DEVELOPING A GEOSPATIAL MODEL FOR POWER TRANSMISSION LINE ROUTING IN TURKEY

SUMMARY Power Transmission Line (PTL) construction is one of the most complex engineering projects. Routing a transmission line is much more difficult than routing any other public infrastructure. Especially in developing countries like Turkey, the present PTL routing system used is time consuming and does not produce satisfactory results because PTL routing is done by manual methods using 1/25.000 standard topographic maps or smaller scale paper maps. Current route determination methods are considerably insufficient in transmitting the power to long distances. The optimum route for PTL in the majority of cases is not the shortest path between the start and end points. For the determination of the optimum one, many factors which affect the route should be considered all together. Some of these factors are (i) technical factors such as slope, landslide, earthquake/fault, road/railway/pipeline crossing, lightning strike, wind, snowfall, and thunderstorm; (ii) environmental factors such as national parks, archaeological areas, water resources, river crossing, wildlife, and forests; (iii) socioeconomic factors such as agricultural areas, residential areas, cultural assets, temples, shrines, recreation areas, tourism, right of way, and relocation. Each of these factors basically corresponds to a spatial data set. Therefore, optimum PTL routing is a spatial problem. GIS is currently one of the most effective tools for resolving such complicated spatial problems. In GIS, raster data models which is used for storage and visualisation of spatial data sets provides important advantages especially in such projects which is to be constructed for long distances. This article presents a raster-based GIS model developed for PTL routing and lists the advantages of the model in a PTL implementation. Routes defined with network analysis techniques over raster-based GIS models minimize economic, environmental, and time costs, depending on the quality of data used.