AHP And Fuzzy Comprehensive Methods In Railway Landscape Evaluation

Railways remain the most energy efficient mode of transport in the world, because it plays a major role in the movement of bulk commodities for long distances. With the development of economy, the demand for railway sector is increasing. This led to the construction of many railway tracks and extension of railway network in many countries. Railway transportation is more efficient in land use and it is superior when it comes to environmental impact and safety but it still has major impact on the landscape. Researchers have realized that it has a significant impact on landscape. Evaluation is necessary to identify and prevent negative impacts on the landscape. The railway landscape evaluation is an edge science that crosses over the natural science, social science and new technology. The primary purpose of the evaluation is to identify the variations in quality that exist across the landscape of a region so that; appropriate strategies for landscape conservation, management and enhancement can be defined. The determination of the first level of a railway is issues of the evaluation, but it is not an easy task because of complexity of the system to be resolve. Railway landscapes have a variety of elements which have a dynamic structure. Three dimensional spaces and changing constantly with time are among of the elements. Protection of these dynamic structures is very important for the future. Landscape researchers, landscape architects and engineers have a great responsibility on the landscape because sustainable development needs to depend on study and analysis before and after any project is taken.Many countries such as United States, Japan, Germany, England, France, etc., had carry out the research on the highway landscape and obtained encouraging results. Early, researchers start to study the highway landscape; therefore the evaluation of railway landscape began years later. The railway landscape evaluation is a scientific and technical solution used by many disciplines, for helping engineers to make a prediction on the landscape. This technique is based on prediction and evaluation of particular area of the landscape. Serious analysis of each factor of the landscape will determine its structure in relation with the ecology. Therefore, railway construction includes landscape evaluation, protection of landscape resources, and improvement of the effectiveness of environmental impact assessment. With the growth of population and new development projects, many railway facilities have been constructed across the landscape. This lead to land use management and ecological protection as species protection, water body protection, vegetation protection, include the correlation between each factors of the landscape. The visual impact of a project on the landscape need to be predicted for understand changes along the landscape, in the same time the aesthetic design based on public preference will be analyze.This paper has adopted Delphi method for investigation. Delphi method is based on expert subjective judgment and evaluation on an object. This method has been developed through expert conference, with the purpose to collect different opinions. Choosing the ideal experts is one of the most important works of the Delphi method application. Choosing an expert depend on the type of problem to be solved. In choosing experts, we must choose both those proficient in the subject areas and expert in related disciplines. We should also pay attention to choose the edge discipline experts such as sociology. We should also consider experts subordinate departments and units of universality. The numbers of expert depend on the scope and the problem to be solved. After the return of expert opinion, check the degree of concentration and dispersion to determine whether the investigations need one more rounds. Survey results need a statistical processing. Studies showed that the probability distribution of expert opinion generally close to normal distribution. This is an important theoretical basis for expert advice on statistical processing. The index weight values should take all experts reports provided by the average of the final round results.There are two kinds of representative railway landscape evaluation methods. The first kind focuses on the individual or group of landscape quality and proceed to a subjective non-quantitative evaluation, it's include also a detailed description methods, public preference method, etc...; the other method is based on the physical characteristics of the landscape and rationally analyzes the research. Moreover, it obtains objective quantitative evaluation using quantified synthesis, principal component analysis, gray correlation analysis method and comprehensive evaluation method. These detailed descriptive methods include ecological patterns and aesthetics shape patterns. These two methods are widely use for objective research on railway landscape. Public preference methods such as psychological pattern and phenomena mode often use survey questionnaire and other methods to test public opinion on the subjective views of the public. Quantitative synthesis subjective method and objective rational method are combined with psychological pattern to constitute the alternative mode. This thesis shows the different steps of railway landscape evaluation process and landscape theories. The thesis is based on full investigation methods of the railway landscape and studies the landscape evaluation index system based on existing data. The study is based on quantitative and qualitative method, it analyze the impacts on ecosystem and determine the index system using Brain storm method, Delphi method and Seminar method. With a complete establish of index system including the three base of the system namely the visual environment quantity of landscape, the ecosystem environment quantity of landscape, landscape resources value and 57 indices as subordinate to base. The thesis use AHP method to make sure each index is rank according to their importance after calculation the consistency checked as verification. The main step include of AHP are:Fix the goal; likely index system of the evaluation; build up layers; determine the judgment matrix; arrange layers and check the consistency; arrange top layers and check consistency.According to china and international related fields choose the faint-synthesis evaluation method to evaluate the railway landscape. The index systems reflect the structure of the landscape and the problem to solve. The study area will cover an entire region (cities or district) to determine the representative index and it importance. The thesis chooses representative railway landscape as an example of the research. The method used in this paper is a multi-level fuzzy comprehensive method combined with AHP which is illustrated in the experimental analyze. This method is more accurate than the traditional fuzzy comprehensive evaluation method. The main steps of multi-level fuzzy evaluation method are:the index system structure determination, the calculation of corresponding weights, evaluation matrix. The results show that the railway evaluation index system can reflect the different element of the landscape, and their current condition is determined after weighted them. After evaluation of a landscape attention will be pay on weak area for more research to get better solution for to mitigate and repair damages. The evaluation of railway landscape helps to solve problems in different stage of projects; as in project design phase, in operation phase for maintenance, and for landscape qualities improvement.The thesis provides the foundation of the railway landscape evaluation; the theories of the index system and the method of the evaluation provide the beneficial reference for the highway landscape research.