Hydrological Effect Evaluation Of Railway Vegetation Slope Protection In Cold And Arid Regions Of Northwest China

With the economic development of Northwest China,railway construction in Northwest China is becoming more and more perfect.While bringing economic and social benefits,both railway projects have also caused ecological environment damage and increased security risks.Because it is easy to be affected by the environment and geological structure in Northwest China,the slope belongs to the part of railway engineering structure which has been damaged more seriously,the vegetation degradation,soil erosion phenomenon is widely distributed,and the geological disasters such as landslide and debris flow occur frequently.Vegetation slope protection is an effective measure to prevent the occurrence of geological hazards and restore the ecological environment of railway slope,in which hydrological effect is an important way for it to play its role and evaluate its functional status.It is an effective means to strengthen the management of vegetation slope protection and to promote the analysis of geological hazards,and it is also the basic work to improve the effectiveness of vegetation slope protection.Based on the in-depth study on the mechanism of vegetation slope protection,this paper analyzes the main influencing factors of plant slope protection from vegetation and soil,and improves the existing index system in combination with the climatic environment,railway geology and plant profile of northwest cold and drought area,and constructs an evaluation index system of hydrological effect of railway plant slope protection in northwest cold and drought area composed of 5 primary indexes and 16 secondary indexes.On the basis of using traditional analytic hierarchy process(AHP)system to decompose hydrologic effect target,the IGAHP method is used to quantify the difference between experts,to determine the subjective weight of index,and to determine the subjective weight of index by CRITIC model.5333,maximum 0.7.The remaining subjective weights are 0.5.According to this,the subjective and objective weights are combined according to their corresponding combination coefficients,and the results of the index subjective and objective combination weighting are obtained.Based on the theory of combined weight and element extension,the evaluation model of hydrological effect grade of slope protection is constructed,and the incompatibility contradiction between the establishment of correlation degree function and the introduction of correlation degree function to transform the index in the evaluation process is constructed.The problem of no solution in the calculation of index correlation degree is solved on thebasis of the reasonable calculation of guaranteed distance through the normalized processing of classical domain.Finally,three slope protection sections in Tianshui-Qin'an section of Baolan high-speed railway are selected for empirical analysis.The results show that the evaluation results of hydrological effect grade are in order of grade ?,grade ? and grade ?,good and general hydrological effect of slope protection.