ENGINEER- Vol. XXXXI, No. 05, pp. 87-94, 2008© The Institution of Engineers, Sri Lanka

Using GIS for Assessment of Terrorists Attack RiskAlong a Major Road and to Propose Security Options

W. G. Sumathipala and N. T. S. Wijesekera

Abstract: In Colombo and its suburbs, the risks of terrorist attacks are increasing day by day. The riskof civilians coining under attack is greater in areas that are with a greater presence of key decisionmakers. Therefore, in each of such locations the government has an obligation to assess the associatedrisk and then to facilitate with sufficient security to ensure civilian safety at least during the presence ofkey decision makers.

The parliament road from the Colombo Fort passing Kollupitiya and reaching the parliament at SriJayewardenepura can be considered as a major road that faces a significant risk due to the frequentpresence of important decision inakers. Hence it is necessary to identify the risk factors associated withthe parliament road. GIS provides a significant advantage when assessing the risk ratings of anassociated geographic area and then identifying a suitable security system for public safety.

The present work describes the terrorists attack risk status along the parliament road determinedthrough a simple GIS overlay model. The project area covers a road length on 12km. Data used for theGIS model were 1:50,000 maps of roads, GN boundaries, Land use, Population, Previous Incidents,waterways Spatial distribution of risk indicators were overlaid with a conceptual security deployment.The present work has not considered the present deployment along the parliament road due to securityreasons.

The GIS model demonstrates that it can be effectively used to plan and deploy security to ensure thesafety of road users.

Key words: GIS Model, Security, Risk, Road Assessment

1.0 Introduction

Escalation of LTTE terrorist activities has forcedthe government to find ways to ensure thesafety of the public, public representatives andpublic property. The brutal terrorist attacks inthe country have created significantdisturbances to civilian l i fe . Though thecommunities all over the world denounce theattacks on innocent unarmed civilians, thecivilians are the set who suffers and absorbsmost of the damage. Civilian lives are more atrisk when they are among key decision makersand public representatives. In most occasionsthe general public are forced to be with thedecision makers or are forced to attend meetingsof public representatives. As a result suchsituations become unsafe for the public. It is wellunderstood that anywhere in the worldterrorists would attack common types ofinfrastructure and these have been welldocumented. Roads, Key GovernmentEstablishments, Officer Residences and PublicMeetings are some of the common targets [7,

10]. During the history of separatist war, SriLanka has lost many of the leading publicrepresentatives due to terrorist attacks. Theincidents have been either along main roads orat public rallies. When safety of the generalpublic is concerned, locations that encountersthe presence of general public along with KeyDecision makers fall into top priority areacategory where risk assessments should beperformed. As a result, in case of such locations,the government has an obligation to assessassociated risk and facilitate sufficient securityat least during the time periods when keydecision makers are present.

Road coded as ASP which links parliamentcomplex of Sri Lanka to the core of Colombo

W.G Suinatliipala, Geographic Information for Strategic DefenceApplications, Centre for Research & Development, Ministry of PublicAdministration, Defence, Law and Order, Arnn/ Cantonment, Panagoda,Hoinagania, Sri Lanka

Eng. (Prof.) N.T, Solian Wijesekera B.Sc.Eng. Hons.(Sri Lanka),PG.Dip (Moratuwa), M.Eng.(Tokyo),D.Eng. (Tokyo), MICE(UK),FIE(SL), Chartered Civil Engineer, Department of Civil Engineering,University of Moratuwa, Katubcdda, Moratuwa, Sri Lanka.

87 ENGINEER

Municipality area is frequently used by Publicrepresentatives and important GovernmentOfficials. This road links many residential areasto public facilities and commercialestablishments. The parliament of Sri Lanka orthe National State Assembly is the centralmeeting place for Key decision makers of thecountry. His Excellency the President is theleader of the Nation and the Presidentialsecretariat which coordinates the actions of thePresident is linked to the Parliament by thismain Road. As a result, this road is verycommonly used by the Public Representatives,Heads of Departments and Other governmentofficials. This road is the main link for thepersons in Residential Areas of Battaramulla,Kaduwela, Malambe, and Kotte to reachColombo Municipality area where the popularschools, main hospitals, most governmentoffices and vast commercial activities arelocated. This road is an alternative to reachBorella for those who use Kandy Colombo A-lroad. High-level road (A-4) users also deviate atMeepe to join this road to avoid trafficcongestion at Maharagama, Nugegoda etc.Therefore, considering the criticality of aterrorist attack, this road could be considered asa priority location for a risk assessment.

Risk management of this road requires theassessment of many factors which are spatiallydistributed. Hence it involves decision makingbased on map referenced information.Geographic Information Systems are excellenttools for decision making with the use of modelsinvolving several map overlays. [5, 4]

Effective capability to use GIS for such riskassessments would be of immense importancefor the government to provide public security.This has been emphasized in literature [3, 10].Therefore, the present work describes anapplication indicating the potential use of GISfor risk assessment in a spatially distributedmanner using the important parliament (ASP)road as a case study. The work also indicates thepossibility of incorporating the securitystrengths to ensure public safety. Since thepotential of using GIS efficiently will be a veryimportant factor for the assessment of publicsecurity in other areas as well, this study wouldbe an important contribution to public safety.

2.0 Study Area

The study area is a spatial extent ofapproximately 32km2, consisting of 33 GramaNiladari Divisions (GND) in the Colombo andSri Jayewardenepura jurisdictions, fallingwithin 60 521 and 60 571 North Latitudes andwithin 790 501 and 790 561 East Longitudes.Road which is popularly known as theParliament Road reins from Kollupitiya toNational State Assembly of Sri Lanka (located atBattaramulla) and is officially labelled as ASProad (survey 1989).

The study which looked at the security for theaccess from the Colombo city to National StateAssembly (NSA), selected a link road fromColombo Fort to ASP near Kollupitiya and thebalance of ASP as the road for the study (Figure1). The road sections selected for the assessmentcrosses the baseline road at approximately halfway. Total length of road selected for the casestudy is 12 km. The study which targeted toassess the risk status at least to a distance of400m from the road, selected the GramaNiladari Divisions (GND) covering theminimum distance of 400m, as the spatialcoverage for GIS Model. Considering reasons ofadministrative convenience, the full extent ofeach GND was chosen of the study. Land use ofthe study area mainly consisted of Homesteads-17.77 km2 (55. %), Built-up Area - 6.49 km2 (20.%), and Water - 6.73 km2 (21. %). Land coverdistribution details for the study area is in Table-1 Road coverage of the study area consists of12% main roads, 84% minor roads and 4% ofcart or jeep tracks. Table2.

Figure 1 Map of Flo ject Aiea

Figure 1: Map of Project Area

ENGINEER

Table 1: Land use Distribution of Study Area

Description

1 Homestead2 Built-up Area3 Grass Land4 Paddy5 Rubber6 Water & Marsh7 Bay, Sea, Sand

Total

Area(sqkm)

17.776.490.570.580.016.730.06

32.21

Percentage

55.18%20.14%

1.75%1.80%0.05%20.9%0.18%100%

Table 2 : Roads Distribution of Study Area

Description

123

Main roadMinor roadJeep or Cart trackTotal

RoadLength km

41.06290.76

16.41348.24

Percentage

12%84%

4%100%

3.0 Objective

Objective of the work is to demonstrate thepotential of GIS to assess the terrorist attack riskalong a major road which is selected as theparliament road and to incorporate securityoptions in a systematic manner, therebyenabling the effective use of GIS for securityrelated operation.

4.0 Methodology

Risk is a function of assets, threats andvulnerabilities. Risk is described as the potentialfor an unwanted event to occur due to actions ofterrorists. Terrorist threat is the capability andintention of an adversary to undertake actionsthat are detrimental to the government.Vulnerability is any weakness in an asset orcounter measure that can be exploited by aterrorist to cause damage to the government. Inrisk assessment, a criticality of an asset which isan evaluation of the relative importance of anasset within a jurisdiction is the foremost task.A terrorist risk assessment combines criticality,threat and vulnerability and is summarized in toa risk status as given in the following [10].

Risk = Threat x Vulnerability x Criticality

In the present work, the selection of parliamentroad for the study embeds an initial evaluationof criticality which had concluded on thelocation by considering the traffic that isassociated with the road, the concerns with

respect to the, National State Assembly, themovement of public Representatives, the link tocity centre etc.

Similarly on assessment of the threat componentfor the work had also been taken care of byclearly identifying the parliament road as anasset that creates a very high threat to Publicand Public- representatives once the terroristcapabilities, intentions, and tactics are carefullyconsidered. Therefore, for the parliament road,of which the criticality and the threat had beenprioritized, a vulnerability assessment wouldreflect the risk assessment. Such assessmentneed to incorporate the identif ication ofweaknesses in physical structures, protectionsystems, processes or and other areas that maybe exploited by the terrorists. Therefore, theobjective function for the assessment of spatialvariability of terrorist attack risk associated withthe parliament road identified that the keyparameters are the road, link roads, land cover,population distribution, previous incidents,built-up area coverage and number of junctions.Parameter data layers were combined withadministrative boundary data to enableidentification of risk in relation to suchdivisions. A simple qualitative weighted overlayGIS model was developed to assess the risk inthe spatial vicinity of parliament road (Figure-2).

A questionnaire based user survey [9] wascarried out to identify important data layers,same survey incorporated data capture fieldsthat are necessary for the identification of spatialzoning with regards to influencing parameters.Map data collection, checking and computationwere carried out as an initial task of modeldevelopment. Data layers used for the study are

Layei

Figure 2 : GIS Overlay Model used for the Study

89 ENGINEER

Table 3: Data layers used for the study

Data layer

1 Road

2 Junctions3 GND

4 Land use

5 Waterways and Marsh7 Previous Incidents

Description

Main, Miner, Jeep or Cart track,1:50,000 mapMajor junctions from 1:50,000 mapTotal Population as Attributes1:50,0001:50,000 reclassified to groupsaccording to study objectives1:50,000 land use1:50,000 Incidents Map

Layer type

Poly Line

PointPolygon

Polygon

PolygonPoint

Spatial zoning

Buffering of Main and Link roads

Buffering of intersections.Population Density

Land use type to extractWaterways and Built-up area, etc.Buffering of Waterways.Buffer of incidents

Terrorist Risk Assessment

Identify Objective

J_Literature Survey User Survey

Conceptual Model DevelopmentObjective functions Layer Pric-ritEations Layer

arrangement

Map Data Collection aid Ckecking

Layer Preparation

IEGIS Model Development

Model Execution Overlay Opeati

IIdentiiyRiskStatus

Development of Security Options

Yes

Risk Status Map, Statistics, SecurityArrangement/Requirements

Figure 3 : Execution Methodology flow Chart

shown in Table 3. Overall process flow chart ofthe execution methodology is shown in Figure3.

Questionnaire survey which was carried outusing a sample of educated stakeholdersconsisting 29 persons identified the distancespertaining to each feature Layer describingspatial zones with a five class hierarchicalqualitative classification [9]. The distances werethen regrouped using the frequency plots.Ranks and final parameters for the model wereestablished from the use of frequency valuesand a trial and error method to find commonlyunderstood and rounded off values. Parameterscomputed for spatial zoning of each layer are

shown in Table-4. Spatial Zoning Distances(meters) from each feature and correspondinguser Preferences (%) computed from thefrequency analysis of response details capturedfrom the field survey are presented in Table 4 tojustify the selections. Spatial variation ofPopulation density was carried out for eachGrama Niladari Division, by demarcating andcomputing the land area that could be occupiedfor dwelling. The separated Landuse layer wasreclassified as buildable lands and other landuses namely homestead, built-up area,grassland and rubber were taken as buildable.Population density (persons/ha) in each GNDwas calculated. During calculations it wasconsidered that public were living only onbuildable lands and therefore, the un-buildablelands were classified and masked. PopulationDensity maps were classified using naturalbreaks in the frequency curve of computedvalues. The land use layer was reclassified as agroup called Waterways consisting of similarland use classes namely Lakes, Canals,Waterhole, Marsh, Sand and Beach areas.Polygons of waterways class which wasconsidered as non buildable area was assignedwith zero population (Table-5).

Total buildable area of the project area wasapproximates 79%. Areas from Waterwayfeatures were demarcated as per userpreferences to develop the spatial zoning of riskdue to waterways. Threat due to built-up natureof properties was developed using the land uselayer. Non buildable lands were masked and therest were classified as in the Table 5. To map riskzones based on land use type other data layerswere classified according to spatial zonesindicated in Table-5. The GIS model used aqualitative assessment of spatial distributions ineach selected layer to carry out a layeraggregation through a spatial overlay

ENGINEER 90

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Table 9: Security Deployment for ProposeManagement Option

Figure 4: Overall Risk Status Indicatorsfor the Study Area

Table 8: Risk Status Indicator and Spatial Extents

Risk Status Indicator

VHHMLVLNoTotal

Area (Ha)

113.40215.86320.401002.83953.96614.993221.44

Security deployments were carried outmanually with initial placement of groupedsentry to cover High and Very High risk regionsand then single person stationary sentries wereplaced to fill gaps which were spatiallydistributed. Four mobile patrol cars were placedalong the parliament road to support thesecurity of surrounding vicinity along byroads.The security mobilization in the area is shown inTable-9. A Management Option which proposeda trial security arrangement was developed asthree GIS layers having spatially varyingsecurity zoning. The three layers were givenequal weights and were overlaid to combine asthe overall security indicator layer. The overallsecurity indicator layer was then reclassified tothree qualitative security indicator groups asVery High, High, and Moderate, the aforesaidsecurity status Indicator for The mentionedmanagement option is shown in Figure 5.

Proposed Security Indicator Layer was thenoverlaid with the Overall Risk Status Indicatorlayer to assess the spatial distribution of thesecured status for the proposed securitydeployment. The results from overlay operationwas classified to a three class "secure" statusclasses as Secure, Moderately secure, and

Type of Security

1 Group Sentry2 Stationary Sentry3 Mobile Patrol

No of Units

20138704

Figure 5 : Arrangement of Secuity andSpatial Distribution of overall security indicator

for the study area

Figure 6 : Security Status Distributionafter Security Mobilization

Highly secure. Figure 6 shows the spatialvariation and Table 10 indicates the spatialcoverage by each zone.

The spatial matching of risk status indicator andthe security status layer through an overlayoperation was based on a simple matrixassessment which classified the 5 class risk statusindicators to arrive at the new classification ofsecure status with three classes (Table 11)

Overall Risk Status indicator and the securestatus indicators after the management optionwere spatially aggregated to Grama NiladhariDivisions and the results are shown in Figure 7

ENGINEER 92

Table 10 Spatial Coverage of Secure Regions inProject Area.

Secure status Indicator

Highly SecureModerately SecureSecure

Spatial extent (Ha)

810.172294.09117.19

Table 11: Risk and Security Status Indicator SpatialOverlay and reclassification

Tabl«11: K-A and Security Status sfetor Spatial

Figure 7: Overall Risks status arranged toGN Division boundary

and Figure 8. The indicators were classified- asfive and three qualitative groups according toNatural breaks in the frequencies ofoccurrences. This spatial aggregation enablesmanagers to identify status of the area and thento mobilize resources accordingly.

6.0 Discussion

The case study showed systematic analyses ofthe risk status and the incorporation of security

Figure 8: Aggregate Secure Status Indicator forGN Divisions

using GIS as a tool. The simple conceptual GISmodel used in the study enabled thecomputation of status indicators to visualize thepattern of variations in space. The model showsstrength of GIS to carryout easy incorporation ofvarious spatially distributed managementoptions with relative ease.

The sample size used for the user surveys wereonly 29. This sample of 29 for an approximatepopulation of 600,000 at 95% confidence limitprovides a confidence interval of approximately20%. Therefore, for detailed applications it maybe necessary to perform calculations with largersamples. [1, 2]

Spatial zoning different data layers aresubjective. The study used a surveyquestionnaire to identify spatial zoningpreferred by various stakeholders and thenincorporated statistical indicators to arrive atsuitable distance ranges for geographicdistributions. Spatial zoning of securityIndicators was carried out with judgmentalvalues and these needs to be carefullyascertained and strengthened for actualapplications. Incase of actual applications, thesystematic approach of this study may beadopted with parameter strengthening throughwider user community surveys.

Statistics derived from the spatial analysisindicates the potential and value of aggregatingthe GIS results for management of resources orplanning of similar activities. Results wouldenable the mobilizations either on the basis ofsmaller land parcels based on uniform statusranks or on the basis of administrative divisions

93 ENGINEER

T

which have spatially averaged status rankings.The casestudy applications indicated themethodology of applying CIS concepts tovarious points, line or polygon data sets,carrying out of spatial zoning an overlayoperation, thereby presenting an example ofsystematic procedure for similar GISundertakings. The casestudy also indicates thepotential of GIS to easily incorporate conceptchanges through a change of data layers orchange of spatial data arrangements. In case amanager requires to modify a securityarrangement then it is necessary to incorporatethe change to the respective security data layer,overlay with other security data layers and thenfinally combine with the risk status indicator tomake an assessment to identify the adequacy ofproposal. On the other hand, if the modificationsuggested is not final, then a separate layercould be added only for the change and thenoverlaid with the available final to identifywhether the change had provided the desiredresult. A manger can use either of the optionsbased on a given situation. Such manipulationcapabilities will add to the strengths of aresource manager.

Spatial aggregation capability of GIS enables amanager to compute weighted averages basedon the effected spatial extents. This is a veryeffective tool in GIS for rational management ofresources.

7.0 Conclusions

1.0 The potential of GIS for risk and securityassessment of spatial extents which are atclose proximity to important infrastructurewas successfully showed through a case -study application.

2.0 The study presented a systematicmethodology to use a simple GIS modelwith appropriate stakeholder input forparameter strengthening.

3.0 Results of the case study application showedthe pattern of risk and security options thatare much needed by resource planners andmanagers.

4.0 Effectiveness of spatial aggregation in GISby the incorporation of weights based oninfluence area was shown through the case -study.

5.0 The model used for the present work can beeasily used as effective tool for similarstudies.

8.0 Acknowledgments

The authors wish to extend sincere appreciationof the encouragement given by the managementand the staff of Ministry of Defence, and theCentre for Research and Development topublish this work. Support of the ICGAT ofUniversity of Moratuwa and its s taff isgratefully acknowledged.

9.0 References

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6.0 Malczewski, }., GIS and Multicriteria DecisionAnalysis, Department of Geography, Universityof Western Ontario, 1999,pp 177 -189.

7.0 OSHA- Occupational Safety & HealthAdministration, "Emergency Preparedness-Fireand Explosion Planning Matrix", 200,Constitution Avenue, NW, Washington DC20210, 2008, http://www.osha.gov/dep/five-expma trix/ index.

8.0 Risk Management: An Essential Guide toProtecting Critical Assets www.iwar.org.uk/comsec/resources/risk/ risk-mgmt.pdf, Visted,1st January 2008

9.0 Tan, W., Practical Research Methods, 2nd Ed.,Prince Hall, 2004

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