion info system;in the third paper we introduce the model andalgorithm of every genes and the principle of soil erosion by remote sensing;in the fourth paper we build the soil erosion geographical database and DEM,and based on this have spatial analysis we obtain the map of R,K,LS of ourregion and the map of C by using quantitative remote sensing method;in thefifth paper we have some conclusions and advices ,so we get the gross of soilerosion and the map of values and analyse the appropriator, existing problems,dynamic and the foreground of this method.The study is composed of annual soil losses monitoring model andalgorithm of every genes and the software based on the remote sensing theoryand the remote sensing theory of soil losses. We turn the original data tonumeralization and grid and be matched with DEM which by investigation ofthe field spots and analysis of soil's physicochemical property indoor and byusing of the remote sensing data and some information of terrain,soil,landuseand rainfall. In this study we built soil erosion geographical database andworkout all genes maps of loss equation to built the soil erosion monitoringinfo system. A map of erosion modulus spatial distribution was obtained andapproved effective based on the soil erosion model and parameters , this resultthat combination of soil erosion quantitative prediction model and spatialanalysis in GIS can fulfill the task of soil erosion quantitative prediction in abig region ,and that quantitative remote sensing can obtain the plant coverparameters needed for the model effectively and provide a more accurate andfaster approach than conventional monitoring method. Besides the functions ofdata entering, processing, querying, statistic and printout, the system in thisstudy includes the function of spatial analysis. This can satisfy the need ofactuality investigation and dynamic prediction and command the space-timeregulation , this also can be provided scientific base for soil erosionmanagement. So this method has practicability and adaptability in this regionand has wide application future. But the quantitative analysis model is aintelligent statistical model, it must base on long period and systemicobservational data of soil losses, so it has restricted by all kinds of factors. Thedata are not enough to build the quantitative analysis model in this study andaffect the precision and applicability of the results in the certain extent. Asbeyond the confines of studying time and the level, there will be more worksto supply and perfect in the future.