عنوان مقاله [English]
Considering theproper and comprehensive criteria at the route locating stage can play a major role in reducing economiccosts, increasing safety and accessibility to roads and preserving the environment. For this purpose,several parameters such as Ground Elevation Model, land cover, demographic and tourism information, how sunny the roads are during cold seasons, distribution of rivers and fault lines were considered for optimal routing of the Ilam-Homeil road in this research. In order to determine the inter-layer cost, a knowledge-based approach was proposed based on which, a cost function was considered for each of the layers in accordance with its characteristics and its way of influence on providing the goal. The main advantage of this approach isthat the cost variations are not merely linear for the existing data intervals in each one of the layers, and the characteristics of corresponding layer areincluded in the definition of relevant cost function. Next, the pair-wise comparison and Analytical Hierarchy Process (AHP) wereused, taking advantage of the experts’ opinions, for inter-layer weighting. Accordingly, the shortest routewas implemented throughcombining layers and the method of overlapping index by providing the lowest cost with 3 variables or different variants. In the first variant, the common methods (linearly) were used for inter-layer weighting. In the second variant, the only criterion used for determining the route was the slope criterion. The proposed method of knowledge-based weighting was applied in the third variant, taking into account all the criteria. Based on the results, less attention has been paid to factors such as distance from the fault lines and the rivers, access to population centers and tourist area in determining the constructed route, and the main criterion in routing has been the topography of the region alone. Also, the length of the route in all of the three variants is less than the length of the constructed route. In general, the route resulted from the application of knowledge-based weighting has a better statusin providing different criteria than the constructed route, as well as the two other variants.