Study On The Application Of Urban Rail Transit Planning Environmental Impact Assessment Index System

Urban rail transit has entered a period of rapid development in China from the 21st Century. It plays an important role in cities, because it can alleviate traffic problems, activate urban economy, stimulate urban development and improve image of cities. However, rail traffic also brings the negative impact to urban environment and social environment during its construction and operation period. Urban rail transit planning EIA can involve in the early stages of decision-making. It makes planning recommendations on the planning program from the perspective of environmental protection and guides the direction of the development of the planning, to protect the environment from the source, and to promote construction of urban rail transit developing coordinately and sustainably with the environment.The paper first establishes an urban rail transit planning EIA index system, then refers major steps of urban rail transit line network planning comprehensive evaluation,finally doing urban rail transit planning EIA based on the index system, aimed at evaluating the network planning from the view of environmental point, and providing a basis for selection decision-making of line network planning program.The main research contents and results of the paper are as follows:(1)Based on the environmental impact identification of rail transit, a set of suitable basic index system was established for urban rail transit planning EIA. And the meaning of the indexes was introduced, the means of acquiring the index value was explained.(2) The method of FAHP (Fuzzy Analytic Hierarchy Process) based on fuzzy consistent matrix to determine index weight was proposed.(3)In response to the characters of the evaluation index system, and the fuzzy feature of urban rail transport system, comprehensive environmental evaluation method based on gray correlation degree method was proposed.(4)At last, the methods were proved in Xi'an Urban Rail Transit network planning EIA. Evaluation index system was constructed based on surveying the state of the planning district environment, analysing planning programs and environmental impact identification. Then the index weights were calculated by using the method of FAHP, and the index values of pre-programs were assigned. Finally, selection was made by using the method of gray correlation degree, and the optimal environment program was determined.