Transcript Slide 1

Using of Fuzzy AHP Based Multi Criteria Weighting
Scheme for GIS Routine in National Iranian Gas
Payam Moradi
Young Researchers Club
Azad University of Tafresh , Iran
Eleventh International Conference on Fuzzy Set Theory and Applications
(FSTA 2012)
Outline

INTRODUCTION

METHODOLOGY
A.
G.
Finding Pipeline Routing Criteria
Selection of Factors Affecting the Route in National Iranian Gas Engineering
&development Company
Refinement of criteria
Fuzzy TOPSIS model
Assigning Weights to the Variables
The FAHP and methodology
Finding the Pipeline routing by using weighting

RESULTS AND DISCUSSION
B.
C.
D.
E.
F.
1- Introduction
• The overall objective in selecting a petroleum pipeline route is choosing the
shortest, most direct route is always a goal for capital expenditure reasons, but many
important goals exist simultaneously in the route selection project and at times these
goals may conflict. Geophysical, environmental, political, social, economic, and
regulatory factors interact to define the route possibilities
• Pipeline alignment is an optimization between several factors such as social
issues, environmental issues, and cost of the project and so on.
Methodology :
A:
Finding Pipeline Routing Criteria
Establish the shortest possible route connecting originating, intermediate,
and terminal locations;
Avoid populated areas for public safety reasons
Avoid hilly or rocky terrain;
Avoid areas with steep slopes
Avoid areas with high land cost
Methodology :
Keep rail, road, river, and canal crossings to the bare minimum;
Avoid a route running parallel to high-voltage transmission lines or DC
circuits;
 Use an existing right-of-way, if possible;
 Avoid other obstacles, such as wells, houses, orchards, lakes, or ponds.
 Avoid unfavorable soil type
 Avoid reserved forest areas
B : Selection of Factors Affecting the Route in National
Iranian Gas Engineering & development Company
The first step in a routing process is the selection of the factors affecting the
pipeline route. Several spatial and non spatial factors affect the pipeline
routing.
1 ) Operability :
2 ) Environmental Issues :
3 ) Economic :
C : Refinement of criteria
 TOPSIS method is based on choosing the best alternative,
which has the shortest distance from the positive-ideal solution
and the longest distance from the negative-ideal solution
 the concept is rational and comprehensible
 the computation involved is simple
 the concept allows objective weights to be
incorporated into the similarity process
D:
Fuzzy TOPSIS model
The Fuzzy MCDM can be concisely expressed in matrix format :
where
Xij : is the performance rating of the alternative
Ai : respect to the jth criterion
Cj and wj : represents the weight of the jth criterion
Cj : The normalized Fuzzy decision matrix denoted by R is shown below
The weighted Fuzzy normalized decision matrix is shown in
the proposed Fuzzy TOPSIS procedure is then as follows :
Step1: Decision matrix is normalized
Step2: Weighted normalized decision matrix is formed
Step3: Positive ideal solution (PIS) and negative ideal solution (NIS) are
determined
Step4: The distance of each alternative from PIS and NIS are Calculated :
Step5: The closeness coefficient of each alternative is Calculated
Step6: By comparing i CC values, the ranking of alternatives are
determined.
E : Assigning Weights to the Variables
A weighting system has to be devised for weighing each of the map layers.
The weighting system forms the backbone of the methodology .The weighted
Layers are all summed up to form the suitability layer
F:
The FAHP and methodology
Step 1: The fuzzy synthetic extent value ( Si ) with respect
criterion is defined in
=
Step 2: The degree of possibility of
=
=
is defined in
This expression can be regularly written as given in
to the
Step3 :
The degree possibility for a convex fuzzy number to be greater than k convex fuzzy
numbers
can be defined by
Assume that is:
Then the weight vector is given in
Step4 : Via normalization, the normalized weight vectors are given in
Where W is non-fuzzy numbers
Statement
Absolute
TFN
(5/2,3,7/2)
Very Strong
(2,5/2,3)
Fairly Strong
(3/2,2,5/2)
Week
Approximaly
Equal
Equal
(1,3/2,2)
(1/2,1,3/2)
(1,1,1)
G:
Finding the Pipeline routing by using weighting
Necessary steps in GIS include:
Data Sources
Data Input




Acquiring topographic maps of the target Area
Acquiring satellite imagery of the area
Identification of factors affecting the route.
Creating new layers for the analysis
Data Processing
Assigning Weights to the Variables
Raster Data Analysis
Vector Data Analysis: Processing the data, weighting and Overlay
Raster Data Analysis: Suitability layer, Cost distancing and Cost direction
RESULTS AND DISCUSSION