High quality treatment and application of information is necessary for effective and economic decision making, This paper will inform about analysis and application of GIS for rail transport using PC ARC/INFO, which is applicable to any urban rail network in the Czech Republic. Graphical data files record the details of the rail network facilities enabling easier maintenance.
Today large amounts of information have to be processed. There are demands for quality information and a higher quantity of system storage. Commercial businesses and industry require highly efficient information technology systems.
Previously there were many conditions which are still valid within rail transport. Therefore it is necessary to keep certain register systems of rail links, especially from the point of view of the placement of the rail network basic facilities. These will help to increase transport efficiency and fluidity and decrease fault liability and the number of accidents. It will also reduce maintenance, services and designing expenses.
The high number of specifications concerning e.g. objects placed in existing areas, towns, institutions and/or authorities will be maintained. It is the administrator of distribution networks such as telecommunication, heating, electricity etc. who need the GIS system. With the computer's performance increased, especially by a RISC architecture package, step by step environment monitoring, its modelling and/or conceptual planning were the "big" GIS systems to put across.
From an expert point of view, one can say the GIS computer system is used for data storage, maintenance, editing, displaying and plotting data concerning real objects placed in the space which can be shown (described) in an Earth surface co-ordinate system.
The use of GIS is extremely advantageous for urban networks such as a tram network, railway network, subways, road network, pipelines etc.
It is possible in GIS to display a tram network within one map, to create data tables connected directly to a digitised map at a proper scale. This will enable a complex network to be easily, economically maintained or repaired and partially or completely reconstructed. Such a system can find the necessary data quickly and effectively and does not require a large amount of valuable storage space. We can create a unified GIS system which caters for the various requirements of different companies such as road maintenance companies, gas companies, electricity distribution companies, water treatment, sewage systems etc. It is possible with GIS to work with a computer net. All interested companies may be connected within the computer net and possible repair and reconstruction will be planned together. This would help to decrease costs and increase people's standard of living in the area during the repairs. Repairs should take less time; only one excavation will be needed so there will be less road repair works.
To achieve greater expansion companies should invest in effective hardware and software systems which would benefit them (mostly state subsided companies). The initial cost is too high for them. There is need to think ahead and it is only question of time before such a system will prove to be an economic asset for the future.
The tram line network consists of independent and related features (objects). We are interested in the overall economic technical information about the network e.g. directions, proportion, high level altitude, rail support, etc. The objects differ by type and are assigned different structural data tables for each of the object drawings (digital maps) which must be presented separately. Drawings are divided into separate layers which can be displayed separately and/or together. Particular layers can be activated directly by entering the layer number which is faster, or by entering layer name. Each layer and its number has an appropriate colour for better and easier orientation within the layers.
Each object may not be "monolithic" for the whole line (the use of one technology type is not assumed) so it is necessary to divide the whole line into segments corresponding to its technology types at the change-points (where the technology types change) - for each separate layer.
The structure of the information system is shown in Table 1. The table description is based on the structural distribution of particular layers into groups. It is possible to redistribute the particular layers into groups with the respect to topical distribution, and such a change can be done quickly. Objects can be related to single parts of the map: line of a route, line of other objects belonging to a route (there is no need to measure or survey, if it is a part of cadastral map). A new layer can easily be created which may be of interest for further processing. It is not recommended to change the structure during the time when data are being processed.
|DISTRIBUTON OF LAYERS|
|PROJECT||LAYER||NAME||CODE||NUMBER OF LAYERS||CLASS OF OBJECT||TYPE OF OBJECT|
|tram network||tram track||space||HA||1||horizontal alignment||linear|
|top of tram||R||3||rail||linear|
|TOT||8||tram object top of rail||linear sign|
|STK||9||special tram construction||linear|
|bottom of tram||BL||10||bottom layer||linear|
|tram object||TS||12||tram stop||sign|
|next tram objects||O||13||object||linear sign|
The created object contains the graphic data (map) as well as other files which will be used by the information system. These are database tables, graphic files (cross sections, side views, layouts etc.), raster graphics files (scanned drawings and pictures) and text files (appropriate information about the object).
During the operation of information system there may be changes in the lines. Hereupon, it is necessary to make some corrections and update the system. Updating can be run at a number of "levels".
a) In the case the changes held in the original break points, only data in the database will be changed.
b) Another possibility is that the whole line changes. In this case the old line is deleted and a new one is plotted. New objects will be created with graphical components, and the new data will be put into table structures.
c) When changes to the line will not be held in the original break points but in different points, then it is necessary to change the graphic distribution of the line.
During the time when changes are made (as well as during the time
the information system is in use) it is only necessary to use
the layer which belongs to the changed object. It is beneficial
to leave the other layers switched off. This procedure is better
and makes it easier to find the correct object.
Information can be displayed in two ways:
a) Direct pointing to the object whose information you require.
b) Searching using SQL query such as "SELECT + FROM + where from + WHERE + logic expression". Dialogue window Object/Query will be used. Dialogue window offers adjustment of display output e.g. location, highlighting and others.
The whole information system must be created as an open system, because during its life other demands will occur which were not taken into account in the base analysis and preparation of original functional GIS version.
All GIS components must be able to work with standard formats, both text and graphic. There must be full data compatibility of the different computer programmes used within the newly built GIS.
Acquiring a quality map base may be a relatively costly but necessary expense. However, it may take years to build the system, so it is very important to utilise existing map bases.
A practical approach based on effective data design for text and numerical data is necessary (from the point of view sorting and searching for data).
One implication of inserting the GIS into any organisation and/or company, which can not be underestimated, is the structural organisation that will occur. It means the whole organisation and/or company will be lead by professionals.
As use of the GIS within the state/municipality organisation is needed more and more, more qualified (preferably young) people will be needed as well. It must be noted that it will be necessary to teach about the system in schools. Clearly, not only selected experts would acquire this knowledge, but regular students and those of high technical schools and universities who use maps in the course of their work (e.g. civil engineer, geologist, ecologist, pipeline maintenance etc.) would share the knowledge as well.
Building the GIS had its rules. It had to be a "made to measure system" for each customer because each area of use has its own specifications which were not able to share one general environment.
The system was created by Department of Railway Structures and Constructions. Many diploma students and teachers were involved in the design stage of a pilot project. It is possible to use the system for municipal networks immediately.
Dept of Railway Constructions and Structures
Faculty of Civil Engineering
Technical University of Brno
Telephone: 42 05 7261323
Fax: 42 05 745147