Risk Returns

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Preventive risk reduction

through space technology

Dr. Anond Snidvongs, Acting Executive Director,

Geo-Informatics and Space Technology Development Agency, GISTDA, Thailand

espite having a geographic location that renders it rela-

tively less exposed to extreme weather and geological

events than many other countries, Thailand is still vulner-

able to various types of natural disasters. However, due to lack

of awareness, coupled with development processes that have not

appropriately taken into consideration climate and geomorpho-

logical settings, some systems and sectors have frequently been

placed at unnecessarily high risk, lowering their capacities to

cope with events when they occurred. Floods, droughts, land-

slides, forest fires and tsunamis are examples of natural disasters

that have taken place in Thailand over the past decade, claiming

thousands of lives, displacing hundreds of thousands of people

and costing tens of billions of dollars in damages.

Satellite monitoring

Satellite-based images, both from optical and radar sensors, have been

used for the monitoring and assessment of disaster events in Thailand

for more than 20 years through the efforts of the Geo-Informatics and

Space Technology Development Agency and its precursor, the Remote

Sensing Division of the National Research Council of Thailand.

An operational system was set up in 2010 to provide satellite images

and other geo-information in support of national efforts to cope with one

of the worst floods ever to hit Thailand. More than 50 out of the coun-

try’s 76 provinces were affected by flash and prolonged flooding that

lasted more than two months. About 10 million people and one million

households were directly hit, with almost 200 fatalities. Public infra-

structure and vast agricultural areas were severely damaged. Regularly

updated assessments of inundated areas, taking into account the condi-

tions of roads, bridges, etc., were made available to national and local

agencies in both online and offline mode to assist their response and

relief efforts. Geospatial information also enabled the national

ad hoc

committee on floods to monitor and evaluate the effectiveness of reha-

bilitation and compensation for flood victims countrywide.

Tracking water sources

Drought is another disaster that occurs annually during the dry

season from December to April in Thailand. Images from high

resolution satellites, including our own Thailand Earth Observing

Satellite (THEOS), have been used to monitor water sources of

various sizes, from reservoirs measuring hundreds of square kilo-

metres to community ponds. The information gathered enables

responsible line agencies to plan and manage water allocation and

distribution to communities affected by drought.

As part of preventive preparation for flood- and drought-prone

areas, satellite-derived land classification and terrain models of the

areas have been made available to the general public and

concerned agencies. Areas that were frequently flooded

have been analysed to determine the frequency and

return periods so that flood risks can be estimated and

appropriate measures taken to minimize the vulnerability

of human lives and societies. In addition, our web-based

disaster information portal will soon feature a hydrologi-

cal forecasting system that, coupled with a downscaled

numerical weather prediction model, can be assimilated

with space-based rainfall estimation technology such as

TRMM (Tropical Rainfall Measuring Mission).

Coordinating the response

Lessons have been learnt from disaster cases in

Thailand, both during the events and from post-disaster

preventive measures. It is clear that in the immediate

response phase, relief efforts have been

ad hoc

and

coordination poorly organized. Centralized coordi-

nating bodies in the capital city of Bangkok usually

have good access to satellite images and other GIS data

necessary to evaluate the overall situation. However,

the communication and distribution of such informa-

tion to provincial levels and to relief teams in the field

through the existing communication channels remains

inefficient. Geospatial information needs to be proc-

essed, bundled and repackaged to match with users’

requirements, capacity and urgency.

Information with inappropriate time and space char-

acteristics could also confuse operators in the field and

delay relief efforts. The Internet and cellular phones are

usually not the best option for communication because

the transponder cells could be damaged or the cellular

networks could be jammed by heavy communication

load during a disaster.

Educating communities

Long-term preparation for disasters in Thailand

has been overwhelmingly focused on reducing the

exposure of systems and sectors to threats posed by

extreme natural events such as heavy rainfall, storm

surge, tsunami, etc. by building engineering struc-

tures such as dykes and seawalls to protect or isolate

certain areas from natural phenomena. Although

risks could be reduced this way, frequently new

issues or conflicts have been raised regarding their

2025