CONCLUDING REPORTACTION PLAN TOWARD EFFECTIVE FLOOD
HAZARD MAPPINGIN KOPONG SPEU CITY CAMBODIAThe Region-focused Training Course on Flood Hazard
Mapping
JFY2006

LONG SARAVUTH/Hydrologist
Department of Hydrology and River works
Ministry of Water resources and Meteorology#576 National Road N2 Sangkat Chak Angre Kram Phnom Penh, CAMBODIA

Email: lsaravuth@online.com.kh, dhrw.cambodia@online.com.kh.

Long Saravuth- Cambodia

A)THE ROLE OF FLOOD HAZARD MAPS TO MITIGATE FLOOD MANAGESIN CAMBODIA
A-1-The flood Status in Cambodia
Cambodia is one of the fourteen countries in Asia considered to be the most prone tonatural disasters. Natural disasters to which the country is subjected include floods (themost serious), drought and tropical storms. Man-made disasters include fire, transmitted
diseases, and landmines that lie buried along Cambodian-Thai border.
The flooding that occurs every year throughout the basin of the Mekong River in
Cambodia as a result of seasonal rains is the only one phenomenon that makes thecountry one of the most disaster-prone areas. Such flooding has caused the loss of lives,properties, destruction of public infra- structures and hindered the agricultural production.
Cambodia's vast flood plain is one of the country's most prominent geographical features,making large portions of the country prone to flooding by the Mekong River and from theheavy rainfalls. The majority of the Cambodian people living in these low-lying areas
depend upon subsistence farming for their livelihoods. Thus, the yearly occurrence offloods and other disasters results in grave consequences in terms of impacts on social,economic, productive aspects for rural population throughout the country andinfrastructure in provinces along Mekong River and around Tonle Sap Great Lake. The
Royal Government of Cambodia expresses deep concerns about the climate change, andespecially the Mekong flood as it reaches extremely high water level.
In 1991, some parts of the countries experience a serious drought and flood causingwidespread crop failures in some areas. Both problems-drought and flood-are likely to
become worse as a consequence of the rapid deforestation in large areas of the country.
The flooding of 2000 reportedly the worst in more than 70 years (1961, 1966,1978, 1984,1991 and 1996) put the death toll at 347, which 80% were children. More than 3,000,000
of people were affected and nearly 400,000 individuals had to be temporarily evacuated.
Furthermore, more than 300,000 houses were damaged and 7,000 were destroyed.
Hundred of school buildings, health centers and other infrastructures were also seriouslydamaged. The total damage costs was estimated at US$ 157 million.
Consecutively, in 2001 and 2002, Cambodia was again affected by Mekong flood anddrought. The same affected areas continue to get the impacts on social, economic,cultural and educational aspect, and infrastructure, but not so serious like the big flood in2000 due to the better implementation of disaster planning to minimize the damages andensure a safe community free from threat of flood.
• Death toll: 347• Houses affected: 317,400 houses (destroyed 7,000)• Education - Schools: 988 damaged in 13 provinces• Health - Health centers damaged 138• Production -Rice crop destroyed: 374,000 ha, Other crops destroyed: 47,000 ha,
Livestock lost: 3900heads• Infrastructure -National & provincial road damaged: 2,600 km, Secondary road,damaged: 1,500 km , Rail road damaged: 34 km , Bridges: 115 sites damaged,Wells, culverts: 11,900 damaged, Irrigation systems damaged: 123 sites

Long Saravuth- Cambodia

Comparison of Flood Impacts on Population
Year
1996
2000
2001
2002

Household386,132
750,618
429,689
296,234

Impacts
People2,029,748
448,629
2,121,952
1,439,936

Death toll
169
347
62
29

A-2-The Outline of the present counter measures for mitigating flood damages inCambodia
The MOWRAM has the right to prohibit activities that are likely to damage flood
protection works or to obstruct the natural flow of rivers. Structural (curative) as well as
non-structural (preventive) measures have been proposed to alleviate the floodingproblem.
Structural Measures• Flood Control Dams
Some examples of dams specially constructed for flood mitigation are Kob Srov Damand Tamok Dam built by MOWRAM for water supply, Irrigation but also serves as aflood mitigation dam.
• River WorksRiver works, which are carried out by Office River Works are realignment andcanalization of river channels, including widening and deepening to improve originalundersized channels.
Non-structural Measures
Non-structural measures are employed more for preventing floods from occurring andwith the aim of minimizing losses due to flooding. Some of these measures are:• River Basin Management
Under the concept of River Basin Management, the whole river basin is planned in an
integrated manner and all factors are taken into consideration when a certain development
plan is proposed. Factors like zoning for river corridors, riparian areas, natural flood plain,conservation of wetlands, storage ponds etc will be taken into consideration when
preparing flood management plans.
• Flood Forecasting and Warning System
Telemetric forecasting systems have been installed in the major river basins namely
Stung Treng, Kratie, Prek Kdam and Kompong Loung flood forecasting systems andflood marks have been established in smaller basins.
Department Hydrology and River Works also provides a bulletin and web-site
information system on flood warning and flood response will be functional after the flood

Long Saravuth- Cambodia

event occurs especially during the monsoon season. It’s included with the five main
activities as below:•••••‘Pre’ flood, ‘During’ flood and ‘Post’ flood
Flood forecasting and warning system
Flood disaster management, flood fighting, evacuation
Flood operation and relief centers at District, State and Federal levels
Flood damage assessment•First Warning is made to the Public by Minister / Secretary of State(MOWRAM) when both observed and forecasted levels exceed the WarningLevels.
Second Warning is made to the Public by Minister/Secretary of State(MOWRAM) when both observed and forecasted levels rise closely to theFlooding Levels.
Flood Alarming is made to the Public by Minister/Secretary of State(MOWRAM) when both observed and forecasted levels exceed the FloodingLevels.

••

Picture of Flood Information Board.

Picture of Flood Marks

A-3-Do you think flood hazard maps will be useful in Cambodia
Flood Hazard Map is very useful to be implemented in Cambodia. With regards of theFlood Hazard Map objectives, to prevent loss of people’s lives and helps smooth refugee
from home to evacuation shelter as well as to notifying the residents of potential flood
damage and enhancing their awareness of the importance of flood disaster preparedness
could be achieved.

Long Saravuth- Cambodia

B)THE ALLOCATION OF ROLE IN MAKING FLOOD HAZARD MAPS IN
CAMBODIA
B-1-Organization should hold the main responsibility for making a fundamental
map such as anticipate inundation area map.
NoAgency
Role1
Ministry of Water Resources and-Planning, coordinating and supervising
Meteorology
relief-Operations during flood. Support the flood
disaster preparedness activities among thecommittee members.
- Providing flood forecasting and warning
service to the public.
- Main organizations for planning, prepareand disseminate Flood Hazard Map.
-Providing weather forecast information dueto flood forecasting and warning activities
2Ministry of Finance-Prepare budgets for five yearlydevelopments.
3
Ministry of Environment-Support and provide development allocation
for flood mitigation projects at the federallevel.
4

Ministry of Land

5

Provincial Government-Providing the digital topographic map, DEM
of the drainage basin-Support and provide development allocation
for flood mitigation projects at the state level.
- Dissemination of Flood Hazard Map- Provide information on evacuation routes intheir region.

B-2-Organization should hold the main responsibility for making and disseminating
flood hazard maps.
NoAgencyRole
1
Ministry of Water Resources and-Making Flood Hazard Map.
Meteorology-Dissemination of Flood Hazard Map
2
Ministry of Finance-Prepare budgets
3
Ministry of Environment-Support
4
Ministry of Land
-Providing the digital topographic map, DEM
of the drainage basin
5
Provincial Government- Dissemination of Flood Hazard Map
6
National Committee for Disaster- Dissemination of Flood Hazard Map
Management.
7
Cambodia Red Cross- Dissemination of Flood Hazard Map

Long Saravuth- Cambodia

C)THE ACTION PLAN OF MAKING FLOOD HAZARD MAPS IN CAMBODIA
C-1-Stung Prek Thnot River Basin are the target area for flood hazard maps
The Prek Thnot River flows in the direction ofsoutheast to east from the Elephant mountainregion as origin. The highest elevation of thebasin is El. 1,543 m above mean sea level. The
schematic diagram of the Prek Thnot Riversystem is shown in Figure 1. The Prek Thnot
River joins the Bassac River at Kandal. Thecatchments area of the Prek Thnot River and thelength of river course are about 5,740 km2 and232 km at the confluence with the Bassac River.
The major tributaries and the catchments area ofthe tributaries are as shown here.

Figure 1 Target area Krang Ambel Village

Long Saravuth- Cambodia

Catchment Area of Sub-basin
Sub-basin
101 Ta Sal River
102 Trang Krang River
103 Areang River
104 Phleach River
105 Koun Tadak River106 Tang Haong River107 Krang Ambel River
Residual Basin
Total

Catchment
Area ( km2)
682
360
445
213
106
1,295
453
2,186
5,740

C-2-Necessary Stung Prek Thnot River Basin are the target area for flood hazard
maps
FHM is necessary to prevent loss of people’s lives and helps smooth refugee from home
to evacuation shelter as well as to notifying the residents of potential flood damage andenhancing their awareness of the importance of flood disaster preparedness
Statitic table along Stung Prek Thnot River Basin
Province
Kampong Speu
KandalTakeo
Total
DistrictAoral,
Chbar Mon
Kong Pesi,
Phnom Chrouch
Samrong Tong

Kandal SteungAng Snoul

Bati

8

Number of Commune

4332

479

Population

329,309

145,525

30,942505,776

Household63,576

29,4196,152

99,147

Rice field

55,14319,0487,130

81,321

New Rainfall Gauging Stations
No.

Station Name

Equipment

District/Village

1

Kirirom

Automatic2

Wat Kdey Lvea

3

Location (UTM)
Northing

Easting

Phnom Sruoch

1252931396882

Automatic

Samrongtong

1268598

462114Kong Pisey

Automatic

Kong Pisey

1247922459627

4

Trapeang Chour

Automatic

Aoral

1306348405995

5

ThpongAutomatic

Thpong12991154385596

Peam Khley

Phnom Sruoch

12675664307407

Phum Chum

Automatic
Automatic

Aoral

1294020383194

Roleang Chrey

Automatic

Samrongtong

1264829

439962Prey Kaniech

Automatic

Phnom Sruoch

1262000

409200O Kon Trom

Automatic

Phnom Sruoch

1238125

417515

8910

New Water Level Gauging Stations
No.

Station Name

Equipment

District/Village

1

Peam Khley Bridge

Logger & S.G.

2

Thnuos Luong

3

Location (UTM)
Northing

Easting

Phnom Sruoch

1266500

430871

Logger & S.G.

Chbr Mon

1266357446561

Krang Chek

Logger & S.G.

Phnom Sruoch

12610824024584

Cheneang Kpuos

Logger & S.G.

Phnom Sruoch

1265906

427244

5

Sangkea Tasal

Logger & S.G.

Aoral

1290500

4050006

Trapeang Kchon

Samrongtong

1267436458215

7

Roleang Chrey

Logger & S.G.
S.G.

Samrongtong

1265095

440236Prey Mean

S.G.

Aoral

12858724068188Long Saravuth- Cambodia

C-3-Five years Action Plan for flood hazard maps Stung Prek Thnot River Basin
Floodplain Management Plan study for one of the proposed area will possibly be carried out,Flood Hazard Map for any of the area will at the same time be made. Opportunities to effectively
put in and come up with Flood Hazard Map in the study will be a good ground for testingknowledge and experiences gain in this course. It is also necessary to foresee on how floodhazard map can be developed for other river floodplain. Summary of general action plan within 5years ahead as follow:

YearAction Plan

2007

- Deliver a presentation of FHM to my department- Formed the committee members of FHM- Gain and enhance my knowledge in anticipatedinundation area mapping, Topographic Map and GIS (FloodRunoff Analysis)- Check the viability and update topographic map at
Department of Survey Mapping and Data collecting- Having some meeting and understanding of FHM
between the related organizations- Get an opinion and idea from the local residents’perspective of FHM

2008- Promote the idea of FHM to the local government.
- Educating people and enhancing their awareness due
to flood disaster preparedness- Start planning and doing some ground works of FHM
for rural area. Target area

2009

- Carry out survey to study effectiveness –DHRW- Model construction (consists Topographic Modeling,
Flood Modeling and Flood Stimulation).

- Model construction (consists Topographic Modeling,
Flood Modeling and Flood Stimulation)(cont …)
2011- To disseminate the completed FHM to the target
group (State Resident)- Educating people and enhancing their awareness due
to flood disaster preparedness- Carry out survey to study effectiveness Stung Prek
Thnot River Basin- To conduct survey via questionnaire to the target
groups with the view to improve the usefulness of the FHM
2010Long Saravuth- Cambodia

C-4-Problem
Problems that might be faced in the process of developing Flood Hazard Map in Stung Prek
Thnot can be divided into aspects as follow:• Insufficient data (hydrological and topographic)
It is recognized that numerical simulation at best possible is one of the most important part offlood hazard mapping. In Stung Prek Thnot, installation of gauging station to capturehydrological information have year ago covered most part of the state and lack of data isanticipated to be one of the constraint. Topographic data of flooded area will be anotherconstraint in coming up with anticipated inundation area for particular area. Alternatively, any
kind of possible statistic method in acquiring hydrological data for un-gauge river basin as well as
any available topographic information will be utilized as best as it can.
• Community awareness level
In view of the impact of introducing flood hazard map as non-structural measure in reducing andpreventing lost of human life, it is expected that certain level of community will have different
perception of the map. There might be group of community looking it as threat rather thaninformation for preparedness and any other perception related to properties value or so. Effective
awareness rising and community consultation in the initial stage of the map development will be
helpful to overcome this problem. Working with community based non-government organization
to carry out this is also a possibility.

Suggestions for making this training course more meaningful
Exercise session such as the rainfall-runoff analysis should be given more time as it isone of the important technical knowledge necessary for production of inundation area
map. Especially software for analysis should be given more time for practice.
The participants that have done something or manage to come up with flood hazard
mapping in his/her country if possible invited to give lecture and share his experiences on
how he gone through the actual process in the next course.
Concluding remark
As mentioned earlier, Flood Hazard Mapping will be definitely beneficial to the management andreductions of damages caused by flood in Cambodia generally and Stung Prek Thnot particularly.
Since flood hazard mapping has not yet being carried out in any part of Stung Prek Thnot, thistraining course has provide the opportunities for government of Cambodia to enhance its floodhazard map and for Stung Prek Thnot to start in certain level to produce flood hazard map.
Consideration, support and willingness of Japanese Government Agencies especially Japan
International Cooperation Agency (JICA), Public Works Research Institute (PWRI) and all theparticipating country in relation to the training course are highly appreciated.

Long Saravuth- CambodiaD)THE FLOOD HAZARD MAP ON ISE CITY

HAZARD MAP ON ISE CITYBAD POINT AND GOOD POINT
C-4-The improvement from the FHM on Ise city.
The improvement from the FHM on Ise city are :• -Improve the professional knowledge of hydrology, hydraulics andriver engineering necessary to produce flood hazard maps,• -Improve the effectiveness of flood hazard maps and how todisseminate and utilize them for people,• -Improve the methods to enhance people’s capability
and promote public awareness to mitigate flooddamage,• -Improve an understanding of the way to produce andapply flood hazard maps

Long Saravuth- Cambodia