3.2
Thematic sapping frna small format aerial photography and photo aosaics for the IUIDP,
Indonesia
As in many developing countries,
up-to-date maps (and much other relevant
planning data) are frequently unavailable in
Indonesia. Often the 'best' map is a
topographic map (scale 1:50000) made in the
1930's.
A World Bank sponsored project aims at
detailed (scale 1:1000) mapping of 255 cities.
These maps are based on aerial photos (scale
1:5500) flown in 1983-85 (first series of 100
cities) or after 1988 (second series of 155
cities). At the moment of publication these
maps may be showing the situation of 4 or 5
years ago. For towns with a population growth
rate of 4 % or more per annum, it results in
a considerable part of the urban area on the
map being outdated.
The usefulness of such 'old' maps (if they
are not updated) for IUIDP planning purposes
becomes rather questionable. For instance, a
main item is a reliable calculation of the
number of people within the urban area to be
served by a water purification plant. In the
case of a substantial underestimate of the
population in the catchment area, inadequate
facilities will be provided. If, on the other
hand, guesswork or inappropiate calculation
leads to serious overestimation, the financial
burden to the community will become much too
high. This is not an unlikely situation as
population (census) figures are based not on
the contiguous urban area, but on
administrative areas (kabupaten or desah).
For an economically feasible operation, a
minimum population density is generally
required for infrastructure provision. The
present and expected population density,
therefore, is a key item in the data
collection and analysis that lead to plans and
proposals (Pollé & Hofstee, 1986).
In the absence of adequate, up-to-date
maps and aerial photographs, a creative and
appropiate solution was designed: new small
format aerial photography and mapping,
especially configured for the IUIDP planning
purposes.
At the ITB, the Institute of Technology
Bandung, the Center for Environmental Studies
had initiated its own low-cost aerial
photography operations in 1975 (Poerbo &
Shubert, 1978). This provided a basis for
further development. Technical support by the
ITC upgraded the operations to a level
adequate for the IUIDP requirements. Both
staff training and essential equipment were
provided. The operations, however, are not
really production oriented, but must be
restricted to a non-commercial 'research &
development' activity.
The infrastructure essentially consists
of: a crew for aerial photography, a platform
(a light single-engine airplane with a
facility for vertical aerial photography), a
small format camera (Rollei SLX/6002, image
format 56x56 mm) and mount,and accessories
(overlap regulator, navigation sight).
Eight towns were covered (negative scale
1:20000) in the first half of 1987. From the
enlargements in color (scale 1:5000),
uncontrolled mosaics were made. These mosaics
formed the basis of the initial line drawings
(approximate maps with only roads, railways,
and rivers) and the thematic (land use) maps.
A closely linked operation was started to
train local planning department staff in the
use of air photos and mosaics, and in thematic
mapping and field surveying. From town
planning departments (district and provincial
level) staff was appointed to attend short
intensive training courses.
Additional to the training, the main
output of the workshops was a number of
thematic maps. These maps, based on the recent
air photos and limited field surveys, showed
the land use of the respective towns. Included
were residential densities, commercial and
institutional areas, vacant and agricultural
land, roads, etc. An important element was
that the trainees worked on their own areas,
i.e. an optimal use could be made of their
local knowledge (a very important element in
the interpretation of aerial photographs).
Linked with the land use maps, other thematic
maps are also made for the IUIDP planning
process: population densities (Fig.l), present
infrastructure (water supply, drainage,
sewerage, road networks, etc), quality of
infrastructure (level of service and
aggregated level of service), and investment
program (planned improvements for the next 5
years) . All these maps are made on a common
basis: the initial line drawing ('base map’).
Standardization of the format and contents of
the maps is aimed at, and can be achieved
partially through the training program.
A few facts will illustrate the potential
of the approach applied in the pilot project
phase, which is concentrating on the province
West Java. Photo prints, mosaics, and initial
line drawings (made by the ITB) could be
provided well within 2 months after selecting
the areas. However, weather conditions
(monsoon period) could extend the waiting
time. Security clearances could be obtained
easily at the provincial level, mainly due to
the low-key approach and access to informal
networks. Two towns could not be covered
because of proximity to a major airport with
heavy air traffic (no air traffic control
clearance for the required flying height of
1000 m).
An average town, area 20 km 2 , was covered
within one day, unless a long ferry flight was
needed to reach the target area from the home
base. The average cost charged was about US $
1400 per town (US $ 0,70 per hectare),
including airplane and crew cost, photo
materials, mosaics, and initial line drawings
('base maps'). The subsequent production of a
land use map by trained local staff could be
accomplished within one manmonth.
The provision of the very recent small
format aerial photographs, as discussed here
for the Indonesian IUIDP planning approach,
creates a substantial advantage in terms of
timeliness and trustworthiness of urban
planning data.
Unfortunately, outside West Java no small
format aerial coverage could be realized, due
to security constraints (a fact that was
initially not expected, but established while
the project was already under way).
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