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Extracting Parcel Boundaries from Satellite Imagery

for a Land Information System

Zahir Ali

ManagerPakistan Space and Upper Atmosphere Research

Commission (SUPARCO), PO Box 8402

Karachi, Pakistanseezahir@yahoo.com

Shafiq Ahmed

Director General

Pakistan Space and Upper Atmosphere Research

Commission (SUPARCO), PO Box 8402

Karachi, Pakistan

shafiqah@gmail.com

Abstract Land Information System (LIS) primarily depends on

the availability of reliable spatial and non-spatial datasets.

Currently, the cadastral maps in Pakistan are mainly in paper

format lacking cartographic standards. Therefore, these maps

cannot be used directly as an input to the LIS. Such a situation

demands that all cadastral information in these traditional maps

be timely maintained in standard forms with quality indicators asinformation for the users. Considering the present situation in

Pakistan, this paper firstly elaborates the present cadastral

mapping system and the methods used for producing, updating,

and maintaining these cadastral data. This research paper

investigates on the use of satellite imagery in timely maintaining

of parcels boundaries and cadastral mapping in LIS. The abilities

of remote sensing imageries in parcel boundaries extraction and

cadastral mapping are assessed using QuickBird high-resolution

satellite images for two case study areas in the Khyber

Pakhtunkhwa province of Pakistan. This study introduces the use

of QuickBird panchromatic and colour imageries to develop a

method for cadastral surveying through on-screen digitisation

techniques. This study shows that the cost and time can be

reduced to its half if the cadastral maps are generated using the

newly developed technique.

Keywords- Cadastral Mapping, LIS, Image Processing, QuickBird,

Satellite Imagery

I. INTRODUCTIONUpdating land related information is very important so that

changes of ownership and division of property can be recordedin a timely fashioned manner for documentation. The use ofremote sensing (RS) images can play an important role forupdating and extracting land related information. Oneadvantage of using RS images is that they provide a historicalrecord of the areas that can be revisited in the future to see

what changes have taken place. In this way old images canprovide valuable evidence where conflicts occur in parcelboundaries [1]. Furthermore, traditional land surveyingapproaches are time consuming and require lot of efforts.Sometimes it is very difficult to do cadastral survey in remoteareas especially in mountainous areas when the weather is veryharsh. In this case RS images can be used as an alternative totraditional land surveying approach for spatial data acquisitionwhere most measurements can be done in the office [2].

Due to rapid development in the space born technologynowadays it is possible to generate thematic maps on various

scales keeping in mind end users requirements. The locationalaccuracy of maps is utmost important for certain applicationslike cadastral survey, infrastructure/utility maps, urban landuse, land planning and land consolidation works etc. Cay et al.[3] showed that using one-meter resolution imagery and GPScontrols, it is possible to achieve an accuracy of +/- 2 meters.

Recent advances in space-based data capturing techniques(imaging) have revolutionized the field of cadastral surveyingand mapping. All these improvements in satellite imaging haveled to availability of better quality data/pictures for mappingapplications [4]. Mamoru et al. [5] considered the possibility ofIKONOS imagery for making topo-cadastral maps and theirresults suggested that IKONOS imagery has advantageouscharacteristics of interpretation for making and updatingmiddle-scale topographical maps such as 1:25,000 comparedwith analogue aerial photo. They showed that horizontalaccuracy of IKONOS ortho-imagery varies between 1.0-1.2min flat areas and is worse in mountainous areas.

Land Information System (LIS) primarily depends upon the

available spatial and non-spatial datasets. In case of Pakistan,the available cadastral maps with land administration authoritydo not comply with the barest minimum standards for beingused directly as an input to LIS [6]. Such a situation demandsthat all these traditional maps to be updated and revised to astandard format in which the existing maps can serve as inputin the process of updating or revision.

Keeping in mind the importance of RS imagery, this studyincludes an assessment of QuickBird RS imagery as an input toland information system (LIS). This study focuses on theusefulness of RS imagery for parcel boundary surveying anddelineation to improve quality of existing cadastral maps withland administration agency. This study also highlights the

usefulness of RS imagery in cost & time estimation forcadastral surveying and mapping. The potential use of GarmineTrex GPS navigation receiver and ortho-rectified coloured

pan-sharpened QuickBird RS imagery having 0.6m resolutionis assessed in this study for extracting parcel boundaries.

II. METHODOLOGY, STUDY AREA AND DATA USEDA. Methodology

The workflow to be used in this research work forextracting parcel boundaries from RS imagery is shown inFigure 1.

79978-1-4673-6396-9/13/$31.00 2013 IEEE

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Figure 1. Workflow for extracting parcel boundaries from RS imagery

B. Study Area and Data UsedTwo study areas namely Zormandi and Shalmani in

Peshawar and Swabi districts were selected for this study toextract parcel boundaries from RS imagery. These two areaswere selected due to their distinct geographical features as theZormandi is a flat terrain while the Shalmani is a mountainousterrain. Location of these areas on the provincial map is shownin Figures 2. Zormandi is a flat and plain area with some urbanareas where some part of the area is built-up and very denseand frequent distribution of parcels is available. Shalmani is amountainous rural area where most of the area is open andmostly covered with some forest. The parcel distribution is

infrequent and not very dense.

Figure 2. Location of study areas

QuickBird panchromatic images of 0.6m and colouredimages of 2.4m resolution were acquired for both study areas.A SPOT5 stereopair with 2.5m resolution was also acquired forthe Shalmani area to extract digital elevation model (DEM)information. The DEM was used in ortho-rectification of theShalmani area. Due to flat nature of the Zormandi area, noDEM was used.

Two types of data were integrated in this study; namely theQuickBird ortho-images and field data including groundcontrol points (GCPs). Pre-processing techniques were carriedout with QuickBird ortho-images to assess usefulness ofremote sensing data for extracting parcel boundaries. Fieldvisits were carried out in consultation with BOR officials andland owners to locate and draw cadastral boundaries using fielddata and photogrammetric techniques. Ground surveys were

also carried out for collecting GCPs using hand held GPS(Garmin eTrex navigation receiver) for ortho-rectifying thesehigh-resolution satellite images.

III. EXTRACTING PARCEL BOUNDARIESThe parcel boundaries in flat area were easily identified on

enhanced ortho-rectified RS imagery. In this case, the parcelboundaries were trees, open area or presence of vegetation,roads or foot paths and water drainage with the presence of lowheight vegetation. The boundaries were digitized on ortho-rectified RS imagery through consultation with Patwari (landagency personal for keeping and preparing land records) andland owners in the field. In this case, field visits were carriedout along with map prints of RS imagery and land owners wereasked to find out their parcels boundary. The parcel

boundaries were then digitized using on-screen digitizingtechniques through laptop after confirmation from the landowners and Patwari in their presence. These parcel boundarieswere digitized through ArcGIS v9.3 software. The parcel

boundaries drawn in the flat area are shown in Figure 3.

Figure 3. Digitised parcel boundaries in flat area

Due to flat nature of the study area, it was not so difficult toidentify respective cadastral boundaries on RS imagery.Moreover, the existence of trees on parcel boundaries also

helped to identify parcel boundaries easily and the field sizeswere also according to the resolution of acquired imagery.

Similarly, the parcel boundaries in Shalmani area wereextracted from ortho-rectified RS imagery with the help ofPatwari and land owners in the field. In this case, field visitswere carried out along with map prints of RS imagery and landowners were asked to find out their parcels on imagery. The

parcel boundaries were then digitized using on-screendigitizing techniques through laptop in the field and wereconfirmed from land owners and Patwari in their presence. The

parcel boundaries were digitized using ArcGIS v9.3 software.

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The parcel boundaries extracted in the hilly area are shown inFigure 4.

Figure 4. Digitised parcel boundaries in hilly area

This area was mountainous in nature and it was not so easyto identify parcel boundaries on RS imagery. The field shapeswere not regular and field sizes were very small to identify on

RS imagery easily. Moreover, the RS data quality was not sogood due to mountainous terrain and irregular scattering thataffect quality of the data during acquisition. The shadow effectwas also observed on imagery in some parts of the study areacreating problem in identifying boundaries efficiently.

IV. CONCLUSIONSThis study introduces the use of QuickBird panchromatic

/colour imageries and Garmin eTrex GPS navigation receiverto develop a method for cadastral surveying through on-screendigitization techniques in the field. In this study, the QuickBirdimagery and GPS navigation receiver were used for extracting

parcel boundaries in consultation with the stakeholdersincluding land owners and land administration authorities. Inthis study, the Garmin eTrex GPS navigation receiver was usedfor collecting ground control points and SPOT5 stereopair wasused for generating DEM which were then used in the processof ortho-rectification. Using RS imagery, more parcels can besurveyed in a less time as compared to the old fashioned parcel

boundaries delineation method.

ACKNOWLEDGMENT

We acknowledge Mr. Nouman Shah Jadoon (MBR), Mr.Kifayatullah Khan (DLR), Mr. Ajmal Bhatti (SO) of the Boardof Revenue for their guidance and assistance with datacollection. We also thank Pakistan Space & Upper AtmosphereResearch Commission (SUPARCO), International Institute forGeo-Information Science and Earth Observation (ITC), the

Netherlands, Higher Education Commission (HEC) of Pakistan

and the Netherlands Organization for International Cooperationin Higher Education (NUFFIC) for providing this researchopportunity and funding assistance.

REFERENCES

[1] P. F. Dale and J. McLaughlin, Land Administration.

Oxford: Oxford University Press, 1999.

[2] A. M. Tuladhar, "Innovative use of remote sensing

images for pro poor land management," presented at

the Secure land tenure : new legal frameworks andtools in Asia and the Pacific, Bangkok, Thailand,

2005.

[3] T. Cay, O. Corumluoglu, and F. Iscan, "A Study on

Productivity of Satellite Images in the Planning Phaseof Land Consolidation Projects," presented at the

XXth ISPRS Congress "Geo-Imagery BridgingContinents", Istanbul, Turkey, 2004.

[4] Ajai, "Mapping for Micro-Level Planning: The Issues

& Challenges,"Indian Cartographer, vol. 22, 2002.

[5] K. Mamoru, K. Toshihiro, W. Nobuyuki, and M. J.

Kaoru, "Interpretation Characteristics of IKONOS

Imagery and its Coordinate Accuracy Validation,"Journal of the Geographical Survey Institute, vol. 94,

pp. pp. 38-47, 2002.

[6] Z. Ali and M. Shakir, "Implementing GIS-based

Cadastral and Land Information System in Pakistan,"

Journal of Settlements and Spatial Planning, vol. 3,

pp. pp. 43-49, 2012.

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