International Archives of Photogrammetry and Remote Sensing. Voi. XXXII Part 7C2, UNISPACE III, Vienna. 1999
13
I5PR5
UNISPACE III - ISPRS Workshop on
“Resource Mapping from Space”
9:00 am -12:00 pm, 22 July 1999, VIC Room B
Vienna, Austria
I5PR5
the poorly developed countries with 2.7 % per year and that it these countries (see figure 1).
goes hand in hand with urbanization of up to 5 % per year in
Figure 1: Population Statistics and Predictions
The urban population is at present about 45 % of the total. 80 %
of the world population is expected to be urban bv the year
2025.
Most of the highest urban growth rates are expected to be in
Asian cities, such as Dhakar (7.8 M) 5.7 %, Jakarta (11.5 M) 4.4
%, Karachi (9.9 M) 4.3 %, Mumbai (15.0 M) 4.2 %, Shanghai
(15.1 M) 2.3 %, and Bangkok (7.1 M) 2.2 %.
3. The Need for Basic Data Sets in Geographic Information
Systems
In the last 20 years geographic information systems have been
developed as computer systems capable of input, storage,
manipulation, analysis, and output of geographic data.
In its wider definition a GIS is, however, a data system of
managing the environment for sustainable development for
* analysis of data for gaining information
* for planning with information
■ for decision making and
■ for implementation and monitoring of decisions.
It is to be realized that hard and software of a GIS rarely
exceeds 20 % of its cost. The data are the most expensive part
with 80 %. Thus a data system needs to be kept up to date.
A GIS due to its data integration capability from various sources
has the advantage of being at least 4 times more cost-effective
than the simple computer automation of a task.
4. The Need to Provide Timely Base Data Sets at Various
Scales
A survey of data acquisition costs for various purposes shows a
scale dependence. The larger the scale, the costlier. Costs of less
titan 100 $/km" can only be achieved with satellite imagery.
Aerial or ground survey tools, which can supplement such
surveys, are in general at least 10 times costlier per km 2 (see
figure 2).
