Effects of the tsunami disaster on society, economy and environment in Krabi province with special emphasis on Phi Phi Islands

Effects of the tsunami disaster on society,
economy and environment in Krabi
province with special emphasis on Phi Phi
Islands



Supervisor:
Prof. Florian Siegert

Students:
Jasmin Horn, Jenni Simkin, Ninni Saarinen, Liisi Koivisto, Maija Kaukonen, Nora
Sylvander, Klaus Dons, Andreas Langner

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Index
INDEX ............................................................................................................................................................................... 2
INTRODUCTION ............................................................................................................................................................ 3
1 BACKGROUND OF THE INDIAN OCEAN TSUNAMI DISASTER..................................................................... 3
1.1 A TSUNAMI STRIKES.................................................................................................................................................. 3
1.2 WHAT IS A TSUNAMI?................................................................................................................................................ 3
1.3 INDIAN OCEAN TSUNAMI .......................................................................................................................................... 4
2 ROLE OF GIS AND REMOTE SENSING IN DISASTER MONITORING .......................................................... 4
2.1 INTRODUCTION ......................................................................................................................................................... 4
3 TSUNAMI EFFECTS IN KRABI PROVINCE .......................................................................................................... 7
3.1 ENVIRONMENTAL EFFECTS........................................................................................................................................ 7
3.2 EFFECTS ON FORESTS ................................................................................................................................................ 8
4 NATIONAL AND PROVINCIAL RECONSTRUCTION ACTIONS...................................................................... 8
4.1 ENVIRONMENTAL RECONSTRUCTION ........................................................................................................................ 8
4.2 SOCIAL AND ECONOMIC RECONSTRUCTION ............................................................................................................... 9
4.2.1 Houses and schools .......................................................................................................................................... 9
4.2.2 Health care....................................................................................................................................................... 9
4.2.3 Fishermen supporting ...................................................................................................................................... 9
4.2.4 Unemployment supporting ............................................................................................................................... 9
4.3 WARNING SYSTEMS ................................................................................................................................................ 10
4.3.1 Warning System Center .................................................................................................................................. 10
4.3.2 New Tsunami Early Warning System (EWS).................................................................................................. 10
4.4 INTERNATIONAL ACTIONS ....................................................................................................................................... 11
4.4.1 Green Coast Project....................................................................................................................................... 11
5 TSUNAMI EFFECTS ON PHI PHI ISLANDS ........................................................................................................ 12
5.1 INTRODUCTION TO PHI PHI ISLANDS ....................................................................................................................... 12
5.2 TSUNAMI DESTRUCTION ON PHI PHI ISLANDS ......................................................................................................... 12
5.2.1 Effects on people ............................................................................................................................................ 12
5.2.2 Effects on property ......................................................................................................................................... 13
5.3 HELP INTERNATIONAL PHI PHI................................................................................................................................ 13
5.4 SEMI-STRUCTURED INTERVIEW ON PHI PHI............................................................................................................. 14
5.5 REESTABLISHMENT OF INFRASTRUCTURE ON PHI PHI ISLANDS............................................................................... 14
5.6 THE FUTURE OF PHI PHI ISLANDS ............................................................................................................................ 15
6 FUTURE PLANNING AND DEVELOPMENT ....................................................................................................... 16
6.1 THE COORDINATING COMMITTEE ............................................................................................................................ 16
6.2 RESTORING SUSTAINABLE LIVELIHOODS................................................................................................................. 16
6.3 THE GOVERNMENT’S REHABILITATION PLAN AND STRATEGY ................................................................................. 17
7 FUTURE LONG TERM PROJECTS NEEDED IN TSUNAMI AFFECTED AREAS ........................................ 17
8 CONCLUSIONS .......................................................................................................................................................... 18
REFERENCES ............................................................................................................................................................... 18


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Introduction

Tsunami disaster on 26th December 2004 caused 150 to 300 000 deaths. This report focuses on
effects of the tsunami disaster on the society, economy and environment in Krabi province with
special emphasis on Phi Phi Islands. It shows the results of studies on the following points:
- Overview of the tsunami disaster effects in Krabi province
- Role of GIS data
- Reconstruction and international actions
- Environmental and agricultural effects
- Future planning and the development



1 Background of the Indian Ocean tsunami disaster
1.1 A tsunami strikes
In the early morning of December 26, 2004 an earthquake of 9.0 magnitude under the Indian Ocean,
near the west coast of Sumatra generated a tsunami. The waves reached the coastline of 11 Indian
Ocean countries within few hours from the quake killing estimated 150,000 – 300,000 people.
Tsunami of the December 26 was destructive especially on the surrounding Asian countries but the
wave travelled nearly 5,000 km to the African coast still with enough of force to kill people and
destroy properties. (http://news.nationalgeographic.com/news/2004/12/1227_041226_tsunami.html)
The Indian Ocean tsunami can be ranked as one of the most destructive natural disasters to have
afflicted the Asian and Pacific region in modern times. This disaster differs from the earlier ones
because of its global dimensions, as many countries around the world, especially in Europe – far
away from the disaster area – suffered from casualties in high numbers. Many of the people affected
by the tsunami were foreigners, mainly tourists from Europe, but most of them were local people
making their living from fishing and tourism, which are considered to be the industries that took an
immediate hit and need time to recover. (Proksch 2005)
1.2 What is a tsunami?
Tsunamis are fairly common in Japan and many thousands of Japanese have been killed by them in
recent centuries. The term tsunami comes from the Japanese language meaning harbour and wave.
(National Geographic News 2006)
Tsunami is a series of great sea waves caused by an underwater earthquake, landslide, or volcanic
eruption. An earthquake generates a tsunami if it is of sufficient force and there is a vertical and
heavy movement of the earth causing great and sudden displacement of a massive amount of the
overlying water. Tsunamis travel outwards from the epicentre of the earthquake and in all
directions.
A tsunami is not a single wave but a series of waves, which also is known as a wave train. The first
wave in a tsunami is not necessarily the most destructive and the waves can come hours apart.

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A tsunami may be less than 30 centimeters in height on the surface of the open ocean, which is why
they are not noticed by sailors. But the powerful shock wave of energy travels fast through the
ocean at an approximate speed of 700 km/h (200 m/s), depending on the depth of the water.
Tsunami is controlled by water depth – when the wave reaches the shallow water near the coast it
starts to slow down. The top of the wave moves faster than the bottom, which causes the sea to rise
dramatically. The longer and more gradual the shallowing of the water is the more higher the
tsunami wave is. This is because it gives more time for the wave to interact with its surroundings
and cause extensive damage to lowland areas.
1.3 Indian Ocean Tsunami
The earthquake near Sumatra was the result of the sliding of the India plate under the Burma plate.
The process has been going on for thousands of years, one plate pushing against the other until
something has to give in. The result on December 26 was a rupture that was more than 1,000
kilometers (estimated by USGS) long, displacing the seafloor above the rupture by estimated 10
meters horizontally and several meters vertically. The moving of the trillions of tons of rock caused
the Earth to move with the largest magnitude earthquake in 40 years. It has been reported that the
earthquake caused waves as high as 10 meters in Southeast Asia.
Indonesia was the most damaged country of the ones affected with more than 120,000 dead and
another 100,000 missing (http://w3.whosea.org/LinkFiles/Reports_Tsunami_and_after-
indonesia.pdf).
In Thailand 6 provinces were affected by the tsunami. Most severely hit provinces were Phang Nga,
Krabi and Phuket in Southeast Thailand by the Andaman sea. In Krabi some 23,000 people were
affected by the tsunami in some way. Approximately 1,400 people, of which some 700 were local,
died or are missing in Krabi. Most severely damaged area in Krabi province was the Phi Phi islands
where some 700 people died.
2 Role of GIS and Remote Sensing in disaster monitoring
2.1 Introduction
Due to the fact that such catastrophies affect wide areas it is absolutely necessary to use Geographic
Information Systems (GIS) technology and Remote Sensing (RS) to be able to assess such numbers
as mentioned before. Geographic Information Systems use different kind of layers which can be
superimposed, combined and used for any kind of calculation. It is even possible to do data mining
by combining information form different sources as optical and radar satellite imageries, airborne
sensors, elevation data and all kind of georeferenced ground measurements. With the help of GIS
these informations can be processed to obtain further informations revealing any kind of
relationships between them. Remote Sensing helps to obtain any kind of image data and it is the act
of getting information without directly touching the object. Images showing the extent of such a
disaster can originate from space borne and air borne sensors as satellites and planes. There is a
huge variety of different sensor types ranging from spatially high to low resolution systems being
sensitive to different spectral ranges. Remote Sensing in the sense of obtaining real pictures of
objects from a different point of view started long time ago as the first cameras were developed.

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Figure 1
Figure 2

Balloons and pigeons (Figure 1 and 2) were used to carry cameras to receive pictures form above.
Later on cameras were fixed on planes and even later satellites were used for this purpose. Landsat
1, which was launched in 1972 by the NASA, was the first of up to now seven satellites carrying a
sensor which was built for environmental monitoring. These sensors had comparable spectral
properties so that it is possible to compare images acquired 30 years apart. Beside many military
satellite systems there is also a wide variety of satallites providing non military informations. One
can distinguish between active and passive sensing systems. Active sensors are able to emmit
energy by themselves as radar systems. They are not dependent on radiation coming from the sun
as the passive sensors are. Nowadays computers are used to handle these huge amounts of data and
do image-processing in automatic or at least semi-automatic way.
Sensing the surface of the earth by satellite sensors has many advantages. One is ability to cover
huge areas with single images. These areas are very often so remote and inaccessible on the ground
that the only possible way to get any data is the use of remote sensing devices. But there are also
different kinds of disadvantages. For optical satellite sensor systems the radiance of the sun has to
penetrate the atmosphere twice before reaching the sensor which results in a high sensitivity to
atmospheric disturbances as for example clouds, haze and all kinds of reflectance effects. This is
especially disturbing in areas of the humid tropics where clouds are very abundant and it is often
not possible to receive an image of a certain area in a special time because of frequent cloud
coverage.
For the tsunami disaster which took place in the Indian Ocean Remote Sensing and GIS technology
was used for different purposes.
The very first goal is to get some kind of damage maps. By using RS and GIS it was able to obtain
an overview of the area which was affected by the tsunami. Visual classifications of destroyed areas
up to semi- and full-automatic change detection techniques were applied to know which areas were
destroyed in which extent. This data is necessary to coordinate the help activities and to know what
kind of help is needed and where. All kind of international and national governmental and non-
governmental organisations providing any kind of help had to be organised to be sure that the food,
water and other donations are evenly distributed. It is important to know if the infrastructure is still
intact to be able to reach the areas which really need the help. Roads and railways might have been
destroyed by the tsunami and this would make it necessary to use helicopters instead of lorries to
come to areas which are not accessible by car. Ancillary datasets as information about demographic
figures can be used to get an idea about the number of people affected in different areas. This can
help to predict what kind of problems might occur in the very near future e.g. problems in fresh

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water and nutrition supply. So it is possible to undertake the necessary steps to prevent such
situations. By the use of GIS and RS it is furthermore possible to identify areas of higher risk for
spread of diseases by combining information about the number of affected inhabitants and the
situation of the waste water management which might be out of order due to the disaster.
A lot of information can be obtained by analysing the impact of the tsunami in combination with all
kind of spatial patterns of the environment it affected. Another big issue is the identification of
spatial patterns in the damaged regions and the severity of the damage. By analysing these factors
while taking into account some ancillary data as digital elevation or terrain models, land cover
classifications showing different forest classes and data about the topology of the sea floor it is
possible to obtain information about the facts that are mainly involved in the severity of the tsunami
damage. The results show that low slopes in the bathymetry in shallow waters help to build up
waves having the highest impact compared to other underwater topologies. On the other hand if the
seafloor is deep and the shoreline is very steep there is no possibility for a wave to build up and the
tsunami will just result in a rising sea level and will have no impact on the land. Another effect for
the severity of the damages is the elevation and slope of the land surface. Areas close to the sea with
an altitude of less than 20 meters in combination with a very low slope are very prone to tsunami
disasters because the water is very easy to go land inward. Beside these it is also important to check
the shape of the shoreline for any funnel effects which can cause the wave to gain in height. And
one of the most important facts having great impact on the severity of a tsunami is the distance from
the epicentre. The closer the epicentre to the shoreline and the closer it takes place to highly
populated places the more dangerous is the damage caused by higher tsunami waves. By this
analysis it became clear that areas showing some kind of natural protection like mangrove, swamp
or beach forest were much less affected than similar ones without. The reason for this is that the
wave of the tsunami was able to disturb several meters of these forests but was then absorbed
somehow and caused just a rising water level. A similar kind of protection was offered by coral
reefs situated in front of the shoreline where the tsunami wave lost a lot of its energy.
The third very important information which can be extracted by the role of GIS and RS are future
risk maps. It is absolutely necessary to know about areas which can be hit by a future tsunami to be
able to undertake actions to prevent from possible future disasters or at least try to have the impact
as less as possible. Areas prone to such disasters have to have rescue roads and rescue areas to save
people’s lives. These areas must be situated on higher elevation to prevent being affected by the
water. For that purpose elevation data derived form radar devices can be analysed to derive such
higher altitude areas. For future planning it can be very helpful to avoid building new houses in high
risk areas. The same is true for new hotel complexes and any kind of new built infrastructure. Not
just avoiding areas prone to the impact of future tsunamis but using natural protection areas as
vegetation barriers such as mangrove forests and coral reefs will help to make future life close to
the shoreline more secure. By simulating different impacts of possible tsunami events it is feasible
to identify areas of different risk values. Such kind of tables may also be used in an economic point
of view helping to access the price of ground or the height of special insurances. Using this kind of
information also helps to identify areas where such kind of natural barriers should be
(re)established, e.g. planting new mangrove trees.
In our study we tried to establish such a kind of risk map showing areas with an elevation lower
than 20 meters and which are close to the shoreline. The first intermediate result was a map
showing all areas in red colour which are situated lower than 20 meters sea level (figure 3). In the
second step we buffered this region with a 500 meter buffer from the shore line towards the inland
to skip regions which are too remote to be affected by any tsunami (figure 4).

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figure 3
figure 4
Due to the little amount of time and the problem of getting access to any kind of seafloor topology
data it was not possible to take this data into account. Furthermore, it would be very interesting to
use a land cover map showing all different kinds of costal vegetation as well coral maps to be
included to this risk map. This would be very necessary to predict the impact of approaching
tsunami waves but due to lack of time this work was not feasible. So we decided just to
superimpose the risk map on the Landsat ETM+ image (figure 5) and the land cover classification
(figure 6).


figure 5
figure 6
The very last important point of processing such a risk map should be the act of validation. To do so
it is important to collect a sufficient amount of ground truth data using a GPS device.
3 Tsunami effects in Krabi province
3.1 Environmental effects
Tsunami did not affect heavily the environment in Krabi Province, although corals and forests were
damaged in some places (Governmental Office of Krabi). Especially in shallow waters the corals
had severe damages in some cases but little affect in water depth of 5 meter and deeper. (Wetlands
International-Thailand Office, Friday 7th January 2005). Some corals were thrown into the beach

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because of the power from Tsunami (personal discussion on Phi Phi Islands). Also5 percent of the
sea grasses were affected by the Tsunami. Water quality became little bit better in some places
because the water was mixed up and dirt was washed away. The effect on rare species was minimal
(Panel discussion in Krabi, 12.01.2006).
3.2 Effects on forests
There have been some changes in forestry department in Thailand in last three years. Royal Forestry
Department was divided into three different departments. Even though there are now three
departments there is only one law which rules all the actions related to forests. That is why
responsibilities between these departments are unclear. Because of that, it was difficult to get a
whole picture of the damages of the forest areas.
The most sever effects related to forests of the tsunami appear in Phi Phi Islands. Coconut
plantations suffered the most from the tsunami because they did not have appropriate root system
due to transportation from other sites. Total number of damaged coconut plantations is 69 rai in
which 27 rai of coconut trees were totally damaged and 42 rai were partially damaged.
Some of the beach forests in Krabi province were also damaged similarly as the coconut trees and
most of these trees were in Phi Phi Islands, ca. 75 rai. All the damages in beach forests occurred in
second layer of Casuarina sp. That is because the salinity concentration in the soil rose after
tsunami and the trees could not survive from that. Although Casuarina species have been in
Thailand for decades they are not indigenous tree species, they originally come from Australia.
The tsunami did not really effect the inland forests in Krabi province which are under the
responsibility of Provincial Forest Office according to the head of the office Mr. Pichai
Srisuuksomvong and his assistants. Despite that fact, there have been some reforestation actions in
Hong Island according to the Chief of Governor Office (CGO) Mr. Nattapong Sirichana.
Reforestation, to some extent, is also going on under National Parks in Krabi province.
Provincial Forest Office has provided altogether 8000 seedlings to people to replace their fallen
trees. Those seedlings include 5000 seedlings of mangrove species and 3000 inland species, for
example Casuarina, Ficus and Terminalia. Some of these seedlings have also been delivered to Phi
Phi Island.
4 National and provincial reconstruction actions
4.1 Environmental reconstruction
All environmental reconstruction actions have been completed except of reforestation. Some
planting of trees is still in progress. Local people have been involved in all reconstruction actions.
They have been collecting rubbish from the ocean and from the land. Beaches were the first areas to
be cleaned after thousand of tons of rubbish had been thrown on to the beach. The corals had been
damaged seriously in some places and less in others. Lots of rubbish had been collected to clear
corals. Environmental reconstruction actions were coordinated by the Ministry of Natural Resources
and Environment (Governmental Office of Krabi).

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4.2 Social and economic reconstruction
Totally 23,060 people were affected by tsunami on different ways and 2,632 families were
supported with a total worth of 58.23 million baht. An amount of 23.43 million baht were given to
1,307 people. The Province of Krabi distributed 58,403 goods and supplies and out of these 8,585
packages came from Krabi Red Cross (Governmental Office of Krabi).
4.2.1 Houses and schools
The tsunami left 119 orphans. The orphans were mostly students and they have received a support
of worth of 81.98 million baht. Totally three schools were damaged in Krabi Province. Two are
already rebuilt and one is still under renovation on Phi Phi Islands (Governmental Office of Krabi).
The tsunami damaged 924 houses of which 662 were completely damaged and 262 partially
damaged. The reconstruction plan is made for 382 permanent houses of which 149 are already
finished and 233 houses are under reconstruction. Basic support to rebuild houses came from Krabi
Red Cross worth 2.55 million baht. From 40 cases of Property Insurance 39 cases received money
worth 608.98 million baht (Governmental Office of Krabi).
4.2.2 Health care
Many people got injured by the tsunami in Krabi Province. 4,571 people got treatments worth of
17.4 million baht. Counselling therapy was given to 15,841 people and 2,759 families worth 1.97
million baht. After tsunami there was a disease control programme, which was worth 3.21 million
baht. Physical and mental rehabilitation is continuously given to the tsunami victims in several
districts (Governmental Office of Krabi).
4.2.3 Fishermen support
Already 5,000 fishermen have been supported with worth of 103.25 million baht. Still 237
fishermen are asking for additional financial support. They got already 9.36 million baht. Also
1,280 fishermen are waiting for the approval from the Department of Fisheries for financial support
(Governmental Office of Krabi). Totally 200 boats have to be built of which 84 are already finished
and given to people in Kao Thong. Thai Red Cross donated 22.8 million baht to build the boats
(Government Office of Krabi). Boats are still under reconstruction. Because of the logging ban of
Thailand’s forests, wood from Shorea tree has to be imported from Malaysia. Wood for one boat
costs 80,000 baht and the whole boat with engine costs 200,000 baht. It takes 8 days to build one
boat (Personal communication in Khao Lak).
4.2.4 Unemployment support
The Ministry of Labour gave urgent budget to help unemployed. This action took place in two
phases. First phase was worth 31.72 million baht and the second was 2.11 million baht. Local
Government Department helped 1,237 people by donating 24.74 million baht (Governmental Office
of Krabi).

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4.3 Warning systems
4.3.1 Warning System Centre
After the tsunami the government has established a nationwide warning system, which is linked to
the Pacific Tsunami Warning Centre (PTWC) in Ewa Beach, Hawaii. The Thailand-Centre Station
is located in Bangkok which communicates with the twelve nationwide units. One unit is also
located in Krabi.
After an earthquake seismographic information is transmitted over satellite signals to the Centre
Station, which forwards it to the headquarters in Hawaii and Chiang Mai. There the signals are
analyzed and it is determined if the earthquake has generated a tsunami. In case of a tsunami the
result is sent back to Bangkok, from where the information is given to the units.
People are then warned through warning towers, which give the warning in 5 languages (English,
German, French, Japanese and Thai). The warning is also given via the radio and to boats. Krabi
Province has 32 warning towers, 2 of them are located on Phi Phi Islands. The whole process after
detecting signals from earthquake to the given warning takes 45 minutes (Warning System Centre
in Krabi). False alarms can not be excluded.
Evacuation plan is established on Phi Phi Island, which includes information about the fastest way
to one of several collecting points. Tourists get this plan after check in from their hotel. Most of the
tourists who are now on Phi Phi feel safe and are not afraid of a tsunami, but in some cases there is
a wrong opinion, that a new tsunami after 2004 is not expected (personal communication with
tourists on Phi Phi Island).
4.3.2 New Tsunami Early Warning System (EWS)
The National Research Centre for Geosciences in Potsdam/Germany has developed a new Early
Warning System, which is based on measurements of water pressure after an earthquake. This is
more effective, because it can better determine, whether an earthquake causes a tsunami or not, so
that there is likelihood of false alarm occurrence. But the most important advantage of this new
system is that the people can be warned much faster.


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