Construction And Application Of Engineering Geological Environment Evaluation System In The Lower Reaches Of Tumen River Based On RS And GIS

Basically,under the background of North Korea's gradually opening political and economic policies as well as the "The Belt and Road" strategy strongly advocated by our country,the economic construction in the northeastern border region of our country is about to usher in unprecedented development opportunities.Among them,as the border area between China,North Korea and Russia,the lower reaches of the Tumen River have unique investment and development prospects.With the rapid development of 3S technology,engineering geological evaluation,which is characterized by the combination of remote sensing geological survey and geographic information system analysis,can provide early planning guidance and basic reference materials for engineering construction projects.Based on the "Basic geological survey of northeast border area" and "Natural resources renewal investigation project of Liao,Ji,Hei" of the sub-project of "Remote sensing survey of basic geology in coastal defense area of China",this paper attempts to evaluate the engineering geological environment in the lower reaches of tumen river as the research area,and achieves relatively ideal results.Through Delphi method and cluster analysis,this paper screen out the evaluation factors of the system,which include 6 first-class indexes,such as geological conditions,geomorphological conditions,engineering conditions,hydrological conditions,infrastructure conditions,surface landscape conditions,and 12second-class evaluation indexes,such as natural building materials,fracture structures,macroscopic geomorphology,visual analysis,soil and water conservation,engineering rock and soil mass,geological disasters,river width,groundwater enrichment,infrastructure,landscape types,and vegetation coverage.Combined with the improved gray evaluation method based on analytic hierarchy process(AHP),this paper constructs the evaluation model of engineering geological environment in the study area and has achieved the following main results:(1)With the help of GF-1,ZY-3,Landsat8 satellite image data and ASTER GDEM elevation data,this paper uses remote sensing and geographic information system technology as the main means and the field reconnaissance,sample testing,program design and expert consultation as auxiliary methods to establish corresponding remote sensing information extraction models or image interpretation marks respectively,thus completing the information extraction of secondary index elements and the production of index thematic graphics.In addition,taking C# and Arcengine as development tools,this paper also extracts the index factors of river width,with realizing the automatic extraction and segmented representation of river width of boundary river.(2)Through combing the evaluation system based on analytic hierarchy process(AHP),this paper not only establishes the index comparison judgment matrix and carries out consistency test,but also gives each index a reasonable weight.Moreover,in the comprehensive analysis of raster graphics,this paper puts forward a two-class index scoring model and formulates the corresponding quantitative grading standards of evaluation factors,thus determining four evaluation gray categories including "suitable,relatively suitable,poor suitable,and unsuitable" and constructing the definite weighted functions in combination with actual conditions.(3)Through model calculation,the gray evaluation value of engineering geological environment in the study area is 3.0555,and the overall evaluation result is that the study area is relatively suitable for engineering construction.At the same time,in accordance with the evaluation result graphics,it can be seen that the areas with suitable,relatively suitable,poor suitable and unsuitable gray evaluation are 41.9%,38.8%,14.7% and 4.6% respectively.Among them,the areas with higher evaluation values are distributed continuously and have a large proportion,and mainly distributed in mud-gravel valley slope terraces,soil lacustrine plain,gentle hills and shallow hills,with great potential for engineering development.And the evaluation results are basically consistent with the qualitative understanding and have high reliability.