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. 2004 Sep 28;3(1):20.
doi: 10.1186/1476-072X-3-20.

Use of satellite imagery in constructing a household GIS database for health studies in Karachi, Pakistan

Mohammad Ali  1 , Shahid Rasool, Jin-Kyung Park, Shamoon Saeed, Rion Leon Ochiai, Qamaruddin Nizami, Camilo J Acosta, Zulfiqar Bhutta
Affiliations

Use of satellite imagery in constructing a household GIS database for health studies in Karachi, Pakistan

Mohammad Ali et al. Int J Health Geogr. .

Abstract

BACKGROUND: Household-level geographic information systems (GIS) database are usually constructed using the geographic positioning system (GPS). In some research settings, GPS receivers may fail to capture accurate readings due to structural barriers such as tall buildings. We faced this problem when constructing a household GIS database for research sites in Karachi, Pakistan because the sites are comprised of congested groups of multi-storied building and narrow lanes. In order to overcome this problem, we used high resolution satellite imagery (IKONOS) to extract relevant geographic information. RESULTS: The use of IKONOS satellite imagery allowed us to construct an accurate household GIS database, which included the size and orientation of the houses. The GIS database was then merged with health data, and spatial analysis of health was possible. CONCLUSIONS: The methodological issues introduced in this paper provide solutions to the technical barriers in constructing household GIS database in a heavily populated urban setting.

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Figures

Figure 1
Figure 1
The study sites in Karachi, Pakistan. The geographic position of the four study sites along with other geographic characteristics of Karachi are shown in the map.
Figure 2
Figure 2
IKONOS image of Sultanabad, Karachi, Pakistan. The landscape of the Sultanabad study area obtained from IKONOS satellite imagery.
Figure 3
Figure 3
House parcels added to the satellite image, Sultanabad, Karachi, Pakistan. The house parcels drawn using AutoCAD superimposed on to the IKONOS satellite imagery.
Figure 4
Figure 4
The address ID is used to link house parcels to population database, Sultanabad, Karachi. The unique census ID (address ID) of the household assigned to each parcel is shown inside the house parcel (the map in right side). The ID is used to link household census and disease surveillance data.
Figure 5
Figure 5
Entity relationship of the health study GIS database, Karachi, Pakistan. Inter-relationship between spatial and non-spatial database and intra-relationship of the database tables are shown here for the GIS-based health study research project. The descriptions of the entity relationship are descried in the texts.
See this image and copyright information in PMC

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