International Workshop on Flash Floods Forecasting 13-17 March 2006, San Jose, Costa Rica

Development of Equipment for Community Flash Flood Warning in the Caribbean and the Central

America

Hidetomi Oi Japan International Cooperation Agenc

y (JICA)

Jacob Opadeyi West Indies University in Trinidad and Tobago

History of development of equipment

• After hurricane Mitch in 1998, a person of CEPREDENAC invented a water level gauge: cheap and simple but much more functional than the conventional stuff gauge. Many communities in Central America have now warning system using this equipment.

• In 2003 the equipment was presented at a conference in Jamaica. A participant from CDERA thought rain gauge should also be improved applying the same concept.

• In 2004 a new type of rain gauge was manufactured in Japan and was donated to a community project in the Philippines.

• In 2005, improvement was made with the equipment (increase in the number of sensors from 1 to 3). The improved one was installed in a community in Barbados.

• In 2006, a group of engineers of UWI volunteered to make further improvement (automatic dialing to residents). The new one will be used for community projects in CDERA member states to start in 2006.

• Mass production is necessary to cover so many communities at risk of floods, while continuing effort for improvement. Problem is lack of fund.

THE CARIBBEAN

BARBADOS

TRINIDAD & TOBAGO

COSTA RICA

What is new? What are advantages ? What are limitations?

Answers will be given by the following examples.

Reventado Caparo Speightstown

Community Flood Warning for Reventado in Costa Rica

- Example of using the new water level gauge -

Rio reventado

Taras, Los DiquesAfectado x avalancha

1964

Cartago. Reventado watershed. A big avalanche in 1964 　 related with volcanic deposits and different materials (ash & piroclast) combined with heavy rains.

Costa Rica. Effects by avalanches. Area Reventado Watersheds and Los Diques Communities.

Installation of water level gauge

Costa Rica

ADVANTAGES

Cheap, easy O/M

Heavy rain is monitored even if it occurs in the midnight.

Presently, the gauge readers have to remain stand-by when alerted by weather forecast of possible heavy rainfall. But with this equipment, they are free until alarmed by buzzer/lamp.

Community Flood Warning for Speightstown in Barbados

- Example of using the new rain gauge -

Barbados Meteorological Services (BMS) Flood Warning

7:00 am Monday, November 22, 2004

Here is a Flood Warning from BMS.

A persistent trough that has been in the area for the last few days produced moderate to heavy showers during the night.

These conditions are expected to persist over the island today and with the saturated conditions of the ground any additional rain is likely to produce flooding in some areas.

Residents in flood prone areas should be on the alert and take the necessary precautions.

This warning will remain in effect until 4 pm today.

Rainfall Equipment with Alarming Unit

10

20

30

40

50

30㎜

POWER

ALARM BOX

Rain Receiver

Conduit pipe

Built in electrode

Alarming unit

Cable

Buzzer

Water tank

Scale

４

Rainfall equipment with the alarm unit for community operated flood warning

Fixed or Mobile Phone

　　

　　　

Whenever accumulated rain reaches pre-set

levels, then,

The buzzer sounds and the

light turns on, and dials residents at

the same time

Conceptual System Design

Features of the System

Dept.　of　Surveying　and　Land　Administration　The　University　of　the　West　Indies,　Trinidad

Jacob　Opadeyi,　PhDJacob　Opadeyi,　PhD

• The system is capable of detecting 3 predefined rainfall levels.

• The device generates an audible alarm based upon the changing rainwater levels.

• The electronic of the system transmit alarm signals to a public or cell telephone using either landline or GSM network.

• It is a stand alone system.

Features of the System

Dept.　of　Surveying　and　Land　Administration　The　University　of　the　West　Indies,　Trinidad

Jacob　Opadeyi,　PhDJacob　Opadeyi,　PhD

• When it rains, rainwater drips into the cylindrical container through the funnel place outside of the monitoring station.

• When the rainwater reaches any of the three pre-determined level, the system will self-dial a call to a phone to the alarm level using 3 different rates of tones.

• The system will dial a user-configured number within 6 seconds of any new level being crossed.

Features of the System

Dept.　of　Surveying　and　Land　Administration　The　University　of　the　West　Indies,　Trinidad

Jacob　Opadeyi,　PhDJacob　Opadeyi,　PhD

• The unit will output a unique level-dependent audible beep pattern approximately 2 minutes after any level has been exceeded. The unit remains silent otherwise.

• Calls are repeated every 5 mins• The unit identifies itself using

caller-ID. • The phone number is stored in

non-volatile system memory.• Currently operates ONLY with

115V AC.

System Requirements

Dept.　of　Surveying　and　Land　Administration　The　University　of　the　West　Indies,　Trinidad

Jacob　Opadeyi,　PhDJacob　Opadeyi,　PhD

1.The device should be installed on a house or a remote monitoring station.

2.The station should have a direct phone line to be used for initiating calls

3.The station should be wired with 110V electric power with outlet for the system

4.The landline or cell phone capable of receiving calls 24/7 within the territory

Flood Hazard Map of Speightstown, Barbados

ADVANTAGES

Cheap, easy O/M;Sudden rise in water level can be

detected even if it occurs in the midnight;Gauge readers no more need to go out to

the gauging sites under the risky condition of wind storm, in the midnight etc.

Community Flood Warning for Caparo in Trinidad and Tobago

- Introduction of the new water level gauge is under consideration-

EX. OF COMMUNITY OPERATED FLOOD WARNING

2 year flood

5 year flood

10 year flood 50 year flood

Caparo river, Trinidad

Stuff gauge for community flood warning

Problem: Difficult to go to the sites under heavy rainfall and strong wind

Advanced Systems

Recommendation (1)

• WMO will support national/regional institutes to produce/improve equipment for community flood warning and to test/evaluate the appropriateness to different conditions, and will officially announce the result.

Recommendation (2)

• WMO, NOAA and other leading agencies will take actions for the more closer cooperation between:

- meteorologists, hydrologists and disaster managers - all levels, central level through community level.

• Representatives from all levels will be invited to this kind of meetings in the future.

• Manuals, guidelines etc. will be prepared to cover not only advanced technologies but also primitive ones so that governments and local groups may chose whatever most appropriate to their respective conditions, natural, social, human, financial etc.

• In conclusion, in order to attain the goal (protect lives and properties) community based flood warning should be promoted while continuing effort for the advancement of high-technology and its application.

Thanks

For further information please contact:

Oi.Hidetomi@jica.go.jp

jopadeyi@eng.uwi.tt