Identified By Remote Sensing Of Turfy Soil And The Environmental Effects Affected By Engineering

Turfy soil is a kind of special soil with high content of humus piled up with incomplete decomposed plants.It forms a class with unique properties which is different from other soils,including high organic matter,high moisture,high void ratio,high-compression,and low decomposition degree.Because of the special external environment,it will bring many problems in geotechnical engineering design at the region of turfy soil.With the rapid development of highway,projects in turfy soil area become inevitable,dealing with the foundation in turfy soil swamp is needed,which will result in the degradation and disappear of turfy soil basin.So the research of influence of road engineering to turfy soil basin,can provide necessary theoretical basis for the projects in the turfy soil area,moreover,it is conducive to the protection to the turfy soil swamp,showing both economic and ecological environment benefits.Because the distribution of turfy soil basin is broad and scattered,doing research by the field investigation,on the one hand,will takes a long time with a lot of researchers,while the results would not be comprehensive;on the other hand,taking into consideration of the genetic mechanism and forming environment of turfy soil--for the turfy soil formed in the swamp basin,it can hardly be field investigated.Combined with remote sensing results,with the field experience of turfy soil engineering,modeling the recognize patterns from field investigation points to unknown areas,so as to analyze the distribution and evolution of the turfy soil.And combined with the typical turfy soil basin with road engineering,analyzing the influence of road engineering to turfy soil swaps,is an effective mode in view of the turfy soil basin with special formation and shows both economic and ecological benefits.Based on the above reasons,in this manuscript,based on the national natural science fund projects of ‘environmental effect of road engineering to turfy soil swamp in season frozen zone',‘Study on the structural property and constitutive relations for marsh turfy of seasonally frozen region',‘mechanism of frost heave of turfy soil in season frozen zone',with the field experience,combining with the 3D visual function of the Google Earth,analyze the remote sensing properties of turfy soil;field investigation of turfy soil was designed,and the distribution and remote sensing characteristics of turfy soil were analyzed according to the results of field investigation,and nonlinear classification method such as support vector machine,neural network were applied to analyze the identification effect of turfy soil.Combining with the fuzzy mathematics,according to the formation of turfy soil,a fuzzy recognition model for turfy soil was established assisted with MATLAB,and a recognition mode interface was finally attached for automatic identification of turfy soil,and field results was taken to verify it.Two special turfy soil basin was taken for instance for automatic identification,and the results of fuzzy membership degree,combined with the corresponding results of geophysical prospecting and drilling,was to analyze the evolution regularity of turfy soil naturally and with the influence of the human engineering respectively.Three representative turfy soil basins were selected,based on field investigation,sampling,testing and indoor tests,physical and chemical parameters of turfy soil influenced by road engineering was decided,and remote sensing spectral data and elevation data were obtained for correlation analysis with test results for parameter inversion.Combined with the accuracy of the test results and the spatial continuity of remote sensing data,the influence of road engineering to turfy soil basin was analyzed and finally the probability model was established,and combined with the experimental data and remote sensing data,evaluation methods of effect of route engineering to turfy soil was established by the secondary analytic hierarchy process.Based on Landsat4-5 remote sensing image,the distributions of turfy soil in eastern Jilin Province was recognized and predicted,and the evolution of turfy soil basin was analyzed by the calendar year remote sensing image.The mechanism of turfy soil was analyzed by CA-Markov model,and the evolution trend of the turfy soil basin was also predicted.In combination with Google Earth,the geographic information data integration system of turfy soil was established,and the survey data,test data and site photo of turfy soil was set up as a database,with main conclusion as follow:1.With field investigation and classification of turfy soil,we found that:(1)Based on field investigation,the forming mechanism and remote sensing properties was analyzed,and we found that the distribution and evolution of the turfy soil are erratically.The water and vegetation can be quantitative descried by remote sensing so as to recognize the distribution of turfy soil.(2)By the different methods to identify the turfy soil,we found that although the distribution of turfy soil can be recognized by these methods,but for same special area such as farmland degraded by turfy soil,the results are still not precise enough,a special recognition model combining with the genesis mechanism of turfy soil is required.2.With the establishment of turfy soil identification model based on fuzzy mathematics,it is concluded that:(1)Qualitative identification and threshold extraction of turfy soil,combined with normal fitting,cellular matrix and fuzzy evaluation,make the effectively identify of turfy soil possible,Recognition results of turfy soil through on-site validation,can be used as a new known data,so as to improve the accuracy of recognize model.(2)Fuzzy evaluation model,based on the genetic mechanism and evolution process of turfy soil,described the ownership of every pixel and evolution of turfy soil by fuzzy membership degree,which contacted the model parameters with the physical meaning of turfy soil.(3)On-site results were obtained to validate the precision of the recognize model,and drilling and geophysical exploration data also verify the accuracy of the membership degree results;Fuzzy membership degree was used to analyze the evolution process of turfy soil both naturally and influenced by human engineering,which show great environmental ecological benefit to protecting of turfy soil swap,and the same for swamp wetland protection.3.Indoor experimental results show that:(1)The test results were obtained to analyze the distribution regular of turfy soil by the degree of decomposition,the comprehensive evaluation of water and soil and the thermal performance,comparing with different areas,different depths and different distances to the road engineering in three turfy soil basins of Huang Songdian,Jiangyuan and Jingyu,revealing the distribution regular and environmental effects of turfy soil by road engineering.(2)The experimental results show that there is significant correlation between the thermal effect,elevation data and physical chemical parameters of turfy soil.This means that,physical and chemical parameters of each pixel in turfy soil basin,can be calculated by test parameters and the remote sensing data,which show both the accuracy of the test results and the space continuity of remote sensing data,moreover,it overcome the chanciness of profile sampling.4.Comprehensive evaluation model of turfy soil combined with probability model and analytic hierarchy process(AHP)showed that:(1)The probability model of turfy soil is built in the polar coordinate.The pixel point coordinates(x,y)of turfy soil,as well as the distance to the road engineering,was replaced by two parameters of r and ?,which simplifies the model parameters,moreover,it made the physical meaning of the parameters independence.(2)On the basis of probability model and analytic hierarchy process(AHP),every pixel in turfy soil basin was evaluated,and the three-dimensional image was to show the evaluation results,while the polar coordinates,specially to show the environmental effects influenced by road engineering.5.By the space-time evolution of turfy soil,we found that:(1)With Landsat 4-5 as remote sensing date sources,after image correction,splicing and tailoring,support vector machine(SVM)was adopted to recognize the distribution of turfy soil in the eastern Jilin Province.Special turfy soil basin was selected,combining with remote sensing images of past years,so as to analyze the effect of road engineering.(2)With Google Earth as the platform,the field investigation data,the experimental data and remote sensing identification results of turfy soil,respectively,were established as an information integration system.