The Research And Implementation Of Urban Bus Emission Simulation And Analysis System Based On GIS In NANJING

Faced with an increasingly serious traffic pollution problems, the state promotes priority development of public transport, the development of public transportation has become one of effective solutions. Under the background of promoting energy conservation and emissions reduction and the rapid development of intelligent transportation, this paper does a research on diesel buses' emission in Nanjing, implementing the combination of micro emission model(V-VSP model) of buses in Nanjing that based on PEMS(Portable Emission Measurement System) data and GIS(geographic information system) technology, completing the development of urban bus emission simulation and analysis system and implementing assisted analysis tool of urban bus emission.Firstly, introducing the geographic information system technology and analyzing the current GIS development mode. The development of urban bus emission simulation and analysis system uses mainstream component GIS technology, the urban bus emission model uses the V-VSP micro emission model, the system interface is built by DevExpress controls which is used widely.Secondly, completing the overall design of urban bus emission simulation and analysis system according to soft engineering theory which includes system design objectives and principles?system requirements analysis and development process?database design and system function module design. System design objectives and principles establishes the goals which is expected and design principles that followed; system requirements analysis analyzes in data requirements and function requirements according to users needs and system development process determines the technology roadmap of system development; database design is the effective organization of data which mainly includes spatial database design and attribute database design according to type of data; system function module design is based on the function requirements analysis which makes the system's functions to be organized effectively. The overall design is a conceptual design which provides a theoretical framework for system development.Then, researching on the algorithms of urban bus emission simulation and analysis system based on system function module design which include bus GPS data processing algorithm?bus line matching algorithm?point emission calculation algorithm?line emission calculation algorithm?emission hotspot analysis algorithm and area emission simulation algorithm. These algorithms mainly solve the problems which includes bus GPS data drift? the displaying of bus line data which is matched with bus track?the emission calculation of various exhausts of line nodes?the emission calculation of various exhausts of whole or part line?the spatial distribution of various exhausts. The algorithms that proposed have achieved the desired effect which indicates that they are feasible.Finally, implementing the detailed design and programming of urban bus emission simulation and analysis system based on overall design and algorithm researching, the system is tested on the basis of part lines data and buses GPS data in Nanjing which achieves the desired effect and can be used to simulate and analyze bus emission.