These instructions give you guidelines for preparing determination of optimum path by considering technical and engineering, environment and cost management visions. In this point of view from Taleghan’s dam to Hashtgerd New City case study, we need to distinguish and apply the essential parameters such as topographic and morphologic conditions, environmental issues by consideration on sustainable development, population distribution patterns, roads and etc. by using base map and extraction of expected points geometrical location from Google Earth, position land surveying done. Then the mentioned co-parameters data layer loaded in GIS environment and after allocation the special coefficient and value for weighting parameter s and combine them based on MCE method and the cost map made based on AHP method which Lead to determination of optimum path by using LCPA method. Paths include of ABFA path and two evaluated optimum path compared and indicated that two optimum paths overlapped mostly. Cost comparison between optimum path and ABFA path imply 14% decrease in expenditure Which the main extra expense of ABFA path due to more intersection with rivers, roads and necessity construct of structures to keep water natural regimes, passing unauthorized areas and personal parcels need to pay, path finding only by personal experience underestimating academic science, data analyzing software’s which Cause to increasing the length of water supply pipeline.
Initial design of path and phase zero study, is one of the most important steps in construction of the pipelines in before construction starting from different aspects investigated and safest and most economical location of path construction recognized [
Over two decades paid attention to GIS software ability in path designing such as road, rail way, oil and gas and water transition pipelines telecomunation cables and so on.
In the case of finding optimum path for pipeline by using GIS, several multiple project done in the world wide but in Iran country lack of GIS ability knowledge cause to ignoring GIS in the project’s design phase.
1) Naghibi on 2002 in Tehran university investigate the part of oil and gas transition pipelines of Ahvaz-Maroon axis by using GIS; At the end he concludes that constructed path 29% more expensive than designed path by software which technical and bio-economical impacts considered [
2) Shoubiri et al., on 2015 performed optimum path finding of water transition pipeline by using DEM (Digital Elevation Model) and GIs tools. In this research by DEM obtained from satellite and GIS used for reaching optimum path. Base of this purpose major criteria listed and valued each criterion by expert and all the layers matched corresponds to their values and after all the optimum path revealed. The proposed path by the GIS possess benefits such as higher technical value and shorter pipelines length rather than built pipeline path [
3) Yildrirm and tomuralioglu on 2011 comparing the path finding method for oil and gas pipelines traditional procedure. In this research prove that the path which designed by using GIS 14% cheaper than the path with traditional procedure and even though GIS software is more user friend than other softwares. Also GIS giving us both conceptual model and real model correspond to topographic terrain. By using this system most of main aspects such as effective parameters on pipelines path finding determined. Furthermore, for assigning value of each parameters used AHP (Analytical Hierarchy process) method [
4) Balogoun et al., on 2012 perform research with title of choosing optimum path of oil and gas pipelines using by GIS. In this research the value of variables depends on amount of importance these variables for society. They evaluate valued variables based on the amount of vulnerability for ecological habitat and finally the proposed method concludes to less environmental hazard [
The result come from mentioned researches validated the GIS ability on automatically path determination and also he experiential results imply that final output of perform to optimal output. Noticeable point, detecting the effective parameters correspond to purpose of project, the area conditions and also relative values for them which better to consider experts’ suggestion.
The final purpose of this research, the participation of effective parameters by using GIS, LCPA (Least Cost Path Algorithm) and MCE (Multi-Criteria Evaluation) method on determination of optimum path and also compare optimum path with constructed path by the Alborz province water and wastewater company point of view technical and engineering, cost management and bio-ecological.
1) The first group believe to economic views that deduction of time, cost and path are very important for them.
2) Another group believe to environmental views that they emphasize to deduction of environmental hazards (a) Environment factors b) Ecological factors c) Human factors).
3) Consolidated views that includes two preceding views is new theory and views on the world that it is used in this investigation and according to this views to some theories related to the path finding in this investigation will be discussed. The theories include of:
In modern age growth of cities will likewise increase the demand for water pipelines. Pipelines are by far the most economical, practical and safe option of fluid transport. An important problem in pipeline is the path finding assignment [
Traditional method of optimum path in pipelines are mainly based on expensive and protected methods. These methods are not precise and the role of all effective parameters in pipeline path finding cannot be easily considered. Most technical, economical and environmental concerns are not observed in designed path. Meanwhile GIS, remote sensing and intelligent methods are efficient tools for decision making and consultation for experts in pipeline design ( [
The GIS, as a new technique for collection and analysis pf spatial data, together with genetic algorithm as one of the most important evolutionary algorithms with features like flexibility, robustness and consistency in solving the complicated problems have important functions. So, combination of information from satellite images, object-oriented programming, available GIS techniques and genetic algorithm can lead to more accurate results in shorter time [
Thus, selecting a suitable path to avoid existing obstacles not only reduces the risk of damaging existing utilities, but also minimizes the cost and duration required for construction. The GIS helps planners identify the spatial relationships between different data layers. In addition, GIS not only stores the spatial features and attributes, but can also be used as an analysis tool [
A GIS usually provides a number of tools for the analysis of spatial networks. It generally offers tools to find the shortest or minimum path [
Various investigations have been performed for using genetic algorithm in path finding problems optimization [
Careful planning of their path can save on cost, time and operating expenses, ensure longer operational life and help prevent environmental fallouts. So, it is clear that more efficient methods for path design are required ( [
The path finding technique used for calculating shortest path, cost reductions reported by the companies was typically between 10% and 20% [
Taleghan small town locate 100 kilometers northwest of Tehran and between grand valley the Alborz mountains and Hashtgerd New City from geographically in west Tehran province at an altitude of 1310 to 1610 meters above sea level. The study area is between latitudinal 36˚12' to longitudinal 50˚47' and latitudinal 50˚25' to longitudinal 50˚55' and latitudinal 35˚45' to longitudinal 36˚5' (
This research is type of applied-analytical that first understudied library and documents studies and dispose of expert’s sessions for doing work, theory framework and path features. Then by using observation and field in investigations, relate existing maps and receive data in softwares environment such as
ArcGIS and IDRISI Selva, with due to condition interpret them. Finally, by allocating values to model, necessary tests, evaluated and validated of results, optimum path determine. So, recommendations based on research obtaining for study subject will present (
1) Effective criteria in path finding water transition pipelines;
The multi-criteria evaluation to achieve a certain goal, you need to define measures or indicators which based on them achieve to certain goal. These measures and indicators call evaluation criteria [
2) Path finding by using the lowest cost path algorithm in ArcGIS:
Finding optimized path by using LCPA in ArcGIS depends on point of origin and destination, cost map and accumulative cost map. ArcGIS software to calculate the shortest path first by cost map, point of origin and cost distance tool, cost surface in order to calculate cost of moving from origin to destination acquires and accumulative value of each cell and after accumulative cost map production, the optimum path from point of origin determine.
Reference | Description | Information | Criteria |
---|---|---|---|
National mapping organization | Include of permanent and seasonal rivers in the region | Rivers map | Ecological criterias |
National mapping organization | Include of elevation data which have made from region topographic map | Digital elevation model map | |
National mapping organization | It have made from digital elevation model | Slope map | |
National mapping organization | Include of major and minor road | Road map | Socio-economical criterias |
National mapping organization | Represent residential spots | Urban and rural region | |
National mapping organization | Include of installation of welfare, centers (cultural-religious) and so on | Infrastructures map |
a) Process of determining the optimum path by using Analytical Hierarchy process include of [
i) Weighting factors: Weight and relative importance of each factors must be determined in relation to the intended target. Since role and importance of each criterion in determining path are not same and in other words, limit factors in determining path are not same and some of characteristics, act as key factors [
Factors | The effect percent of factors |
---|---|
Slope | 50 |
Land use | 30 |
Linear objects | 20 |
Reason given coefficient | Weight coefficient (1 - 10) | Object |
---|---|---|
Personal property+ environmental damages + garden destruction + cost of ownership | 9 | Garden |
Personal property + environmental damages + vineyard destruction + cost of ownership | 9 | Vineyard |
Personal property + environmental damages + bare land destruction + cost of ownership | 2 | Bare land |
Personal property + environmental damages + agriculture destruction + cost of ownership | 8 | Agriculture |
Reason given coefficient | Weight coefficient (1 - 10) | Object |
---|---|---|
The high costs and official problems in the municipality and urban planning+ high execute costs+ increasing risk of rapture due to heavy traffic vehicles (pressure external load)+ high cost of urban taxes+ traffic | 9 | First class road |
High cost of urban taxes+ traffic+ high pressure passage of vehicles | 8 | Second class road |
High cost of urban taxes+ traffic+ high pressure passage of vehicles | 7 | Third class road |
Urban taxes | 5 | Fourth class road |
Urban taxes | 4 | Fifth class road |
Bridge construction cost+ environment destruction+ consider river natural regime and ground water | 9 | River |
slope | Weight coefficient (1 - 10) | Reason given coefficient |
---|---|---|
0.000247 - 7.959794 | 4 | For supply pressure into the transition pipeline need to cost + because of low or zero slope and water low speed and could flow fluently possible to sediment into the pipe + sedimentation path and water low speed (drop water speed cause of friction) + necessity for pumping water + cost of constructing pumpage station (external cost of electricity supply and so on) |
7.959794 - 15.919342 | 3 | For supply pressure into the transition pipeline need to cost + erosion of pipe |
15.919342 - 23.878889 | 4 | For supply pressure into the transition pipeline need to cost + increase friction coefficient of pipe |
23.878889 - 31.838436 | 4 | For supply pressure into the transition pipeline need to cost + increase friction coefficient of pipe |
31.838436 - 39.797983 | 5 | Erosion of pipe |
39.797983 - 47.75753 | 6 | Erosion of pipe |
47.75753 - 55.717077 | 7 | Erosion of pipe |
55.717077 - 63.676624 | 8 | Erosion of pipe |
63.676624 - 71.696171 | 10 | Impossible |
71.696171 - 79.595718 | 10 | Impossible |
ii) Create cost surface or friction: Purpose of this stage, produced a data layer in interlace format raster all cells move and pass costs can be attributes and this layer is called cost surface or friction. Taken together, the opinions of experts and specialists Alborz province water and wastewater company, weighting coefficient of effective parameters in determining the optimum path, dataset valued and by using weighted data, cost map as shown in
iii) Create accumulative cost surface: To generate this level as seen in
iv) Integration of maps and producing the final map: One of important parts of the regional analysis, the combination of data and information to create maps, layers and new data which shown in
3) Path finding in network GIS
Path finding algorithm in raster model, similar to operating algorithm in the vector model. But direction modeling in raster network rather than vector network is not simply but possible. To find the path of least cost must be on a level with the accumulative costs, to move on the cost values must combine a variety of different cells that is a bit complicated [
Process of determining the optimum path in network GIS include of:
i) Create cost surface or friction: How formed these levels depends on criteria used in determining the path. Cell units of this level can cost, time, distance and so on. But the important problem, resistance of each cells determined by value allocated [
ii) Create accumulated cost surface: The accumulative cost of the function rather than the actual distance between two points is calculated, weighted distance between them can be considered and how their actions is as follow that each cell on a primary network which amount of costs or cells show resistance movement, as see in
iii) Determining optimum path: The accumulative cost has been created in previous step, on this stage use to determine the optimum path all points of cost surface. According to
After determination of optimum path, the cost analyze result of GIS designed path and Alborz province water and wastewater company path, illustrated on
Constructing water transition pipelines, one of the most important activities of water and wastewater industry of country which with due to high cost and pipeline environmental interaction effects on the other hand, cause consider several different parameters in this case study and because in path finding process, the parameters are not independent and they have interact and feedbacks together, which necessity to use Multi-Criteria Evaluation (MCE) method as one of the decision support methods in GIS. There for considering these parameters simultaneously could achieve to better output instead of these parameters independent and separately. The result achieved from this study demonstrate the importance of MCE and effect of weighting factors in network method and spatial analyze, so that by ignoring influential factors, cost and exploitation time from pipeline. For this reason, the purpose of research focus on determination optimum path of water transition pipelines from Taleghan’s Dam to Hashtgerd New City, by the way tried at first by using analysis capabilities in GIS environment, IDRISI Selva and applying water and wastewater technical section expert’s suggestions, optimum path determined.
Then the optimum path and proposed path by Alborz province water and
Pipelines pass expense from land use (dollar) | ||||
---|---|---|---|---|
agriculture | garden | agriculture | garden | |
10,981,847.2955 | 3,987.0917 | 60,039,328 | 50.862 | Optimum path |
6,042,187.886 | 6,042,187.886 | 345,968,208 | 12,311.5176 | Alborz province water and wastewater company |
Sum total costs (dollar) | Destruction price of asphalt cover because of pipelines intersection with road (dollar) | Price cut until 4 depth (dollar) | Total price (dollar) | Length (km) | |
---|---|---|---|---|---|
11,158,679.932 | 75,939.5348 | 32,039.9529 | 28,982.2315 | 35 | Optimum path |
12,975,209,225.08074 | 119,601.2646 | 37,255,691.1377 | 337,002.0757 | 40.6976 | Alborz province water and wastewater company |
wastewater company compared in technical and engineering, ecological and sumptuary point of view. By comparing two linear schemes imply that expense pf optimum path only by applying influential of some layers increase rather than water and wastewater path. Two path compared based on total cost and show that optimum path rather than water and wastewater path 14% decrease expense and extra cost mostly due to the more intersection between pipeline with river and road, pass unauthorized areas and personal parcels which need to pay and pass through different land use areas cause to increasing cost and pipeline’s length which role main obstacle for execute process while the proposed path achieved from this research executable. In this research, worth of delay time and influence of obstacle factors expressed scientifically and mathematical simplified and prepared for pre-execute.
As each region has special properties proposed in this research use other method like genetic algorithm for path finding and there for result analyze until best path base of technical and engineering parameters, bio-ecological, sumptuary distinct and execute.
Arabi, M. and Gharehhassanloo, S. (2018) Application and Comparison of Analytical Hierarchy Process (AHP) and Network Methods in Path Finding of Pipeline Water Transmission System, from Taleghan’s Dam to Hashtgerd New City, Tehran, Iran. Open Access Library Journal, 5: e4303. https://doi.org/10.4236/oalib.1104303