the mrc mekong flood forecasting and mrc flash flood … · 2010-06-23 · mekong river commission...

MEKONG RIVER COMMISSION

NGUYEN TIEN KIEN

Regional Flood Management and Mitigation Centre

Phnom Penh, Cambodia

The MRC Mekong Flood Forecasting

and

MRC Flash Flood Guidance Systems

International Training Programme 2010 - Management of Flood Control and Disaster Mitigation

China, June17—30, 2010

Outline

1. Operational data for flood forecasting in the RFMMC

2. MRC River Flood Forecasting System

2.1 Unified River Basin Simulation model

2.2 ISIS Hydrodynamic model

2.3 Delft - FEWS

3. MRC Flood Guidance System

4. Conclusions and Individual Plans




1. Operational data for flood forecasting

in the RFMMC





• Daily Satellite Rainfall Estimates (SRE)

and Numerical Weather Prediction (NWP)

gridded data

• Daily rainfall manual data from 131

stations (as of May 2009)

• Water level manual data from 49 stations

(12-hrly and daily)

• AHNIP telemetry data (hourly) from 20

stations

• HYCOS telemetry data (15 min) from 34

stations

• GTS rainfall data from 112 synoptic

stations coving the entire Mekong River

Basin

Data Availability

• Daily receiving of hydro-meteorological data from the four riparian

countries:

- telemetry system

- SMS (manual) data

through a software package : HydMet management software

• The HydMet is the primary database management system by

which rainfall and water levels observations are collected from the

riparian countries and collected for use within the new flood

forecasting system.

• The HydMet is installed in the main national line agencies of the

MRC Member Countries and the RFMMC.




2. MRC River Flood Forecasting System

(MRCFFS)



URBS

ISIS

Delft – FEWS



22 Stations in the mainstream1. Chiang Saen

2. Luang Prabang

3. Chiang Khan

4. Vientiane

5. Nong Khai

6. Paksane

7. Nakhon Phanom

8. Thakhek

9. Mukdahan

10. Savannakhet

11. Khong Chiam

12. Pakse

UR

BS

ISIS

+ R

eg

ress

ion

13. Stung Treng

14. Kratie

15. Kampong Cham

16. Phnom Penh Bassac

17. Phnom Penh Port

18. Prek Kdam

19. Koh Khel

20. Neak Leung

21. Tan Chau

22. Chau Doc



Unified River Basin Simulator (URBS)

• Semi-distributed non-linear hydrologic network model

• Ability to model spatial & temporal variability of rainfall

• Specifically tailored for flood forecasting

• Combines:

- rainfall-runoff model

- runoff-routing model

1

23

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

21

22 20

23

24

25

26



URBS (con’t)

• 52 URBS models, covering > 740,000 km2

and represented by over 2,217 sub-

catchments, were developed and calibrated:

- 49 runoff routing models are linked together

- 3 channel routing models:

Chiang Saen to Kratie

Tonle Sap system

Kratie to Tan Chau/Chau Doc.



ISIS Hydrodynamic Model• ISIS is a generic 1D model for the

simulation of unsteady flow in channel

networks.

• The ISIS model within the FFS starts at

Stung Treng to the South China Sea,

including the Tonle Sap Lake and

Floodplain, the Cambodian floodplains

and the Vietnamese Mekong Delta.

• The extent of downstream boundaries of

the model are at the mouths of the

Mekong (and the West Sea).

• Tributary inflows supplied to the model

are obtained from the URBS.



Delft-FEWS

• as a data management and modeling platform.

• FEWS collates rainfall and water level inputs, runs the set of URBS models, manages the model results and publishes the flood forecasts.

• FEWS Stand alone system : data in the database is not shared with others, but whole database can be copied

• FEWS Client-serve (on-line) system:

- central location to do the calculations and to store the data

- users in different offices are connected via RFFMC network,

synchronising with the central database when they need data



China_MRCFFS.mpg


3. MRC Flash Flood Guidance System

(MRCFFG)



• The MRCFFG system has been developed by the U.S. Hydrologic Research Center (HRC) through a program funded by the U.S. Agency for International Development (USAID) - Office of US Foreign Disaster Assistance (OFDA). Completely set up and installed at the RFMMC in early September, 2009.

• The MRCFFG is designed to provide flash flood guidanceinformation on a small basin scale across the four riparian countries MRC.

• The primary mission of the MRCFFG system is to provide real-time informational guidance products pertaining to the imminence of potential small-scale flash flooding throughout the region of application.

Background



• MRCFFGs is a diagnostic system for flash floods to produce

forecasts and ultimately warnings for flash floods.

It is not a predictive system

• The system provides warnings for flash floods from intense

rainfall events through the use of satellite and gauge-based

rainfall estimates.

• A user-friendly interface provides quantitative real-time

diagnostic information that may be used by the forecaster in conjunction with other local forecast information.

MRCFFG System



MRCFFG System Design OverviewThe RFMMC receives data

from 4 riparian countries

The products are provided to dedicated national

agencies on the Dissemination Server

These data together with Satellite rainfall data

are processed inside the Computational Server

Various models are applied



• to provide organized and convenient access to downloadable

data products for local acquisition

• to facilitate preliminary product review in order to focus

forecaster attention on urgent points of interest relating to

potential flash flooding

• to facilitate the quality control and operational management

efforts of forecasters and system administrators

MRCFFG Dissemination Server User Interface

MRCFFG Operational Output Products



Hydroestimator satellite precipitation,

un-biased corrected rainfall for 1, 3, 6, and

24 hour accumulations

HE

Mean areal precipitation for each basin for

1, 3, 6, and 24 hour accumulations based on

bias-corrected satellite rainfall estimates

MAP

Average Soil Moisture

(ASM)

• Soil water saturation fraction for the upper zone of the Sacramento Soil Moisture Model for each of the MRCFFG sub-basins.

• Updated every 6 hours at 00, 06, 12 and 18 UTC.



the amount of rainfall of a

given duration (1 – 6 hours)

over a small basin needed to

create minor flooding

(bankfull) conditions at the

outlet of the basin.

Flash Flood Guidance

(FFG)

the amount of rainfall of a

given duration in excess of

the corresponding FFG

value.

The FFT, when used with

existing or forecast rainfall,

is an index that provides an

indication of areas where

flooding is imminent or

occurring and where

immediate action is or will

be shortly needed.

Flash Flood Threat (FFT)

The system can detect the storm activity and

compute the change of soil moisture

The FFG can show potential

critical flash flooding

The system can identify FFT in

some areas

China_MRCFFGs.mpg


6. Conclusions and Individual Plans



Conclusions• The MRC Mekong FFS is user-friendly, flexible, robust in flood forecasting and

provides a platform for the incorporation of new models.

• The availability and quanlity of both hydrological and meteorological (rainfall) data as inputs for models are highest priority because of deciding factors for forecast result and accuracy.

• Facets of the models and modelling system need to require refinement.

• The RFMMC will maintain and operate the MRCFFG servers.

• Even though the both FFGCS and FFGDS servers are designed to be

fully automated, there will always remain a critical need for ongoing

observation and quality control.

• The RFMMC will be required to perform frequent observations of the MRCFFG system processing to ensure that the system’s automated features are working properly.



• Improvement of forecast rainfall by using data from different sources may

provide higher frequency and better accuracy.

• Improvement for model calibration by updating the rating curves and other

parameters at stations along the Mekong mainstream to be supported by

Line Agencies, especially at main forecast stations.

• Since the current system is capable in producing medium-term forecasts up

to 10 days, in advance, forecasts can be made available to a designated

national flood forecasting agencies for their internal uses.

• A second forecast cycle and product dissemination as appropriate during

critical flood conditions should be initiated which would provide valuable

additional information for Member Countries.

• Preparation for MRCFFG implementation during flood season 2010.

Individual Plans



THANK YOU VERY MUCH

FOR

YOUR ATTENTION

the mrc mekong flood forecasting and mrc flash flood … · 2010-06-23 · mekong river commission...

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