Garmin GPS Manual page 9

09/25/02
CHAPTER 2: WHY USING GPS IN THE CONTEXT OF
THE WHO WHS ?
The first reason for using GPS in the WHS context is the added value it gives to the
survey by allowing the geographical dimension to be taken into account without
requiring important investment (many GPS receivers are inexpensive, GPS data is free,
and survey staff can be trained quickly to their use).
By knowing the geographic location of each cluster it will be, for example, easier to go
back to the same place for supplementary data collection.
With the geographic location it is also possible to use the information collected by the
receiver within the Geographic Information Systems (GIS). A GIS can be defined as
being a computer system for capturing, storing, checking, integrating, manipulating,
analysing and displaying data related to a position on a surface (AGI dictionary).
By integrating the location of the WHS clusters into a GIS it will firstly be possible :
- to examine the relationship that may exists between the data collected and the
infrastructure located within or around the clusters. This concerns, for example,
health facilities, roads, market, water pumps and so on. If the location of these is
known, the GIS tool will be used to calculate the distance to the nearest
infrastructure and include this information into the survey analysis.
- to extract figures at the cluster level from other spatially distributed information
such as Digital Elevation Models (altitude), environmental parameters (climates,
landuse,...) and use them in multivariable analysis.
- to aggregate the clusters according to new units of analysis, such as climatic
zones or ethnic regions.
- to extrapolate some of the figures collected by the survey using other
geographically distributed parameters which include modelling capabilities.
With all this information being implemented in the GIS tool it will then be possible to
have a first picture of the distribution of the poor. Knowing where they are located could
then be used to know if this distribution is related to the distribution of other parameter
(health, education,...).
The use of GIS will also help in the creation of thematic maps that will be used in
presentations and/or reports.
Finally, GIS could be used in the future in order to help designing the sampling frames
and the GPS used to find the location of the selected clusters.
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