WRD/PTC.35/Doc. 3 (2), p. 4
WORLD METEOROLOGICAL ORGANIZATION FOR PARTICIPANTS ONLY
AND
ECONOMIC AND SOCIAL COMMISSION WRD/PTC.35/Doc. 3 (2)
FOR ASIA AND THE PACIFIC (23.IV.2008)
______
WMO/ESCAP Panel on Tropical Cyclones
Thirty-fifth session
Manama, Bahrain
5 to 9 May 2008 ENGLISH ONLY
Review of the 2007 cyclone season
Country Report – Thailand
1. NARRATIVE ACCOUNTS OF TROPICAL CYCLONES IN 2007
During 1st November 2006 to 31st October 2007, Thailand area responsibility, 0°- 25° N and 90°-120°E, experienced 1 tropical cyclone which developed in the Bay of Bengal and intensified to tropical cyclone “AKASH” on 14th May 2007. It then moved in a northerly direction and made landfall near Chittagong, Bangladesh later that day. It weakened rapidly as it traveled further inland on 15th May 2007. Generally, “AKASH” had no effect on Thailand’s weather.
However there were 2 tropical cyclones originated in the West Pacific and the Gulf of Thailand that moved across southern Thailand to the Andaman Sea.
The first was typhoon “DURIAN” during the end of November 2006 to early December 2006. It first made landfall at the Philippines and continued its track towards the South China Sea. It weakened into the tropical storm on 4th December before moving to the southern tip of Vietnam on 5th December. This storm further moved into the Gulf of Thailand and gradually weakened to be a tropical depression before making another landfall over southern part of Thailand on 6th December. It continued to move to the Andaman Sea and finally downgraded into the low pressure cell on 8th December. DURIAN brought torrential rainfall and flash floods in the upper area of southern Thailand east coast and produced unseasonable rain in some areas of upper Thailand on 6th December.
The second was tropical depression (TD2) developed from the active low pressure cell in the Head Gulf of Thailand on 1st May 2007 and moved westward into Chumphon province on the same day. It continued to move to the Andaman Sea on the following day and turned northeastward towards Myanmar on 4th May. This tropical depression moved further inland and downgraded to the low pressure cell before covering the border of Thailand and Lao P.D.R. on 5th May and finally dissipated on 7th May. While TD2 moving through southern Thailand, it produced widespread rain with isolated heavy and very heavy rainfall in nationwide. Flash floods were experienced in southern Thailand east coast, Chumphon and Prachuap Khiri Khan Provinces. Moreover, TD2 also produced torrential rainfall across much of upper Thailand throughout the first week of May.
The tracks of tropical cyclones are shown in Fig.1.
Cause of Occurring / Affected Areas / Damages1. Durian Depression
(5 – 7 November 2006) / 5 Provinces namely Surat Thani Prachuapkhirikhan,Chumporn, Nakorn Shithumarat and Songkla / Durian brought heavy windstorm and flooding to the affected areas but no report of casualties. Schools were closed and travel by sea was prohibited
2. TD2
(1 – 2 May 2007) / 5 Provinces, 18 districts, 70 tambons, 264 villages, 29,179 affected, 7,817 families / About 560,164 US
3. AKASH
14 – 15 May 2007) / - / -
WRD/PTC.35/Doc. 3 (2), p. 4
2. METEOROLOGICAL COMPONENT
a. Improvement of facilities
+ To enhance data exchanges among the TC Members, the Bangkok - Singapore
GTS circuit has been upgraded from X.25, speed 9.6Kbps to the TCP/IP Frame
Relay with the speed of 16 Kbps (CIR), and Bangkok - Phnom Penh GTS circuit
has also been connected using VPN via internet.
+ To strengthen the Indian Ocean Tsunami Warning System, TMD in collaboration
with NOAA will deploy 2 more DART Buoys (Deep-ocean Assessment and
Reporting of Tsunami) in 2007-2008 after the first DART Buoy was installed in
December 2006. It will be a major milestone of the Tsunami warning system in
the region for all 27 Indian Ocean countries. The detected information and
Tsunami warning message will be disseminated via the GTS of TMD for all to
access.
+ Installed a new communication system to improve the stability and speed of
International data exchanges, and developed the Tsunami information check and
monitoring system from GTS.
+ To support Tsunami warning system, 9 tidal gauges will be added to the existing
9 tidal gauges deployed in the Andaman Sea along the coastal areas of Southern
Thailand. The installations are expected to complete by 2008. With the expanding
coverage of the tidal gauges, TMD assures that the tidal wave monitoring will
contribute beneficial information for the betterment of Tsunami warning in the
Indian Ocean region..
+ The tropical cyclones and other NWP forecasts from other forecasting centers such as RSMC Tokyo, ECMWF, IMD, KMA, and BOM have been taken in
considerations together with TMD’s NWP products for more forecasting accuracy,
in both medium and long range terms.
+ TMD has developed a website at Suvarnabhumi Airport to facilitate data users
(Air lines) to immediately access necessary data for the Take-off Condition, and
other data including TAFOR, SIGMET, and METAR.
+ Three C-band Doppler radars have been added to the existing 20 stations in the
TMD’s Radar Network in order to enhance the radar observation of the country
to closely monitor rainfall pattern, cloud movement, and its intensity in the
remote areas.
+ Replacing volunteer rainfall stations in northern Thailand with 110 automatic
raingauge stations, apart form the existing 161 automatic stations in the telemetring system of TMD. Data from the automatic stations will be incorporated into the existing telemetering network to strengthen flood monitoring and warning in the critical flood-risk areas of the country. Moreover, additional 820 stations will be incorporated into TMD’s automatic raingauge network by 2008.
+ Each TMD meteorological station will be equipped with an automatic station,
thus there will be additional 87 automatic stations in TMD meteorological
observation network by 2008.
+ The Vaisala Model RP20 will replace the Vaisala ’s retired model at 4 upper air
stations, the installations are expected to complete in 2008.
+ The improvement of observation for aviation by the deployment of 3 Automatic
Weather Observation System (AWOS) at 3 local airports of the country.
+To give warning messages to people promptly, 79 Disaster Warning Towers have been constructed in 6 provinces directly affected by the Tsunami as a result of the tragedies due to the 26 December 2004 Tsunami Event. However, to be able to cost-effectively use and cover all types of natural disasters, including torrential rain, flash floods, and landslide etc. apart from Tsunami and earthquake, TMD has constructed 48 more Warning Towers in the disasters prone areas of the country. Totally there are 127 multi-hazard Warning Towers in National Warning System of Thailand which will play the major role to deliver disaster warning to public more timely, and 144 more towers will be constructed by 2008.
b. Technical Advancement
+ The Virtual Wave 3D has been developed and implemented to incorporated oceanic wave related data and displayed wave/storm surge forecast dimensionly.
+ Newly designed main website of TMD, in both Thai language and English, has
been improved to incorporated more information of tropical cyclones, including
tracks, radar observations, satellite imageries and NWP products to be more
user-friendly warning tool.
3. HYDROLOGICAL COMPONENT
Hydrological Activities on November 2006-October 2007
Rainfall accumulation of Thailand from January 1, 2006 to November 5, 2006 was greater than the long period average record 11 %, especially to the northern part of Thailand the accumulated rainfall was greater than the average 29 %.
Normally the month of November is the end period of heavy rainfall under North Eastern Monsoon for the northern, central, eastern and the western part of the country. But due to the previous peak flood occurred during October 2006,some flooded area were still in Yom and Nan river basin for the upper Chao Phraya River Basin such in Phitsanuklok, Sukhothai, Phichit and U-Thai Thani province with flood depth 0.20-1.50 m.The flooded area for Lower Chao Phraya River Basin covered Singhaburi, Angthong, Ayuthaya, Pathumthani, Nonthaburi, Nakhonpathom, Suphranburi province and 4 regions of Bangkok Metropolitan with the maximum peak discharge at station C.2 Nakhonsawan province(confluence of Ping , Wang ,Yom and Nan River Basin) was 3,220 cms.(as its normal maximum capacity)
Flood management , Royal Irrigation Department installed 383 large pumps for flood depth reduction and also diverted the excess flood volume to the west and east side of Chao Phraya River 30-42 mcm./day and 15-22 mcm./day respectively and cooperated with the operation the Lad Pho Project (Royal Project) near the river mouth increased flood drain volume 45-49 mcm./day and estimated draining schedule will be completed by the end of December 2006 and completed as the plan.
During November 2006 – October 2007 there were many typhoons (TY), tropical storms (TS), tropical cyclone (TC) and depressions track passed near by the country, effective and non effective for rainfall increasing as follow :
- TY CIMARON, November 1-6, 2006 (no direct effected to Thailand)
- TS CHEBI, November 14-15, 2006 (increased heavy rainfall to Thailand)
- TY DURIAN, December 3-5, 2006 (no direct effect to Thailand)
- Depression, May 3-4, 2007 at Andaman Sea (increased heavy rainfall to
Thailand)
- TY YUTU, May 18-20, 2007 near Philippines (no direct effect to Thailand)
- Low pressure trough, May 30 - June 21, 2007 created heavy rainfall through
Norther- Eastern part of the country
- TC 03B, June 25-30, 2007 (create heavy rainfall to the west of the southern
of the country)
Flood monitoring, Royal Irrigation Department assigned one center “Water
Watch and Monitoring System for Warning Center” to collect data, process, analysis and report to the executive, TV, radio, newspaper, the governor and related government and public sector for water disaster forecast, alert and warning.
a. Improvement of facilities:
+ The Royal Irrigation Department (RID) installed the upper Chao Phraya
telemetering projects in the Chao Phraya river basin to link with the lower part
that started from Ayuthaya province down to the gulf of Thailand. The real-time
in situ and remotely sensed data collection is on hourly basis.
+ Department of Water Resources (DWR) has cooperation with Mekong River
Commission Secretariat (MRCS) and other Mekong River Country (Lao’s PDR,
Cambodia and Vietnam) to improve the hydro-meteorological monitoring network
In Mekong Mainstream under the Appropriate Hydrological Network Improvement Project (AHNIP), Basin development plan, Water utilization program, Environment program, Flood mitigation management program and drought management program, Mekong HYCOS and start up integrated knowledge management program.
+ Department of Water Resources as the National Committee of Thailand for the
International Hydrology Program (IHP) held the 14th meeting of Regional Steering Committee at Bangkok, Thailand. Moreover, we support the proposal framework for IHP-VII and prepare the Catalog River of Bangpakong basin.
Some specific highlighted issues are as follows;
- Methodologies for integrated river basin management.
- Promotion of public awareness rising on water management.
- Institutional development and networking for WET.
- Guidelines on the sustainable and integrated water management with
due consideration to public’s living quality and participation.
- Increasing the available sources water by improving both existing
Natural and man-made sources.
- Flood and drought management
b. Technical Advancement:
+ The small telemetering system (not included existing large telemetering system)
especially for rainfall data collection in ungauged area were equipped and moved
those stations along the pressure trough for more accurate rainfall data. The use
of weather radar, satellite imageries from web-site near real time were one of the
most important tool for flood management, preparednes, prevention,
rehabilitation and planning such as Global Satellite Mapping of Precipitation
(GSMap), Global Flood Alert System (GFAS), Sentinel Asia Disaster
Management, flood monitoring and Asia Pacific Space Agency Forum
(APRSAF).
+ For 13 existing large scale telemetering system,this year 2008 there is some
change of the policy, firstly for system maintenance due to less capacity building.
Royal Irrigation Department has decided to let the consultant firm take in charge
on maintenance the system and provide the data as RID requested. Secondly,
RID.has the plan to select only one of the best suitable model for flood work
which the operators have more experience and skillation to solve the problem of
different model and operator transfering.
+ At this moment, RID disseminated the forecasted results and warning to the
concerned agency via internet, radios and televisions.
+ At present, Department of Water Resources has cooperation with Mekong River
Commission Secretariat in the hydro-meteorological monitoring network in
Mekong Mainstream and linkage hydrological data (automatic water level).
+ RID expanded area of coverage in case of Chao Phraya river basin by installing the upper Chao Phraya telemetering system to strengthen the forecasting results in
Chao Phraya river basin which is the largest basin in Thailand.
+ Department of Water Resources (DWR) has developed and improved in the
hydrological and meteorological monitoring network in Bangpakong river basin and
Prachup Khirikhan, located at Eastern of Thailand for water resource management,
including flood forecasting and management. Moreover, telemetering hydro-
meteorological stations was established in Mun and Chi river basin for flood
forecasting and management. This project aimed to set up the hydro- meteorological stations network and early warning system.
+ Department of Water Resources (DWR) has been setting up Early Warning System
since 2005. At present, it continues to develop and set up a flood and landslide
warning system in mountain and upland area cover 53 risky villages, dealing with
system alerts activated heavy rainfall and rising of river levels tomonitor at
appropriated site. Early warning signal were sent in advance to subscribers and
communities in real time of the impact of disasters, provided time for people to take
response actions.
+ Improving the hydrological database system for water resources management,
planning, construction, and maintenance of hydraulic structures and for scientific
research, called HYDRO WEBBASE which established at Department of Water
Resources (DWR) and continued for more effectives useful.