APPLICATIONS OF SPACE IMAGERY IN THE DEVELOPING COUNTRIES
Dan Rosenholm
Department of Geodesy and Photogrammetry
Royal Institute of Technology
100 44 Stockholm, Sweden
ISPRS commsion - WG IV/2 - International Mapping from Space
KEY WORDS: Land Use Mapping, Natural Resources Inventory, Topographic Mapping, Satellite Images, Developing Countries,
ABSTRACT
The paper describes a number of mapping projects based on satellite images that the Swedish Space Corporation and its subsidiary SSC
Satellitbild have been involved in since 1987. The first large vegetation mapping project, considered a major breakthrough in the earth
observation business, was a land use mapping of the Philippines finalised within one year. A land use mapping, followed by a forest
suitability study on South Sumatra, Indonesia, was carried out in the early 1990’s. During 1992 and 1993 a land use, forestry and biomass
mapping of Malawi was carried out. A forestry mapping project of Northern Namibia started in late 1992 and is beeing finalised now.
In Ethiopia SPOT panchromatic stereo images were used to derive a DEM, contour lines with 20 metre intervals and orthophotos for
mapping at 1:50,000. Twenty-seven 1:50,000 topographic map sheets of the islands of Cebu and Bohol in the Philippines were produced
based on existing old topographic maps and SPOT images. As a part of the National Population Census of Nigeria, 177 planimetric maps at
1:50,000 were produced in early 1990. This mapping led to an updating of the regular 1:50,000 series by the Federal Survey Department of
Nigeria of 350 more map sheets. In the Baltic States ongoing projects are producing a new series of topographic maps based on
orthocorrected SPOT Satellite Image Maps.
Earth Observation technology is a fully operational tool for land use and vegetation mapping and revision of topographic maps in developing
countries. Major issues are related to availability, where cloudiness is one major problem and the programming and distribution system
another. Strict handling of geometrical problems is essential in all applications. The trade-off between spectral, spatial and temporal
resolution is treated. A typical land cover project design is described. Conclusions are made.
1 INTRODUCTION
The Swedish Space Corporation (SSC) and its subsidiary SSC
Satellitbild have since 1987 been involved in a number of
mapping projects in developing countries using satellite data.
The first large vegetation mapping project, considered a major
breakthrough in the earth observation business, was a land use
mapping of the Philippines finalised within one year. The
project was carried out at a time when remote sensing was seen
more as a tool for researchers, using scenes or parts of scenes,
than for practical use in larger areas. Since then thematic
mapping and topographic mapping projects have been carried
out by SSC on all continents.
2 PURPOSE
The purpose of this paper is to share the experiences from
SSC’s international mapping projects and point out the
important issues in mapping from space in developing
countries.
3 PROJECT DESCRIPTIONS
3.1 Land Cover Mapping of the Philippines
During one year’s execution time, between 1987 and 1988, a
full Land Cover Mapping at 1:250,000 of the Philippines was
carried out using SPOT scenes (Rasch et al, 1988, Rasch,
1994). The primary goal of the project was to establish land
cover statistics for project planning at the World Bank. The
choice of SPOT was primarily based on the programming and
tape recorder capabilities in combination with the flexibility and
repeatability due to the side-viewing capabilities. In the
beginning of the project almost no useful images existed and at
that time it was practically more or less impossible to get a
coverage with Landsat. A sufficiently cloud-free coverage was
achieved during the project period, partly due to the fact that
there were more cloud-free periods than usual during the year.
The mapping was performed by interpretation of precision
corrected scenes at a scale of 1:100,000. 24 land cover classes
were interpreted on the 187 scenes used, 43 map sheets at
1:250,000 were produced and land use statistics by region were
computed. To obtain ground truth and give the interpreters an
understanding of the area 19 air reconnaissance and 7 ground
surveys were carried out.
Twelve months was, especially in 1987-1988. a short time for a
project of this size. It was possible due to the characteristics of
the SPOT system and the enthusiasm of the team. The accuracy
of the classification was good - the only frequent problem was
two forest classes that were mixed up - especially taking into
account that the number of actual classes was twice as much as
stipulated by the contract. The project has since then got many
followers internationally.
3.2 Forest Suitability Mapping on South Sumatra
As part of a study on management plans for industrial forest
plantations of parts of the Musi River watershed, South
Sumatra, two sequential studies of the same area were carried
out jointly by SSC Satellitbild and Swedforest International.
This is a part of Indonesia with intensive land use and rapid
changes. A land use mapping in 20 classes was followed by a
forest suitability mapping based on the land use information.
Forest Suitability Maps are powerful instruments for land use
planning and decision makers (Fig. 1). Satellite Image Maps of
multispectral SPOT Images, complemented with Landsat TM
scenes were used. The initial study was of pilot character and
was carried out on twelve map sheets at a scale of 1:50,000. The
project was carried out jointly by SSC and Swedforest
International and was finalised in 1991. Sumatra is, like most of
Indonesia, extremely cloud covered. The areas were selected at
that time based on existing satellite data.
The results were considered very satisfactory and have led to an
ongoing full scale project covering 109 1:50,000 map sheets on
East Kalimantan (Borneo) and Sumatra.
704
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
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