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