Namibia PDNA 2009 - GFDRR

this coverage is not yet processed into new digital maps, are
individual ortho-photo tiles of 10 by 10 km2 available at the
DMS in digital format (GeoTIFF). Since the ortho-photos were
collected in the dry season, they would have provided the best
possible reference data set for the flood assessment work.
1:250K maps are useful for general orientation and site
location and 1:50K maps and digital ortho-photos in particular
for detailed field verification mission planning and comparison
to satellite image based results. For the field teams, some
40 copies of paper maps at 1:250K and 1:50K scales were
purchased. Unfortunately, DMS was not able to provide the
PDNA team with digital map data at 1:50K and ortho-photo
tiles for the affected towns.
The Statistical Office of the National Planning Commission is
collecting updated GIS data sets in preparation of the 2011
census. Staff at the Census Bureau provided a number of specific
sets that would support the DaLA sector specific analysis.
Shapes files were provided for the following layers: agriculture,
administrative boundaries (constituencies, regions), education,
health, hydrology, planning, population, tourism, transportation
and utilities. Some were specific to the northern regions, but
several are for Namibia as a whole. Several of the layers are
more actual than the equivalent DMS digital data sets. This is
particularly relevant in the North, where significant changes
were registered compared to the 1996 ortho-photo source.
An update of the road network was collected in 2008 and
2009, using GPS surveys.
The National Planning Commission data sets were made
available for exclusive use in the PDNA exercise. Extracts of
the relevant GIS data layers were prepared as KML formatted
files for use by the various sector teams. KML formatted data
can be directly displayed in Google Earth, i.e. not requiring
specific expertise in dedicated GIS software. The figure below
provides an example of NPC data sets integrated into Google
Earth for use in mission planning. Locations of schools (yellow
building symbol) and health clinics (Red Cross symbols) are
displayed with the road network, for an area North of Oshakati
on top of the Google Earth background imagery. The data
sets were used to plan field survey assessments of damage and
losses in the educational and health sector.
Satellite imagery and derived map
products
Satellite imagery provides both geographic location and
spatial representation of features at the Earth’s surface. Shape,
size and visual appearance of those features depends both
on the sensor that was used onboard the satellite and how
the data was processed after reception. The most common
satellite sensors used for situation assessment are electrooptical
sensors, i.e. digital devices that register the reflected
visual and near infrared (VNIR) part of the electromagnetic
Figure 43: An example of NPC data sets integrated into Google Earth
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