Optimal route finding of water transmission lines by comparing different MCDM methods and the least-cost path algorithm in a raster (Case study: from Ardak to Mashhad)

Routing is one of the most sensitive parts of the design of power transmission lines. Any mistake in choosing a route can lead to high costs or costs for regional water companies at runtime or line operation. In this research, to solve the problem of determining the optimal route of water pipelines using spatial analysis, a multi-criteria decision making and raster-based shortest path algorithm were used from Ardak to Mashhad. For this purpose, firstly, the effective parameters in determining the route, including slope, geology, land use, residential areas, Waterways, roads, faults, and protected areas were determined and after weighting processes in AHP, TOPSIS and Fuzzy Logic methods, overlaid in the form of information layers in the GIS environment in order to generate cost mapping. Then, using the lowest cost algorithm in raster, the optimal path was determined. Finally, a comparison was made between the traditional way provided by the consultant and the proposed route with the lowest cost algorithm. The paths obtained from the lowest cost algorithm based on AND, GAMA, AHP, and TOPSIS were equal to 44.798, 46.755, 45.731, and 45.531 km, respectively. On the advised paths of the consultant, Route 1 has a length of 72.306, a suggested track 2 has a length of 63.108 and the third one was 48.690. Finally, the TOPSIS route model was selected as the best route due to the consideration of the forbidden areas.