Oil pipeline route optimization using multi-criteria analysis in GIS

Introduction:
According to distribution requirements and the broad distance between production and consumption centres in Iran, linear infrastructure development plays an important role and should be considered as a vital necessity. Routing problems include many factors which are often incompatible with each other and incompatibility amongst parameters causes significant delays in the process of routing. Hence, it is of interest that use of the new utilities in Geographic Information Systems (GIS) to optimize the routing process can resolve the difficulties faced in decision-making steps.
Material and methods:
This study aims at optimizing oil pipeline routes from wells drilled to the refinery by using different scenarios and to consider is ORness and ANDness. In the beginning preparation stage all necessary spatial data Like, Geology, land cover, slope, Dem, Fault, Main, River, stream which are required to find the optimal route for establishment of oil transmission line have been collected than Standardization and Preparation by  using reducing and Increasing linear weighting function. AHP process has been hired in order to find spatial weight of each parameter’s effectiveness in terms of cost of establishment and oil line interaction with its surrounding environment. Ordered weighted average (OWA) method has been applied to integrate spatial data and achieve the result, cost layer.  Dijkstra's algorithm has then been used to find the optimal route between the location of wells and refineries.
Results and discussion:
The results show that with increase in the value of α, the amount of cost, average slope and height of the oil transit route increase. In scenarios with, higher values are given to high-value pixels. While higher order weights are assigned to values with a lower numerical value in the same position. Therefore, the length of the route from the All (AND) scenario to the At least one (OR) scenario decreases. Because the Dijkstra's algorithm is a single-objective algorithm and aims at extracting the path with the least cost. Because at every move, Choose a pixel with the lowest Accumulative cost as the direction of motion and do not pay attention to the length of the route.
Conclusion
:  By comparing the existing route and the paths obtained from the Dijkstra's algorithm in different scenarios based on the factors of length, cost, mean slope and height of the route extracted In Almost All, Most, and Half (WLC) scenarios, are better than the other options in terms of techno-economic and environmental conditions in study area. Other scenarios have produced better results than some of the existing ones in some of the factors. Providing Various Results, With ORness and tradeoff this method has great flexibility in estimating the needs and priority of decision makers in the field of petroleum industry to design optimal transmission lines.