Assessment of flood forecasting and Assessment of flood forecasting and warning system for Tropical Regionswarning system for Tropical Regions

Study Countries: Indonesia, Malaysia, Vietnam, PhilippinesStudy Countries: Indonesia, Malaysia, Vietnam, Philippines

Participating Orgs: IHPParticipating Orgs: IHP--National Committee Study Countries; National Committee Study Countries; ICHARM; HTC Kuala LumpurICHARM; HTC Kuala Lumpur

Project Team Leader: Dr. Mohamed Nor (Malaysia)Team Members: Dr. H.Pawitan (Indonesia), Dr. Guillermo Tabios III

(Philippines), Dr. H. Thuyen/Dr. Ahn (Vietnam)

November 3, 2009

Outline of PresentationOutline of Presentation

••Study Objectives and Final Report ContentsStudy Objectives and Final Report Contents••Status of ProjectStatus of Project••Description of Study AreasDescription of Study Areas••Field VisitsField Visits••Final Report ContentsFinal Report Contents

Study ObjectivesStudy Objectives••Assessment of existing flood forerecasting and Assessment of existing flood forerecasting and warning system (FFWS) of the four study countries: warning system (FFWS) of the four study countries: Indonesia, Malaysia, Philippines and Vietnam. One Indonesia, Malaysia, Philippines and Vietnam. One specific river/watershed system to be studied in specific river/watershed system to be studied in each country have been selected.each country have been selected.

••Review of stateReview of state--ofof--the art FF methods and models the art FF methods and models including rainfall forecasting techniques such as including rainfall forecasting techniques such as ‘‘nowcastingnowcasting’’ methodsmethods

••Visit watershed of each of the four countriesVisit watershed of each of the four countries

••Analyze, synthesize and propose an improved FF Analyze, synthesize and propose an improved FF model and FFWS based on field visit, experiences model and FFWS based on field visit, experiences from different countries including statefrom different countries including state--ofof--artart--techniques.techniques.

••Final report (contents next slide).Final report (contents next slide).

Final Report OutlineFinal Report Outline1.Introduction

1.1 Background2.Study objectives3.Description of study areas

3.1 Hydrometeorology regime3.2 Hydrometeorological network3.3 History and characteristics of floods events3.4 Objectives and needs of FFWS

4.Review of current practices and State-of-the-Art of Technology4.1 Field visits4.2 Data Collection and Flood Monitoring in Study Areas

4.2.1 Hydrometeorological data4.2.2 Flood monitoring (measurement, visual, etc) system

4.3 Existing FFWS in Study areas4.3.1 Current technology used4.3.2 Dissemination of flood information and flood warning4.3.3 Effectiveness and problems

4.4 Improved modeling tools used for FFWS4.5 Improved dissemination tools of flood information and warning

5.Major findings5.1 Assessment and Propose Improvement5.2 Comparison and assessment of existing FFWS 5.3 Proposed improvement to FFWS

6.Conclusions and recommendationsREFERENCES

Status of Project and ScheduleStatus of Project and Schedule••First Meeting held in Kuala Lumpur, Malaysia in April First Meeting held in Kuala Lumpur, Malaysia in April 2020--24, 2009 and also field visit of Klang River System24, 2009 and also field visit of Klang River System••Second Meeting held in Bogor, Indonesia in July 16Second Meeting held in Bogor, Indonesia in July 16--19, 2009 and field visit to Ciliwung River System19, 2009 and field visit to Ciliwung River System••Third Meeting held in Danang, Vietnam in October 7Third Meeting held in Danang, Vietnam in October 7--10, 2009 and also field visit to Thu Bon River System10, 2009 and also field visit to Thu Bon River System••Fourth Meeting to be held in Manila, Philippines Fourth Meeting to be held in Manila, Philippines scheduled in January 13scheduled in January 13--16, 2010 and to visit Marikina 16, 2010 and to visit Marikina River SystemRiver System••Project Progress Report in Wuhan, China on Project Progress Report in Wuhan, China on November 3, 2009.November 3, 2009.••Submit Final Project Report by first week of March, Submit Final Project Report by first week of March, 2010.2010.

Bogor, Indonesia July 16-19, 2009

Danang, VietnamOctober 8-10, 2009

Selected River/Watershed System from Each Selected River/Watershed System from Each CountryCountry

••Ciliwung River in IndonesiaCiliwung River in Indonesia••Klang River in MalaysiaKlang River in Malaysia••Marikina River in PhilippinesMarikina River in Philippines••Thu Bon River in VietnamThu Bon River in Vietnam

Summary of Preliminary Assessment of FFWS of Indonesia, Summary of Preliminary Assessment of FFWS of Indonesia, Malaysia, Philippines and Vietnam River Systems StudiedMalaysia, Philippines and Vietnam River Systems StudiedSystems and Issues Ciliwung River

(Indonesia)Klang River (Malaysia)

Marikina River (Philippines)

Thu Bon River (Vietnam)

FFW System in general

Operational Operational Completed in 1990’s but not operational now

Not fully operational and needs updating

Data Monitoring Issues (hardware and software)

Yes None equipment working but no real-time data transmission

Yes

Coordination Issues (nat’l to local gov’t and to public)

Yes None Yes Yes

Information Dissemination Issues

radio, TV, local public address (PA)

radio, TV, local PA, internet, SMS

radio, TV, local PA, internet

radio, TV, internet

Rainfall Forecasting None but real-time rainfall available

None but real-time rainfall available

None None

Flood Forecasting Limited Yes Hardware available but not currently operational

yes using upstream observe water levels but no downstream inundation model

Land Use and Other Issues

Yes Yes Yes none

Details of studied river system and Details of studied river system and associated FFWS base on presentations by:associated FFWS base on presentations by:••Dr. Hidayat Pawitan for Ciliwung River in Indonesia Dr. Hidayat Pawitan for Ciliwung River in Indonesia (11 slides)(11 slides)••Dr. Mohamed Nor for Klang River in Malaysia (13 Dr. Mohamed Nor for Klang River in Malaysia (13 slides)slides)••Dr. Guillermo Tabios III for Marikina River in the Dr. Guillermo Tabios III for Marikina River in the Philippines (12 slides)Philippines (12 slides)••Dr. Hoang Minh Tuyen for Thu Bon in Vietnam (17 Dr. Hoang Minh Tuyen for Thu Bon in Vietnam (17 slides)slides)

CILIWUNG RIVER SYSTEMCILIWUNG RIVER SYSTEMINDONESIAINDONESIA

Location ofCiliwung  RiverWithin the GreaterJakarta Basin

Ciliwung River Slope 

DAS  Ciliwung  terletak  pada  dataran  landai,  bergelombang  hingga  pegunungan,  daerah  Katulampa ketinggian  sekitar  300  m dpl.    Sedangkan  daerah  berbukit  atau  bergelombang,  yaitu  mulai Kedungbodak ke arah selatan sampai daerah Tugu selatan (1057 m), semakin ke arah selatan dan timur termasuk daerah pegunungan yang merupakan batas DAS seperti, Gunung Halimun (1665 m), Gunung Mega Mendung (1672 m) dan Gunung Pangrango (3019 m). 

0 20 40 60 80 1000

500

1000

1500

2000

Gunung Mas

Megamendung

CiawiBogor Depok Manggarai

15080242203100263Angke

20205383110Pesanggrahan

8100292733Grogol

12550911773798Krukut

2001001029088117347Ciliwung

772812107123648Cipinang

1105512122124073Sunter

623094592330Buaran

8450109063355Cakung

Q25(m3/s)

Q2(m3/s)

tc1)

(jam)H2(m)

H1(m)

L(km)

A(km2)S U N G A I

Source : NEDECO‐PBJR (1973) 

Characteristics of  the Rivers Flowing to the Jakarta Bay

050

100150

200250300

350400

450500

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

Ting

gi m

uka

air

(cm

)

Monthly rainfall at Jakarta Obs 1971-2000

0

100

200

300

400

500

600

700

800

900

1000

Jn71

Nv7

1

Sp72

Jl73

My7

4

Mr7

5

Jn76

Nv7

6

Sp77

Jl78

My7

9

Mr8

0

Jn81

Nv8

1

Sp82

Jl83

My8

4

Mr8

5

Jn86

Nv8

6

Sp87

Jl88

My8

9

Mr9

0

Jn91

Nv9

1

Sp92

Jl93

My9

4

Mr9

5

Jn96

Nv9

6

Sp97

Jl98

My9

9

Mr0

0

Cur

ah H

ujan

(mm

)

Nama St. : Jakarta / BMG CH tahunan : 1841 mmNo St. : 27 SD : 399

Monthly rainfall at Bogor/Dramaga Sta1971-2000

0

100

200

300

400

500

600

700

800

900

1000

Jn71

Nv71

Sp72

Jl73

My7

4

Mr7

5

Jn76

Nv76

Sp77

Jl78

My7

9

Mr8

0

Jn81

Nv81

Sp82

Jl83

My8

4

Mr8

5

Jn86

Nv86

Sp87

Jl88

My8

9

Mr9

0

Jn91

Nv91

Sp92

Jl93

My9

4

Mr9

5

Jn96

Nv96

Sp97

Jl98

My9

9

Mr0

0

Cura

h Huj

an (m

m)

Nama St. : Bogor / Dramaga CH tahunan : 3973 mmNo St. : 44 SD : 600

PENDANGKALAN

L E M B A G A P E N E R B A N G A N D A N A N T A R I K S A N A S I O N A L ( L A P A N )

CITRA IKONOS SEBAGIAN DARI

WILAYAH CIKARANG (BEKASI)

Terjadi pendangkalanyang cukup luas di

beberapa bagian sungaiberdampak besar

pada terjadinya banjir

Deposition and Erosion Issues

Land Use in 1990 vs 1996

Runoff Curve Numbers in 1990 vs 1996 (Noted increases of 23%, 22% and 19% in Jakarta, Depok and Bogor areas, respectively.)

Runoff Changes from 1990 to 1996(PERUBAHAN PENGGUNAAN LAHAN TERHADAP ALIRAN SUNGAI)

Perubahan Land Use Ciliwung Tengah (1990-1996)

-2000-1500-1000-500

0500

10001500200025003000

Hut

an

Keb

un

Pem

ukim

an

Sawa

h

Tega

lanLua

s Per

ubah

an (h

a)

0

50

100

150

200

250

300

350

400

Deb

it pu

ncak

(m3/

dt)

Katulampa Depok Manggarai

Outlet DAS

19901996151,1 km2

246,4 km2325,8 km2

Perubahan Land Use Ciliwung Hulu (1990-1996)

-1500-1000

-5000

500100015002000

Hut

an

Keb

un

Pem

ukim

an

Sawa

h

Tega

lan

Luas

Per

ubah

an (h

a)

Perubahan Land Use Ciliwung Hilir (1990-1996)

-2500-2000-1500-1000-500

0500

10001500200025003000

Hut

an

Keb

un

Pem

ukim

an

Sawa

h

Tega

lan

Lua

s Per

ubah

an (h

a)

10

20

30

40

50

60

70

Pe/P

(%)

Hulu Tengah Hilir

Wilayah DAS

19901996

KLANG RIVER SYSTEMKLANG RIVER SYSTEMMALAYSIAMALAYSIA

LumpurKuala

S.Linggi

KELANTAN

Ipoh

Shah Alam

S.Perak

S.Bernam

Seremban

S.Klang

SELANGOR

Kangar

Alor Setar

George Town

PINANGPULAU

GKAWILAU

S.Muda

KEDAH

PERLIS

PERAK

THAILAND

S.Rompin

SINGAPORE

Kuantan

S.Pahang

S.Cukai

S.Muar

S.Batu Pahat

S.Benut

PAHANG

SEMBILANNEGERI

MELAKA

MelakaS.Melaka

JOHOR

S.Kuantan

S.Johor

BahruJohor

S.Endau

S.Dungun

Kuala Terengganu

Kota Bharu

TERENGGANU

S.Kelantan

S.Terengganu

LumpurKuala

S.Linggi

KELANTAN

Ipoh

Shah Alam

S.Perak

S.Bernam

Seremban

S.Klang

SELANGOR

Kangar

Alor Setar

George Town

PINANGPULAU

GKAWILAU

S.Muda

KEDAH

PERLIS

PERAK

THAILAND

S.Rompin

SINGAPORE

Kuantan

S.Pahang

S.Cukai

S.Muar

S.Batu Pahat

S.Benut

PAHANG

SEMBILANNEGERI

MELAKA

MelakaS.Melaka

JOHOR

S.Kuantan

S.Johor

BahruJohor

S.Endau

S.Dungun

Kuala Terengganu

Kota Bharu

TERENGGANU

S.Kelantan

S.Terengganu

S.Rejang

S.Sadong

S.Rejang

S.Sadong

S.SarawakS.SarawakKucingKucing

SARAWAK

S.BaramS.Baram

LABUAN

KotaKinabaluKotaKinabalu

SABAH

S.KinabatanganS.Kinabatangan

FLOOD PRONE AREA (EAST MALAYSIA)

S.Rejang

S.Sadong

S.Rejang

S.Sadong

S.SarawakS.SarawakKucingKucing

SARAWAK

S.BaramS.Baram

LABUAN

KotaKinabaluKotaKinabalu

SABAH

S.KinabatanganS.Kinabatangan

FLOOD PRONE AREA (EAST MALAYSIA)

Kelantan• Sungai Kelantan

• Sungai Golok• Sungai Semerak

Terenganu• Sungai Besut

• Sungai Dungun• Sungai Terengganu

• Sungai Kemaman• Sungai Marang• Sungai Chalok

Pahang• Sungai Pahang

• Sungai KuantanJohor

• Sungai Benut• Sungai Johor

• Sungai Batu Pahat• Sungai Muar

Selangor• Sungai Langat• Sungai Buloh

• Sungai Kelang• Sungai Bernam

• Sg. SelangorW.Persekutuan KL

• Sungai KlangMelaka

• Sungai Melaka

Negeri Sembilan• Sungai Linggi• Sungai Pahang• Sungai MuarPerak• Sungai Perak• Sungai Kerian• Sungai Kurau• Sungai SlimKedah• Sungai Kedah• Sungai MudaPulau Pinang• Sungai Juru• Sungai Muda• Sungai Pinang• Sungai Perai• Sungai JawiPerlis• Sungai Perlis• Sungai ArauSabah• Sungai Kinabatangan• Sungai PadasSarawak• Sungai Batang Sadong• Sg. Sarawak

Flood Prone Areas

Sun. 10 JUNE 2007

FLASH FLOOD IN KUALA LUMPUR ON 10 JUNE 2007

An Integrated Flood Forecasting and Warning System Control Centre for the

Klang Valley • 1,280 km2

• 120 km – Sungai Klang

• 11 main tributaries• Population of 4

million• 1,330 m at highest

point• 4 hours lead time• Tidal intrusion up

to Sungai Damansara

Kuala Lumpur

Shah Alam

Petaling Jaya

Ampang

Construction Cost = RM 24,749,400Modeling Cost = RM 4,617,737

KLANGGATES DAM

30 cumec

Sg Kerayong

280 cumec

300 cumec

Sg KerohSg Jinjang

Sg B

atuSg

Gom

bak

PWTC

Kolam Kg Benteng

(0.4 mcm)

Kolam Takungan

JinjangKolam

Takungan Batu

Kolam Kg Puah

100 cumec

275 cumec

400 cumec

290 cumec

35 cumec35 cumec

150 cumec

65 cumec

Lencongan Gombak (3.375

km)

Lencongan

Keroh

(2.2 km)

Sg KlangSg

Gom

bak

80 cumec

125 cumec

(2.5 mcm) (4.5 mcm)

BATUDAM

Masjid Jamek

Kolam Kg Berembang (0.6 mcm)

Kolam Taman Desa

(1.4 mcm)

Sg B

unus

45 cumec

180 cumec

100 cumec190 cumec

10 cumec

Sg K

lang

SMART Bypass Tunnel(9.7 km)

KUALA LUMPUR FLOODMITIGATION PROJECT

NOT TO SCALE

Kolam Sri Johor

(1.5 mcm)

(36.6 mcm) (25.1 mcm)

Radio, PSTNSatellite

Rainfall & River Level

Sensors14 Master Stations

DID Mailbox

DID National Flood

Monitoring Centrehttp:infobanjir.water.gov

.myWorld Wide Web

On-Line Flood Information “FLOOD-INFO”-schematic diagram

EmailProvider

RTU Stations

RTU Stations

Ulu Kelang Pandan Jaya

JPS AmpangAmpang Mewah

Control Centre

Majorpopulated area

RiversLakes

100 0 100 200 300 Km

N

EW

S

0 - 200200 - 500500 - 700700 - 10001000 - 12001200 - 14001400 - 17001700 - 19001900 - 2200No Data

Elevation (m)

Majorpopulated areaMajorpopulated area

RiversLakesRiversLakes

100 0 100 200 300 Km100 0 100 200 300 Km

N

EW

S

N

EW

S

0 - 200200 - 500500 - 700700 - 10001000 - 12001200 - 14001400 - 17001700 - 19001900 - 2200No Data

Elevation (m)0 - 200200 - 500500 - 700700 - 10001000 - 12001200 - 14001400 - 17001700 - 19001900 - 2200No Data

0 - 200200 - 500500 - 700700 - 10001000 - 12001200 - 14001400 - 17001700 - 19001900 - 2200No Data

Elevation (m)

Atmospheric Model-based Rainfall and Flood Forecasting (PMAMFF) System

User

Radar Rainfall Reflectivity Data

Ground model/DTM

Spatial Resolution

Recorded Rain Gauge Data

Event/Time Series length

Area/coordinated of interest

Data process

Rainfall precipitation

Input for hydrologicalmodelling

User

Radar Rainfall Reflectivity Data

Ground model/DTM

Spatial Resolution

Recorded Rain Gauge Data

Event/Time Series length

Area/coordinated of interest

Data process

Rainfall precipitation

Input for hydrologicalmodelling

Radar Rainfall Analyzer and Integrator for Malaysia (RAIM)

MERSING

SUBANG

MARIKINA RIVER SYSTEMMARIKINA RIVER SYSTEMPHILIPPINESPHILIPPINES

Weather and Rainfall System in Metro Manila

Metro Manila and Luzon in general of the Philippines derive their rainfall yield mainly from the following weather systems:

•Southwest monsoons which originate from the Indian Ocean during the “wet” season or the northern hemisphere summer (June to September),

•Rain intensification afforded by the tropical cyclones or typhoons which cross the country from either the western Pacific Ocean or China Sea,

•Thunderstorms associated with the inter-tropical convergence zone(ITCZ) which seasonally oscillates between north and south of the

equator..

•In most parts of the region, the “dry” season is during the so-called December to April while May and November are transitional months..

(JICA)

Study Area:

The Marikina River Basin (529 sq. km) is located northeast of Metro Manila drains to the Pasig River.

The Pasig River Basin is a highly urbanized river basin (702 sq. km.) and drains directly to Manila Bay

Nearby is the Laguna de Bay (Laguna Lake) Basin which is an extensive and urbanizing lake region southeast of Metro Manila. The total lake basin area is 3229 sq.km. composed of 21 tributary subbasins (2300 sq. km.), a lake area (929 sq. km.).

Laguna Lake is connected to Marikina-Pasig River through the Mangahan floodway (built in 1985) to serve as temporary storage of floodwaters from these two rivers.

MarikinaRiver

Pasig River

Lagunade Bay

ManilaBay

Tabak

Bosoboso

Pasig

Science Garden

101

102103

104

105

106107

108

109110

111

112

113

114

115

116

117

118

119 120

121122

123 124

125126

127

128

129

130131

132133

134135

136

137138

139

140

141

142143

144

145

146

147

148149

150

151152

153

154

155

156

157

158

159

160

161

162163

164

165166

167

168169

170

171

172

173

174

175

176177

178

179

180181182

183

184

Rainfall Stations

Rivers/Tributaries

Sub-Basin Divides

Marikina River Basin Boundary

LEGEND

Marikina River Basin

Sto. Nino Gaging Station

Sto. Nino Gaging Station

121 00'o

14 50'o

121 00'o

14 35'o121 20'o

14 35'o

121 20'o

14 50'o

Rosario Weir

Rosario Weir

NORTH

Marikina River Watershed Delineation

METRO MANILA FLOOD PROBLEM AND FLOOD CONTROL

Flood flows of the Marikina River, joining Pasig River•can inundate the lower parts of Metro Manila,•has to be diverted to Laguna de Bay during heavy monsoon and typhoon episodes via the so-called Mangahan Floodway controlled by an 8-gated weir inlet with a diversion capacity of 2400 cu.m/s),

With the floodflow diversions from Marikina River and its own natural tributary inflows,•Laguna de Bay becomes a temporary flood retention basin during the rainy season,•so that its higher water level (above Manila Bay) would prevent salinity or seawater intrusion•but unfavorable to traditional brackish-water aquaculture and fisheries.

The recession of the lake water level by outflow through the same Pasig River almost takes the entire dry season.

The expected high water levels in the lake during the wet season have led to lakeshore diking system to protect the lakeshore communities.

Laguna Lake

Manila Bay

Metro Manila

CalirayaPump-

StorageSystem

Pasig-NapindanRiver

Mangahan Floodway

Effective Flood Control Operating System (EFCOS) Project of 1981‐1982.

EFCOS PROJECT (1981-1982) -Effective Flood Control Operation System including Telemetering and Flood Warning System in Pasig-Marikina-Laguna Lake Complex

Despite the construction of the Manggahan Floodway, the Rosario Weir, the Napindan Hydraulic Control Structure and the Napindan Channel (in 1980) which operated in an integrated and synchronized manner, it was not able to effectively relieve Metro Manila of the flood due to the inundations of the Pasig and high water level of the Laguna Lake.

In this connection, EFCOS Project study (Japanese funded) was conducted in 1981-1982 to establish an effective flood control system for the Manggahan Floodway and the Napindan Hydraulic Control Structure by means of telemetering and warning facilities.

Components of EFCOS PROJECT (1981-1982)

1. Hydrological Gauging Systems (Water Level and Rainfall Gauging Networks)

2. Telecommunications system (Overall arrangements, Multiplex Transmission and Telemetry Transmission Links and Warning System)

3. Structural Arrangements (Design and Construction of Necessary Buildings/Housings, Antenna Towers/Poles and Water Level Gauge Supports)

4. Institutional Arrangements (Jurisdiction of the Project, Organizational Structure, Evacuation Protocols)

Land use planning issue: villages and shopping malls built in river floodplains which is well within the river meander belt.

Marikina River and Rosario Weir as viewed looking downstream from Manalo Bridge. 

River constriction of a land reclamation for a housing development.

CirculoVerde Site

Manalo Bridge

Circulo Verde sign at this corner

Circulo Verde housing development  

THU BON RIVER SYSTEMTHU BON RIVER SYSTEMVIETNAMVIETNAM

Catchment Area: 10350 km2

Annual rainfall: 1960-4000 mmRainfall season: September to December

HydroMet Network

0200400600800

1000

1 3 5 7 9 11

mm

0200400600800

1000

1 3 5 7 9 11

0200400600800

1000

1 3 5 7 9 11

0

200

400

600

800

1000

1 3 5 7 9 11

0

200

400

600

800

1000

1 3 5 7 9 11

0100200300400500600700

1 3 5 7 9 11

mm

0100200300400500600700

1 3 5 7 9 11

mm

0

200

400

600

800

1000

1 3 5 7 9 11

mm

Rainfall distribution in the year at some stations

Annual rainfall Map

Big floods in Thu Bon basin cause of:Tropical storms or tropical depressions landing in combination with cold air surge; Inter-Tropical Convergence Zone (ITCZ) in combination with cold air surge and tropical depression.

When typhoon landing the northern part of the basin or directly to the basin, may cause big flood / inundation. Due to the affect of coastal line and topography, before landfall, typhoon often moves along the coast and causes rains over the basin.

Due to heavy rains that concentrate in a narrow and sloppy area, Thu Bon river has much bigger run-off volume in comparison to the almost all rivers in the North Viet Nam.

The maximum annual discharge is often very high, water concentrates quickly in small and sloppy part of basin in upper stream, runs down very quickly to narrow, flat and populated down stream (because there is not middle stream) and often causes dangerous inundation.

Flood Features in Thu Bon basin

Telephoned- Rainfall & Water level Stations

served for Flood forecasting

Communicating observed data to Central Hydro-Meteorological forecasting center and Regional Hydro-Meteorological Center

From: September to December

Flood Forecasting Alternatives in operation of ThuBon basin

• WLAi Nghia=f(WLThanh My• WLAi Nghia +f(Avg rainfall on

basin (Waring time 12 h)• WLCamLe =f(AiNghia)• WLGiao Thuy =f(WL Nong Son,

HiepDuc• WLCauLau=f(WL GiaoThuy)• WLHoiAn=f(WL CauLau)

Background forecast

Central Hydro-Met. Forecasting

Center

• Daily, medium- and long-term weather forecasts.• Flood forecast• Forecasts of heavy rain, cold surge, hot and dry weather.• Warnings of severe weather phenomena.

Regional Hydro-

Met. CenterWeather and hydrological short- and long-term forecasts for a region

Forecasts

Provincial Hydro-Met. Center

Weather and hydrological short- and long-term forecasts for a province.

Forecasting system

Mid CentralCenter

Quang Nam

Hydro-Met.

Center

ISOHYET

In storm 1-9 Nov 1999

ISOHYET of historical flood in 1999

Hydrograph at stations of historical flood in 1999

HuÕ

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

(c m)

Phó èc

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

(cm)

¸ i NghÜa

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

1 1 0 0

(cm) C©u L©u

0

100

200

300

400

500

600

(cm)

Simulate Inundation map Flood in 1999

Applied DHM model (2D)

Application of models for Thu Bon Basin

Soil Map

Land use Map

Topo Map

Thµnh MüS«ng Bung

S«ng K«n

1

23 4

5

S«ng Tóy Loan

N«ng S¬n

6

7

8Ly Ly

Schematization for Hydrodynamic model

Models have not been applied for operational forecasting. The tools used for flood forecasting are not updated.

The forecasting time for maximum WL is only 12-24 hours.

The warning time is only 24-36 hours, but not high confident because of rainfall prediction

Especially, River flow are regulated by reservoirs on upstream. It is necessary applying models to forecast.

There have not been any models applied for inundation forecasting in downstream.

Problems and Issues of FFWS in Vietnam

The problems to be improvedEnrichment of data sources (quantity, quality, in time) for

weather, hydrological forecasts and warningsConsolidating and upgrading observation network to meet

requirement of storm and flood forecasting and warning activities;Updating observation technology;Upgrading the calibration facilitiesStrengthening hydro-met. survey capabilities

Development of hydro-meteorological forecasting system Developing telecommunication system and material-technical base for forecasting activities;Developing forecasting technologies;Improving forecast system

Improvement of meteorological, hydrological, environment data collection, processing, archives and service systemImproving the management system of meterological and hydrological data to meet increasing needs of socio-economic activities, sientific research, etc.Strengthening the material technical base for hydro-meteorological documentation.

Research and Development will be focusing on:Improvement of forecast capabilities Improvement of telecommunication facilitiesInterpretation of satellite and radar imagesFamiliarizing and mastering new observation equipment and technologies

The problems to be improved