Use of a Combination of MRSS-ANP for Making an Innovative Landfill Siting Decision Model

14 Pages·2015·2.46 MB·English

Hindawi Publishing Corporation
Mathematical Problems in Engineering
Volume 2015, Article ID 381926, 13 pages
http://dx.doi.org/10.1155/2015/381926
Research Article
Use of a Combination of MRSS-ANP for
Making an Innovative Landfill Siting Decision Model
MohammadK.Younes,1N.E.AhmadBasri,1Z.M.Nopiah,1
H.Basri,1andMohammedF.M.Abushammala2
1DepartmentofCivilandStructuralEngineering,UniversitiKebangsaanMalaysia,43600Bangi,Selangor,Malaysia
2DepartmentofCivilEngineering,MiddleEastCollege,KnowledgeOasisMuscat,P.B.No.79,124AlRusayl,Oman
CorrespondenceshouldbeaddressedtoMohammadK.Younes;[email protected]
Received4April2015;Revised7June2015;Accepted8June2015
AcademicEditor:JurgitaAntucheviciene
Copyright©2015MohammadK.Younesetal.ThisisanopenaccessarticledistributedundertheCreativeCommonsAttribution
License,whichpermitsunrestricteduse,distribution,andreproductioninanymedium,providedtheoriginalworkisproperly
cited.
Landfillsitingisacomplex,multicriteriadecision-makingproblemthatneedsanextensiveevaluationofenvironmental,social,
landuse,andoperationalcriteria.Integrationofamedianrankedsampleset(MRSS)andananalyticnetworkprocess(ANP)has
beenimplementedtoranktheassociatedcriteriaandselectasuitablelandfillsite.Itminimizestheuncertaintyandthesubjectivity
ofhumanjudgments.Fourgroupsofexpertswithdifferentbackgroundsparticipatedinthisstudy,andeachgroupcontainedfour
experts.Therespondentpreferenceswererankedina4-by-4matrixtoobtainthejudgmentsetsfortheMRSS.Thesesetswere
subsequentlyanalyzedusingANPtoobtaintheprioritiesinthelandfillsitingcriteria.Theresultsshowthatlandtopologyand
distancefromsurfacewaterarethemostinfluentialfactors,withprioritiesof0.18and0.17,respectively.Theproposedintegrated
modelmaybecomeapromisingtoolfortheenvironmentalplannersanddecisionmakers.
1.Introduction widens its popularity and strengthens it [10], but analyzing
andhomogenizingthepreferencesofthesestakeholdersare
Facilitysiteselectionmodeliscomplexandneedsextensive complexissue,especiallywithconflictofinterestsamongthe
assessmentandcomparisonefforts[1].Properlandfillsiting participatedinterestgroups.
isessentialtoreducetheenvironmentalandhealthimpacts Decision support systems like the analytic hierarchy
associatedwithitsconstructionandoperation[2].Ingeneral, process(AHP)anditsgeneralization(ANP)havebeenwidely
solid waste treatment and disposal facilities belong to a implementedtohandlethecomplexproblems.Multicriteria
group of obnoxious or undesirable facilities, and, therefore, decision-making (MCDM) using ANP is composed of the
landfillsitingfacestwomajorchallenges:(i)socialobjection following steps: (i) identifying the factors and the compo-
represented by a phenomenon known as BANANA (build nents within the network together with their interactions
absolutely nothing anywhere near anyone) or NIMBY (not and relations; (ii) conducting pairwise comparisons among
in my back yard) and (ii) the large number of technical, the network elements and the main/subcriteria to build
social, and environmental factors that must be considered the unweighted supermatrix; (iii) obtaining the weighted
in selecting the best location to minimize nuisances and supermatrix via weighting the blocks of the unweighted
maximize efficiency and social acceptance [3]. Solid waste supermatrix by the corresponding priorities of the clusters
landfill remains a convenient method for the disposal of (fromwhichtheresultingmatrixiscolumnstochastic);and
an increasing amount of municipal solid waste, notably in (iv) developing the limit matrix by increasing the power of
developing countries [4]. Landfill site selection requires a theweightedsupermatrixuntiltheweightsconverge[11].
differenttypeofcriteriaprocessingtoaccountfortheunequal TheANPisimplementedtodrivetherelativeprioritiesof
criteria importance [5–9]. Moreover, increasing the num- thecriteriausingthejudgmentofindividuals[12].However,
ber of participating parties in the decision-making process ANPimplementationrequireshighernumberofjudgments
2 MathematicalProblemsinEngineering
Table1:Definitionofthescaleofimportance[58].
Intensityofimportance Definition Explanation
9 Extremelyimportant Thisactivityisofthehighestpossibleorderofaffirmation
7 Stronglyimportant Thisactivityisstronglyfavored(dominant)overotheractivities
5 Moderatelyimportant Thisactivityismoderatelyfavoredoverotheractivities
3 Slightlyimportant Thisactivityisslightlyfavoredoverotheractivities
1 Equallyimportant Thisactivityequallycontributestotheobjective
2,4,6,and8 Intermediateimportancebetweentwoadjacentresponses
than AHP. Because of the ability of ANP to treat the 2.Methodology
interactionsandfeedbackandthusjustifythedecision[13],
ANP is widely used in many decision-making applications. Landfillsitingisamulticriteriadecision-makingprocess.The
However,ANP-baseddecisionsarelimitedbytheuncertainty proposed model decomposes this process into three levels:
injudgmentduringthepairwisecomparison[14].Aprevious problem construction, criteria analysis, and selection [7].
study [1] combined ANP and data envelopment analysis Problem(case)constructiondeterminestheproblem,aims,
to leverage both the available qualitative and quantitative assessment criteria, the experts, and their groups. Criteria
data for the location of a landfill site. Additional studies analysis extracts the expert knowledge and performs data
[15, 16] implemented ANP to suggest the best location of analysis using MRSS. The selection step determines the
a landfill site. Several researchers [17, 18] integrated a fuzzy importanceofthelandfillsitingcriteriausingANPandthe
set,AHP,andaweightedlinearmethodtoprioritizethesite rankofthefinalpriorities.
evaluationcriteriaandappliedthisprocessusingGeographic
InformationSystem(GIS)software.Moreover,hybridmodel 2.1.CaseConstruction. Theproblemconstructionstartswith
ofanANPandatriangularfuzzyfunctionwereusedby[14]to a literature review used to determine the main and sub-
measureremedialcountermeasures.Alandfillsitesuitability criteria of the landfill site selection. There are no general
analysis using an AHP and a compromised programming approachestoselectasetofevaluationcriteriabutitcanbe
methodwasalsoreported[19].AnAHPwasappliedtofind selected through an examination of the relevant literature,
theweightedsiteevaluationcriteriaandwasusedinGISto analysisstudy,andexpertopinions[29].However,thecriteria
suggestthebestlandfilllocation[20]. selection was based on the usage (the most commonly
The ranked sample set (RSS) was first proposed by Mc found in literature), expert opinions, and data availability.
Intyre in 1952 to estimate the population mean, and since These criteria were subsequently arranged in a hierarchi-
thattimeitwasmodifiedanddevelopedmanytimes[21,22]. cal structure, and the hierarchical tree defines the most
Applying of the RSS to estimate the population mean and general network. The landfill siting criteria were classified
medianleadstonotablegainsinprecision[23].TheMRSSis into four main groups: social [30, 31], operational [16, 18],
anadaptationofRSS,and,inthismethod,onlythemedian environmental[32,33],andlanduse[34–36].Moreover,the
observation is considered from each of randomly selected subcriteriafallundereachmaingroup,asshowninFigure1.
sets. The MRSS is advantageous (relative to RSS) because it After the initial classifying, the experts were determined
minimizes the ranking errors and enhances the estimation and divided into four clusters (groups). A cluster analysis
efficiency [24]. The MRSS proposes promising applications splits the data into meaningful groups that are usually
in environmental researches because of its capability to associatedorsharecharacteristics[37].Theresultinggroups
represent a population without extensive observations [25]. involved the governmental sector, private sector, academia,
For instance, the spray deposits on the leaves of apple trees and nongovernment organizations interested in solid waste
were assessed using RSS [26]. An RSS method was also andenvironmentalissues.
appliedtocollectsamplesfromgasolinestationsforanalysis A developed questionnaire asked the stakeholders to
intended to verify the conformity of these stations with draw pairwise comparisons among the criteria and the
cleanairregulations[27].Priorsampleknowledgewasalso subcriteria with respect to landfill site selection. The used
integrated with RSS to minimize the cost of evaluating a questionnaire takes into account the interactions and feed-
streamhabitatregionforsalmon[28]. backsbetweenthecriteria.Table1showstheintensityofthe
This study presents a model to reduce the imprecision importanceofthecriteria.Theodd-numberedrankingswere
and vagueness of the human decision-making. It identifies usedtodeterminethecriteriaimportance,whereastheentire
the relative importance of landfill siting criteria as a case rangefrom1to9wasusedtodeveloptheANPmulticriteria
study. The presented model leverages the power of an decisionanalysis.
expert system to extract knowledge that is subsequently
appliedtoahybridMRSS-ANPsystemtoobtainthecriteria 2.2. Criteria Analysis. The stakeholders preferences were
weights. grouped into four random sets. Each set consists of the
MathematicalProblemsinEngineering 3
Determining the priorities of the landfill siting criteria
Objective
criteria
Social Environmental Land use Operational
Depth of ground
Proximity to water Proximity to
nearest critical sites Landfill area
settlement
Proximity to
surface water
Soil cover
eria availability
crit Aesthetics Fault zones Road
Sub (rock cracks) accessibility Haul distance
Topology (Terrain)
Figure1:Hierarchicalstructureofthelandfillsitingcriteria.
Table 2: Comparison of the importance of land use with the 2.3. Final Priority Selection. The study aim is to determine
importanceofoperationmethods. the overall priority of each criterion and apply it in the
case study considering the interactions and the feedbacks
Private
Sector Government NGO Academia amongthemainandsubcriteria.ANPsystematicallybreaks
sector
downtheproblemtojustifythedecision[38,39].Tocapture
Expertgroupnumber1 7 0.33 0.20 1
the interactions and feedback, a hierarchical framework
Expertgroupnumber2 1 3 1 0.14 that contains all main and subcriteria must be constructed.
Expertgroupnumber3 7 5 3 7 Thus the comparisons can be performed and synthesized
Expertgroupnumber4 3 3 3 0.20 to determine the unweighted, weighted, and limit matrices
that determine the priorities of importance of the landfill
sitingcriteria.Figure2showstheinteractionsandfeedback
responses of one government, private, academia, and NGO between the landfill siting components. An arrow and/or
respondent.Therespondentsareexpertsinthefieldofsolid loop arrow specify the dependence and feedback for which
waste management and landfill siting issues through their thetwo-side(double)arrowsindicatetheinfluencesbetween
work experience. Table2 shows an example of one of the theelementsonbothgroups.Theinner-dependenceorself-
comparisons by displaying the obtained preferences of the feedbackisindicatedbyalooparrowatthetopofeachgroup.
respondentsandtheirsets.Next,theseresponseswereranked Theresultingrelativeimportancesetsfromtheprevious
in increasing order for each individual set, as shown in step contain the preferences of government, private, NGO,
Table3.Afterthat,theimportanceofthelandfillsitingcriteria and academic stakeholders and are used in the ANP. This
wasobtainedusingthesecondscenario[21]: step is repeated for the sixty-three pairwise comparisons
to build the comparison matrix (unweighted supermatrix).
(i)If the sample size, 𝑛, is odd, then the median is The inputs of the supermatrix depend on the presence and
selected by ((𝑛 + 1)/2)th. This observation can be the type of dependence among the group elements that are
denotedas𝑋(((𝑛+1)/2):𝑛),andthegeneralformulais shown in Figure2. The matrix is subsequently input into
the Super Decisions (version 2.2) software to develop the
{𝑋(((𝑛+1)/2):𝑛)1,𝑋(((𝑛+1)/2):𝑛)2,...,𝑋(((𝑛+1)/2):𝑛)𝑛}. (1) weightedandlimitmatrices[40].Theweightsobtainedinthe
limitmatrixrepresentthefinalimportancepriorities.Finally,
(ii)Ifthesamplesize𝑛iseven, the integrated landfill siting procedures are summarized
in Figure3. This figure illustrates the guidelines for such
thenthemedianisselectedby(𝑛/2)th.Thisobservationcan
decision-makingproblem.
bedenotedas𝑋((𝑛/2):𝑛),andthegeneralformulais
2.4. Case Study. Selangor is the most populated and highly
{𝑋((𝑛/2):𝑛)1,𝑋((𝑛/2):𝑛)2,...,𝑋((𝑛/2):𝑛)𝑛}. (2) developed state in Malaysia; it has a diversified economy
4 MathematicalProblemsinEngineering
Operational criteria
Landfill area Soil cover Haul distance
availability
Land use criteria
Social criteria
Distance from Road Distance from
Aesthetics nearest settlement accessibility critical sites
Environmental criteria
Topology Depth of
Fault zones Distance from surface
(Terrain) (rock cracks) water ground water
Figure2:Interactionsandfeedbackbetweencriteria.
including industry, commerce, agriculture, and tourism. 3.ResultsandDiscussion
Moreover,Selangorcompletelysurroundstwo federalterri-
tories, which are Kuala Lumpur (KL), the national capital 3.1.CaseConstruction. Figure1showsthedevelopedhierar-
of Malaysia, and Putrajaya the federal capital. The areas of chical structure of the landfill site evaluation criteria. Each
Selangor, Kuala Lumpur, and Putrajaya are 7,930, 243, and main criterion has an ultimate goal, that is, to maximize
2 the preservation of nature (environmental), acceptance by
92km , respectively. There is a great demand to depend on
thepublic(social),orappropriatenessofthesite(landuse).
scientificapproachfordeterminingalandfillsiteinSelangor
Additionally,thetargetofoperationalcriteriaisminimizing
due to increasing amounts of solid waste and land scarcity.
the costs. The eleven subcriteria that share common char-
Thus Boolean logic was implemented to exclude unsuitable
acteristics were grouped together under the main criteria.
areasthatcannotbeusedasadisposalsite[19].Theexclusion
Sincethesolidwastehaulingdistance,availabilityofsoilcover
is done by overlaying technique and in dependence on
for daily landfill operations, and landfill area are controlled
constraintfactors[6,41];thesefactorsarebasedonMalaysian
duringlandfillconstructionoroperation,theywereclassified
guidelines for development of solid waste sanitary landfill
underonegroup(operational)[43].
[42].However,theBooleanlogicisrestrictiveinnature[43];
Moreover, land use involves the locations of critical
thus, by its implementation,the study area is classified into
two classes suitable area with value (1) and unsuitable area sites highways and roads that are identified by the town
planningdepartmentandtheselocationsarehighlightedfor
withvalue(0)asshowninFigure4anddescribedin(3):
specific consideration in future plans. Examples of critical
𝑛 sitesincludeairports,hospitals,railway,andotherinstitutes
Boolean Suitablity Index=∏𝑏𝑗, (3) [18]. Landfills serve large communities, but only subset of
𝑗=1 those communities commonly experiences the impacts of
where Boolean Suitability Index has a value (0 or 1), 𝑏𝑗 is the landfill (typically the ones that are located near it)
[44]. However, these effects can be minimized using spe-
the Suitability Index for each constraint criterion and has a
value (0 or 1), and 𝑛 the total number of constraint criteria cial arrangements designed to reduce the nuisances caused
during waste transportation and enhance the landscaping
[2]. Finally, the potential landfill sites were suggested based
aroundthelandfilltocreateagreenbuffer.Theenvironmental
on assumed landfill area and ranked using the obtained
criteriaaimtoconserveair,water,andsoilandtominimize
MRSS-ANP weights andSuitabilityIndex (SI), which isthe
land altering activities [32] by applying the best available
sumofproductsofthestandardizedscoreofeachcriterion
techniques and environmental practices to achieve these
multipliedbytheweightofeachcriterion:
goals.
SI=∑𝑊𝑖∗𝐶𝑖, (4) Figure2 displays the dependence and feedback among
the criteria. The environmental criteria do not relate to the
where 𝑊𝑖 is weight of factor 𝐼 and 𝐶𝑖 is criteria grading of aestheticsordistancefromthenearestsettlement;therefore,
factormap𝑖[34]. an interconnection or feedback between the environmental
MathematicalProblemsinEngineering 5
Target (landfill siting)
Main and subcriteria
based on data
Data Constraints
availability and
collection based on Malaysian
experts opinions
guidelines
Build decision tree
Prepare survey
Georeferencing and
digitizing
Expert group constraints and main
and subcriteria
Government Private Academia NGO
Expert preference matrix
Boolean
logic
MRSS preference set analysis
ANP
Restricted area
map
Potential locations
Criteria
map
weight
Ranked landfill sites
Figure3:Thelandfillsiteselectionalgorithm.
and social main group is not shown. One or more of the private, academia, and NGO. Therefore, the response range
remaining subcriteria relate to an additional criterion from withinthesamesetisrelativelylargebecauseoftheconflicts
outside of the group. For example, reciprocal effects were of interest of the stakeholders. The expert responses within
notedbetweenthelandtopologyandsurfacewater.Surface the same group were observed to converge, but outlier
water alters the land topology, whereas the topology affects responseswerenotedduetohumannatureandthevarious
thewaterrunoffandmaximizesorminimizesthemovement backgroundsoftheexperts.Forinstance,onegovernmental
ofpollutants.Pairwisecomparisonswereusedtocomparethe expertmightemphasizeenvironmentalconcernsbecauseof
personalinvolvementinenvironmentalregulations,whereas
criteriaandtoallocatethecriteriaprioritiesusingtheSaaty
another governmental expert may emphasize planning and
method [39, 45]. The respondents were divided into four
land development because of personal involvement in a
stakeholdersetstoreducevaguenessandenhancequality.
planning department. Similarly, one NGO representative
could emphasize conservation, whereas another NGO rep-
3.2.CriteriaAnalysis. Basedontheinteractionsandfeedback resentative might emphasize service to society. Therefore,
among the criteria, sixty-three pairwise comparisons were pointsofviewcandivergewithinanidenticalgroup.
required.Thepreferencesofeachrespondentwererecorded Sixty-three pairwise comparisons were performed to
for each comparison. Every set of responses contained the identifytherelativeimportanceofthelandfillsitingcriteria.
opinionofoneexpertfromeachgroup,thatis,government, AnexampleofoneofthesecomparisonsisshowninTable2.
6 MathematicalProblemsinEngineering
Potential landfill locations Table 3: Ranked comparison of the importance of land use with
operationalmethods.
N
Rankedexpertspreferences
Expertgroupnumber1 0.20 0.33 1 7
Expertgroupnumber2 0.14 1 1 3
Expertgroupnumber3 3 5 7 7
Expertgroupnumber4 0.20 3 3 3
Table4:Prioritiesgroupmatrixofthemaincriteria.
Sector Landuse Environmental Operational Social
Landuse 0.183 0.143 0.116 0.540
Environmental 0.526 0.571 0.488 0.0
Operational 0.204 0.286 0.275 0.163
Social 0.087 0.0 0.121 0.297
Selangor state Table5:Finalprioritiesofthemaincriteria.
Landfill potential area
Maincriteria Finalpriority
(a)
Landuse 0.142
Environmental 0.546
Operational 0.262
Social 0.05
Theweightedsupermatrixclarifiesthevaluesofeachgroup
Selangor and its elements. The limit matrix represents the priorities
results and is obtained by raising the weighted supermatrix
Restricted area
toahighpowertoacquireconstantvalues.
Table4 shows the priorities group matrix. Zero values
0 15 30 60 90 0 15 30 60 90
meanthattherearenointerconnectionsbetweenthecriteria
(km) (km) in the matrix; this independence is shown in Figure2 in
which no interactions are displayed between the environ-
(b) (c)
mental and social groups. The priority value of each main
Figure4:Selangorandpotentiallandfillsitesmaps. criterioninTable4dependsontherelationshipbetweenthe
criteriagroups.Forinstance,operationshaveanimportance
of 0.286 with respect to minimizing the landfill effects on
the environment. This importance decreases to 0.16 when
This table compares land use and operational methods to considering the creation of a positive social opinion with
createapositivesocialimpressionwithrespecttothelandfill respecttothelandfillsite.
site. For instance, the second expert in the first group Thefinalprioritiesofthemaincriteriagroupareshown
indicates that operation method is slightly more important in Table5, and the highest rank of 0.54 is shown for
thanthelanduse.InTable3,therelativeweightsareranked environmentalcriteria,followedbyoperationalmethodsand
in increasing order. Because four preferences are contained techniques(priorityrankof0.26).Alandfillshouldbelocated
in each set, the median weight set is determined using (2). and designed to protect human health and to conserve the
Therefore, the second and the third quarters represent the environment. Therefore, environmental criteria gained the
MRSS and determine the relative importance set of the highestrankandthisisthepresentworldwidetrend[29].In
landfill siting criteria. The obtained relative importance set addition,accordingtotheobtainedresultswecanconclude
displayedinTable3is“1;5;7;3.”Thistechniqueguarantees that the social and operational criteria are considered to
representationof the best set regardless of the origin of the beinsignificantbystakeholders.However,suchresultswere
responses. This result is displayed in Table3 in which an reported by many researchers. For instance, Ismail (2011)
increasingresponserankisrequiredregardlessofthesector. [46] reported ground water, surface water, and protected
area as the most important factors followed by land slope.
3.3. Final Priority Selection. The ANP uses three matri- Afzalietal.(2011)rankedthesurfacewater(19%)followedby
ces: unweighted supermatrix, weighted supermatrix, and groundwater(13%)asthemostimportantphysicalcriteria.
limit matrix. The unweighted supermatrix is the relative Nadi et al. (2010) [47] ranked the hydrology and water as
importance of all main components and subcomponents. themostimportantcriteria(33.4%)andsocialandfinancial
MathematicalProblemsinEngineering 7
Table6:Weightprioritiesoftheoverallsubcriteria.
Prioritynormalized
Group Criteria Finalpriority
bygroup
SW 0.317 0.173
GW 0.157 0.085
Environmental
FZ 0.181 0.099
TO 0.345 0.188
CS 0.409 0.058
Landuse
RA 0.591 0.083
HD 0.145 0.038
Operational LA 0.511 0.135
SA 0.344 0.091
AE 0.579 0.029
Social
NS 0.421 0.021
SW:proximitytosurfacewater,GW:depthofgroundwater,FZ:proximitytofaultzone,TO:topology,CS:proximitytocriticalsite,RA:roadaccessibility,HD:
hauldistance,LA:landfillarea,SA:soilavailability,AE:aesthetic,andNS:nearestsettlement.
Table7:SummaryoftherankingsandSIforthepotentiallandfillsites.
Environmental Landuse Operational Social
Sitenumber SI
SW GW FZ TO CS RA HD LA SA AE NS
LF1 0.173 0.085 0.040 0.113 0.058 0.017 0.038 0.135 0.091 0.029 0.004 0.782
LF2 0.173 0.068 0.040 0.113 0.058 0.083 0.038 0.135 0.091 0.029 0.004 0.832
LF3 0.035 0.017 0.020 0.188 0.058 0.083 0.038 0.135 0.091 0.029 0.008 0.702
LF4 0.138 0.068 0.099 0.113 0.058 0.083 0.038 0.135 0.091 0.023 0.013 0.859
LF5 0.104 0.085 0.020 0.075 0.058 0.066 0.038 0.135 0.091 0.017 0.021 0.711
LF6 0.138 0.051 0.040 0.150 0.058 0.064 0.038 0.135 0.091 0.017 0.004 0.787
LF7 0.035 0.017 0.099 0.113 0.058 0.083 0.038 0.135 0.091 0.029 0.008 0.706
criteria as the least important criteria with weight equal to thirdhighestrankisforlandfillarea(13.5%);thisrankingis
15.5%and15.3,respectively.Demesoukaetal.(2013)indicated duetotherequirementtolocatethelandfillinamannerthat
thehydrologyasthemostimportantfactorfollowedbythe reducesthepriceofthelandbecausethelandpricerepresents
environmentalcriteria and ranked the social and economic thehighestcostforalandfill.Inaddition,thelandfillsizemust
factors as the least important or insignificant factors. In a beoptimizedtominimizeenvironmentaleffectsandthecosts
study done by [48], the social and technoeconomic criteria associatedwithidentifyinganewlandfillsite.
gained the lowest importance of 9% and 6%, respectively. However, applying (2) produced Table8 that describes
Moreover, such conclusion was also reported by Ismail thepreferencesetsoftheperformedsixty-threecomparisons.
(2011) for landfill siting in Malaysia because the social and Each element in the set represents the preferences of each
operational (technical) criteria can be extended and mod- expert group. Table9 is a result of applying the preferences
ified. A study done by [49] reported that urban area and sets in ANP and represents the unweighted supermatrix. It
water resources are the most important criteria that should is two-dimensional matrix of element by element, and it
be considered for construction intermunicipality landfill. providesrelativeimportanceofallcomponents(maincriteria
However, sometimes it is inappropriate to compare among and subcriteria) [45]. The weighted and limit matrices are
studiesfromdifferentcountriesbecausetheobtainedweights describedbyTables10and11,respectively.Inthelimitmatrix,
aredependentuponsurveyedrespondents,differentstudied the constant values of each value are determined by taking
factors,anddifferentlocalandenvironmentalconditions. thenecessarylimitoftheweightedsupermatrix[38].Social
The final priorities of the factors related to landfill site criteriaandhauldistancegotthelowestrank.Theinfluenceof
selection are shown in Table6. The overall highest rank thesecriteriaonthedesignofalandfillcanbeminimizedwith
is for land topology (18.8%) because of its direct effect suitable arrangements. For example, if appropriate transfer
on both surface water and groundwater as well as on soil stationisused,thenthesolidwastehaulingcostisreduced.
erosion by control of water runoff [50]. Surface water is Additionally, planted buffer zones and special landscaping
the second highest factor (17.3%). Surface water can easily can reduce visual and odor pollution to minimize the nui-
becomepollutedandcanthereforepropagatepollutants.The sancetoneighbors.Moreover,shiftingtrafficasfaraspossible
8 MathematicalProblemsinEngineering
Table8:MRSSpreferencesets.
Number Comparisontarget Comparisonelements MRSSpreferencesets
1 Landuse(operational) 0.33,1,7,and3
2 Tocreatepositivesocialopinion Landuse(social) 1,1,5,and1
3 Operation(social) 0.2,1,0.2,and1
4 Environmental(landuse) 1,3,5,and5
Toprotectenvironmental
5 Environmental(operational) 1,1,5,and1
elements
6 Landuse(operational) 1,1,5,and1
7 Environmental(landuse) 1,3,3,and3
8 Environmental(operational) 1,1,7,and3
9 Forsustainableandstrategicland Environmental(social) 5,1,7,and7
useplanning
10 Landuse(operational) 0.33,0.2,1,and3
11 Landuse(social) 1,0.14,3,and3
12 Operation(social) 1,1,5,and5
13 Environmental(landuse) 1,7,5,and5
14 Tominimizetheoperationalcost Environmental(operational) 1,1,3,and3
15 andtooperatethelandfillwith Environmental(social) 1,1,5,and3
bestavailabletechniquesand
16 Landuse(operational) 0.33,1,1,and1
bestenvironmentalpractices
17 Landuse(social) 1,0.2,3,and1
18 Operation(social) 5,1,5,and3
19 Proximitytocriticalsites(roadaccessibility) 0.2,0.11,0.33,and1
20 Soilcoveavailability(landfillarea) 0.33,1,5,and1
21 Toprotectsurfacewater Avoidingfaultingzones(depthofgroundwater) 0.33,0.14,3,and1
22 Avoidingfaultingzones(topology) 1,0.14,3,and1
23 Depthofgroundwater(topology) 3,1,1,and1
24 Landfillarea(soilcover) 1,0.2,5,and3
25 Toreducetheeffectsonfault Proximitytosurfacewater(depthofgroundwater) 1,1,3,and1
26 zones Proximitytosurfacewater(topology) 1,1,1,and1
27 Depthofgroundwater(topology) 1,1,1,and1
28 Landfillarea(soilcover) 1,1,5,and1
29 Toprotectthegroundwaterfrom Proximitytosurfacewater(avoidingfaultzones) 1,1,1,and1
30 pollutants Proximitytosurfacewater(topology) 1,1,0.2,and0.3
31 Avoidingfaultzones(topology) 1,1,5,and3
32 Landfillarea(soilcover) 1,0.14,3,and1
33 Toreducealteringtheland Proximitytosurfacewater(avoidingfaultzones) 1,1,3,and3
34 topology Proximitytosurfacewater(topology) 1,1,1,and1
35 Avoidingfaultzones(topology) 1,0.2,0.33,and1
36 Proximitytosurfacewater(avoidingfaultzones) 1,1,5,and1
37 Proximitytosurfacewater(depthofgroundwater) 1,1,5,and7
38 Toprotectthecriticalsites Avoidingfaultzones(depthofgroundwater) 1,1,3,and3
39 Aesthetic(proximitytolivingsettlement) 0.33,1,5,and3
40 Roadaccessibility(proximitytocriticalsites) 0.33,1,1,and3
41 Proximitytosurfacewater(topology) 0.33,1,0.2,and0.2
Tolocatelandfillinplaceseasily
42 HaulDistance(landfillArea) 5,5,5,and5
accessedbyroads
43 Aesthetic(proximitytolivingsettlement) 0.33,1,3,and1
44 Proximitytosurfacewater(topology) 1,3,5,and1
45 Tominimizethesolidwastehaul Proximitytocriticalsites(roadaccessibility) 0.33,0.2,0.2,and0.14
46 distance Landfillarea(soilcover) 1,1,1,and1
47 Aesthetic(proximitytolivingsettlement) 0.33,0.3,1,and1
MathematicalProblemsinEngineering 9
Table8:Continued.
Number Comparisontarget Comparisonelements MRSSpreferencesets
48 Proximitytosurfacewater(avoidingfaultzones) 1,1,3,and3
49 Proximitytosurfacewater(depthofgroundwater) 1,1,3,and5
50 Proximitytosurfacewater(topology) 3,1,7,and7
51 Avoidingfaultzones(depthofgroundwater) 1,1,3,and3
52 Avoidingfaultzones(topology) 3,1,7,and3
Todeterminetheoptimum
53 landfillarea Depthofgroundwater(topology) 0.33,1,3,and3
54 Proximitytocriticalsites(roadaccessibility) 1,1,3,and5
55 Solidwastehauldistance(landfillarea) 1,1,1,and5
56 Solidwastehauldistance(soilcover) 1,1,3,and3
57 Landfillarea(soilcover) 0.33,1,5,and1
58 Aesthetic(proximitytolivingsettlement) 0.33,1,1,and1
Toprotectthesoilcoverfrom
59 Proximitytosurfacewater(topology) 0.33,1,0.2,and0.33
pollution
60 Proximitytocriticalsites(roadaccessibility) 0.33,0.33,1,and1
Tominimizethepossibilityof
61 Solidwastehauldistance(landfillarea) 1,1,3,and1
thelandfillbeingseen
62 Aesthetic(proximitytolivingsettlement) 1,0.33,3,and1
Tolocatethelandfillasfaras
63 Solidwastehauldistance(landfillarea) 1,1,7,and7
possiblefromsettlements
Table9:Unweightedsupermatrix.
Environmental Landuse Operational Social
Grouplabels
SW GW FZ TO CS RA HD LA SA AE NS
Environmental
SW 0.00 0.25 0.41 0.40 0.54 0.25 0.75 0.48 0.25 0.00 0.00
GW 0.55 0.00 0.26 0.00 0.16 0.00 0.00 0.15 0.00 0.00 0.00
FZ 0.21 0.46 0.00 0.20 0.30 0.00 0.00 0.29 0.00 0.00 0.00
TO 0.24 0.28 0.33 0.40 0.00 0.75 0.25 0.08 0.75 0.00 0.00
Landuse
CS 0.25 0.00 1.00 0.00 0.33 1.00 0.17 0.75 0.00 0.33 0.00
RA 0.75 0.00 0.00 1.00 0.67 0.00 0.83 0.25 0.00 0.67 1.00
Operational
HD 0.00 0.00 0.00 0.00 0.00 0.83 0.00 0.49 0.00 0.67 0.83
LA 0.33 0.67 0.67 0.50 0.00 0.17 0.50 0.31 1.00 0.33 0.17
SA 0.67 0.33 0.33 0.50 0.00 0.00 0.50 0.20 0.00 0.00 0.00
Social
AE 0.00 0.00 0.00 0.00 0.75 0.50 0.33 0.50 0.00 0.50 1.00
NS 0.00 0.00 0.00 0.00 0.25 0.50 0.67 0.50 0.00 0.55 0.00
from populated areas may minimize noise complaints. In judgments, an MRSS was used to rank and calculate the
general, these considerations are inexpensive and require judgmentsets[27,54].
minimallaborcomparedwiththeothercriteria.
Finally, incorporating the participation of conflicting 3.4. Case Study. As consequence of rapid urbanization and
stakeholdersminimizestheuncertaintyandriskofreproduc- economic growth the solid waste generation is increased
ing homogenous decisions and enhances the quality of the dramatically in Selangor state. Owing to this increase, the
decisions.Additionally,consistentandreliableresultsmustbe searchforandtheprovisionofanefficientsolidwasteman-
achieved[51,52].Thelandfillsittingfactorsandstakeholders agementmethodhasbecomeanessentialmatter[55].Landfill
arebothpredefinedandgroupedinsets.Stakeholdergroup- is the main solid waste disposal method in Malaysia [4].
ingandinterviewsaretime-savingtoolsthateffectivelygather Figure4(c) shows the map of Selangor including Putrajaya
perceptions and values from the experts [53]. However, to and Kuala Lumpur cities. The restricted area that cannot
ensureanefficientandunbiasedrepresentationoftheexpert be used to construct a landfill is shown in Figure4(b).
10 MathematicalProblemsinEngineering
Table10:Weightedsupermatrix.
Environmental Landuse Operational Social
Grouplabels
SW GW FZ TO CS RA HD LA SA AE NS
Environmental
SW 0.00 0.17 0.24 0.23 0.36 0.13 0.37 0.23 0.16 0.00 0.00
GW 0.31 0.00 0.15 0.00 0.11 0.00 0.00 0.08 0.00 0.00 0.00
FZ 0.12 0.31 0.00 0.11 0.20 0.00 0.00 0.14 0.00 0.00 0.00
TO 0.14 0.19 0.19 0.23 0.00 0.39 0.12 0.04 0.48 0.00 0.00
Landuse
CS 0.04 0.00 0.14 0.00 0.08 0.18 0.02 0.09 0.00 0.18 0.00
RA 0.11 0.00 0.00 0.14 0.15 0.00 0.10 0.03 0.00 0.36 0.54
Operational
HD 0.00 0.00 0.00 0.00 0.00 0.17 0.00 0.14 0.00 0.11 0.14
LA 0.09 0.22 0.19 0.14 0.00 0.03 0.14 0.09 0.36 0.05 0.03
SA 0.19 0.11 0.10 0.14 0.00 0.00 0.14 0.05 0.00 0.00 0.00
Social
AE 0.00 0.00 0.00 0.00 0.08 0.04 0.04 0.06 0.00 0.15 0.30
NS 0.00 0.00 0.00 0.00 0.03 0.04 0.08 0.06 0.00 0.15 0.00
Table11:Limitmatrix.
Environmental Landuse Operational Social
Grouplabels
SW GW FZ TO CS RA HD LA SA AE NS
Environmental
SW 0.173 0.173 0.173 0.173 0.173 0.173 0.173 0.173 0.173 0.173 0.173
GW 0.085 0.085 0.085 0.085 0.085 0.085 0.085 0.085 0.085 0.085 0.085
FZ 0.099 0.099 0.099 0.099 0.099 0.099 0.099 0.099 0.099 0.099 0.099
TO 0.188 0.188 0.188 0.188 0.188 0.188 0.188 0.188 0.188 0.188 0.188
Landuse
CS 0.058 0.058 0.058 0.058 0.058 0.058 0.058 0.058 0.058 0.058 0.058
RA 0.083 0.083 0.083 0.083 0.083 0.083 0.083 0.083 0.083 0.083 0.083
Operational
HD 0.038 0.038 0.038 0.038 0.038 0.038 0.038 0.038 0.038 0.038 0.038
LA 0.135 0.135 0.135 0.135 0.135 0.135 0.135 0.135 0.135 0.135 0.135
SA 0.091 0.091 0.091 0.091 0.091 0.091 0.091 0.091 0.091 0.091 0.091
Social
AE 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029 0.029
NS 0.021 0.021 0.021 0.021 0.021 0.021 0.021 0.021 0.021 0.021 0.021
Therestrictionmapwasobtainedbyimplementingtheguide- sizerequiredforeconomicallyefficientgascollectionsystem
linesissuedbyDepartmentofEnvironment.Theseguidelines and the recommendation for potential impacts of landfill
determinetheprohibitedlandfillconstructionareasthatare basedonitssize[57].Theranksofthepotentiallandfillsites
urban,sensitiveecologicalareas,heritageandculturalsites, are shown in Table7. These ranks were obtained using the
strategicagriculturalarealikepaddyfields,floodplainzones, resultsofMRSS-ANPmodelforsiteevaluationcriteriaand
swamps and water bodies, and parks. Moreover, it suggests Suitability Index (SI), which is the sum of products of the
a buffer distance, like distance from human settlements standardizedscoreofeachcriterionmultipliedbytheweight
(500m), highways (300m), floodplain areas (100m), and ofeachcriterion.ThehighestranksareforsitesnumbersLF4
proximity to surface water (100m buffer). The restriction and LF2, with SI equal to 0.859 and 0.832, respectively, as
arearepresents80%ofthetotalSelangorarea.Thetopmap showninFigure4.
inFigure4(a)showsthepotentialareaingreencolor.After
that,sevensitesweredeterminedasapotentiallandfillsites 4.Conclusions
basedontheirarea.Thelandfillareaassumedtobearound
100hectare,andthisassumptionisbasedonPariatambyand Thesitingofundesirablefacilitiesisaprocesscharacterized
Tanaka (2014) recommendation [56] for minimum landfill by uncertainty and complexity, as well as multiple and