POTENTIAL AND LIMITATIONS OF SATELLITE REMOTE SENSING FOR
GEO-DISASTER REDUCTION
Kees van Westen and Robert Soeters
International Instute for Aerospace Survey and Earth Sciences (ITC), Enschede, NL
Manfred F. Buchroithner
Institute for Cartography, Dresden University of Technology, Germany
KEYWORDS: Remote Sensing, Land Slides, Earthquakes, Volcanoes, Landsat, SAR
ABSTRACT
A disaster is defined as "a sudden calamitous event bringing great damage, loss or destruction". Such events can be
earthquakes, landslides, floods, hurricanes, volcanic eruptions etc. To reduce the impacts of natural disasters a com-
plete strategy for disaster management is required, involving the aspects of disaster prevention (hazard, vulnerability
and risk analysis applied to planning), disaster preparedness (warning and monitoring of disasters) and disaster relief
operations. This paper is concentrating on geology-related natural disasters: earthquakes, volcanic eruptions, and
landslides. For each of these types an evaluation is given of the usefulness of satellite remote sensing in the three pha-
ses of disaster management.
1. INTRODUCTION
A disaster is defined as "a calamitous event bringing
great damage, loss or destruction" [3]. Such events can
be earthquakes, landslides, floods, hurricanes, volcanic
eruptions etc. Some disasters strike within a short period
with devastating outcomes (like earthquakes), whilst
others have a slow onset period with equally or even
more serious repercussions (such as drought). Disasters
can be classified in several ways. One possible subdivisi-
on is:
- Natural disasters are events which are caused by
natural phenomena (such as earthquakes, volcanic
eruptions, droughts, hurricanes)
- Human-made disasters are events which are caused
by human activities (such as atmospheric pollution,
industrial chemical accidents, major armed conflicts,
nuclear accidents, oil spills, desertification).
Another subdivision is into geological disasters
(earthquakes, volcanic eruptions, landslides, etc.)and
ecological disasters (drought, desertification, deforestati-
on, etc.). Almost all disasters are accompanied by a loss
of some kind. This could be in the form of property, infra-
structure or human life. The losses experienced vary with
the type of disaster, its magnitude and the areas affected.
Globally, it appears that the toll of death and damage in
natural disasters is increasing, although there is no inter-
national databank of sufficient comprehensiveness to
verify this supposition. The cost to the global economy
now exceeds US $50.000 million per year, a third of
which represents the cost of predicting, preventing and
mitigating disasters and the other two thirds represent the
direct cost of the damage [1]. Death tolls vary from year
to year around a global mean of about 250.000, while
major disasters kill an average of 140.000 people per
year. There seems to be an inverse relationship between
the level of development and loss of human lives in the
case of a disaster. About 95 percent of the deaths occur
in the Third World, where more than 4.200 million people
live. Economic losses attributable to natural hazards in
developing countries may represent as much as 1096 of a
gross national product. In industrialised countries, where
warning-systems and buildings codes are more sophisti-
cated, it is easier to predict the occurrence of natural
39
phenomena, and to warn people in time. The damages,
however, are usually less severe in developing countries,
with strictly limited resources [1]. An example of this can
be given by comparing the great floods in Bangladesh
(1988) which caused the death of 1410 people with the
Mississippi flood in the USA in 1993, which only caused
about 30 fatalities. However, when one compares the
economic losses of the two events, the result are rever-
sed: in Bangladesh a total loss of 1.1 Billion US$ was
estimated versus 15.8 Billion US $ in the US. Even more
striking is a comparison between the hurricane disasters
of 1990 in Bangladesh and the 1992 hurricane Andrew in
the US.
These statistics illustrate well the importance of hazard
mitigation. The International community has become
aware of the necessity to increase the work on disaster
management. The decade 1990 - 2000 has been desi-
gnated the "International Decade for Natural Disaster
Reduction" by the general assembly of the United Nati-
ons. To reduce the impacts of natural disasters a com-
plete strategy for disaster management is required [4,5],
involving the following aspects:
* Disaster prevention
- Hazard analysis: assessing the probability of
occurrence of potentially damaging phenomena.
- Vulnerability analysis: assessing the degree of
loss expected to population, infrastructure, and
economic activities, as the consequence of an
event of a certain magnitude.
- Risk assessment: assessing the numbers of
lives likely to be lost, the persons injured, dama-
ge to property, and disruption of economic activi-
ties caused by a particular natural phenomenon.
- Landuse planning and legislation: implementati-
on of a risk map in the form of building codes
and restrictions.
* Disaster preparedness
- Forecasts/warning/prediction of disasters (for
example hurricane warning).
- Monitoring: evaluating the development through
time of disasters (for example floods).
* Disaster relief
- Damage assessment shortly after the occur-
rence of a disaster.
Defining safe areas to indicate possible escape
areas.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B6. Vienna 1996
