South-East Asia Flood Risk Reduction Forum

Transcription

1 UNITED NATIONS ECONOMIC AND SOCIAL COMMISSION FOR ASIA AND THE PACIFIC South-East Asia Flood Risk Reduction Forum 20 February 2012, Bangkok, Thailand By: TES Sopharith Senior Hydrologist Department of Hydrology and River Works, Cambodia

2 Contents Brief of river systems and flood characteristics in Cambodia; The 2011 flood damage The flood response by the Royal Government and International countries and Agencies. Flood monitoring by the DHRW, MOWRAM. Gaps, Challenges and efforts

3 River Systems: 500 km of Mekong River bisects Cambodia. Tonle Sap Great Lake is connected to the Mekong river by the Tonle Sap river at Chaktomuk junction in Phnom Penh, some 120 km to southwest of the outlet of the Lake. At Phnom Penh - Chaktomuk junction, after meeting the Tonle Sap river, the Mekong then splits into two rivers namely the lower Mekong and the Bassac rivers. Both rivers flow parallelly and discharge into the South China Sea. About 86% of Cambodia s territory is the basin of the Mekong, the Bassac and the Tonle Sap rivers and the Tonle Sap Great Lake with its tributaries 3

4 Flooding in Cambodia Two main types of floods can be identified: Mekong flood which caused by cumulative of rainfall in the upper catchments throughout the rainy season and most severe floods are the results of tropical storms and tropical depression. The Mekong flood is slowly but steady built in rising level. Flash Flood: The flash flood mostly occurs in the mountainous areas with high rainfall intensity and affected by Typhoon or storm in the region. those floods are swift and could last only for a few days but often caused severe damage to crops and infrastructure especially for tributaries around the Great Lake and eastern tributaries of the Mekong. 4

5 2011 Flood A series of heavy monsoon rains caused by tropical storms and low pressure combined to make 2011 the worst flood season in Cambodia since It was as a combination of Flash flood + the Mekong flood. The flood started on 8/10/2011 and ended on 11/15/2011, with a duration of 98 days. Source: NASA on October 18, 2011 Source: Weather Chart issued at 12:00 UTC on September 23, 2011 by Thai Meteorological Department

6 Comparison between 2000 (white)and 2011 (light blue)max. flood extent in Cambodia and Viet Nam Max. flood extent Year 2011 smaller than max. flood extent Year 2000, especially in Viet Nam

7 2011 Flood: Impact on Social Based on official statistics issued by NCDM on 3 Nov 2011: hit many parts of 18 cities and provinces (Kampong Thom, Battambang, BanteayMeanchey, and SiemReap, home to marvelous Angkor Wat, are the most affected); Dead 250; 1,593,976 persons of 354,217 families affected; More than 23,000 families evacuated to higher ground. 268,631 houses flooded, and 1297 houses were swept away ; 491 pagodas, 115 health centers and 1360 schools were submerged in the floods;

8 2011 Flood: impact on Agricultural production Submerged 432,020 ha of grown rice paddies, 66 % of which were destroyed; Submerged other crops of 21,929 ha; 1675 animals dead.

9 2011 Flood: Impact on Infrastructures National and provincial roads: 922 km. Rural roads: 4,400 km Bridges Inundated: 177 locations Irrigation dams submerged: 496,745 m River bank collapsed: 11,789 m

10 2011 Flood response On 22 September 2011, the Prime Minister, Samdech Techo Hun Sen called and ordered the responsive agencies, such as National Committee for Disaster Management, Cambodian Red Cross, to take proper mitigating measures for rescuing the flood victims. Cambodia's Council of Ministers held a special meeting on 26 th September 2011 to take measures dealing with the Mekong River and flash floods inundating most parts of the country.

11 Government, Several humanitarian organizations and international donor organizations were assessing the situation in flooded areas and were beginning distributing of food and non food items to affected population. There is an immediate need for shelter, food and safe drinking water as well as education for safety.

12 Aid to flood relief in Cambodia The government had set aside more than $100 million to help repair damages. Besides, Cambodia,till 3 November 2011, received Besides, Cambodia,till 3 November 2011, received humanitarian aids from various international organizations and countries, such as, ADB, UNDP, WFP, FAO, Singapore Red Cross, ASEAN, Japan, China, Republic of Korea, Thailand, Vietnam, Myanmar, France, Australia and USA.

13 Flood monitoring Flood levels along the Mekong, TonleSap and Bassacmainstreams are monitored by the Department of Hydrology and River Works (DHRW) of the Ministry of Water Resources and Meteorology (MOWRAM). All flood monitoring and forecasts are daily distributed to the government institutions, Prime Minister office, line agencies, NGO and other organizations and mass media. In case of severe flooding, warning is also issued by the Minister to the abovementioned receivers. Flood level monitoring on the Mekong mainstream in Cambodia is also put in the DHRW website:

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15 2011 Maximum flood levels on the Mekong mainstreams Station Warning level Date Flooded Flood level 1 Stung Treng Sep Kratie Sep Kampong Cham Sep Chaktomuk Sep Nak loeung Sep Koh Khel Sep Prek Kdam Sep

16 Flash Flood Detection System Under support of the MRC, the DHRW can access the MRCFFG system, developed by the U.S. Hydrologic Research Center (HRC) through a USAID/OFDA funded program, to obtain real-time informationon flash flood guidance (FFG), flash flood thread (FFT), mean areal precipitation (MAP) andaverage soil moisture (ASM) occur for 1, 3, 6, and 24 hour on a small basin scale across the country. However, in 2011 we just used this FFGS as trial and haven t applied this information for Warning yet. The MRCFFG is a diagnostic system for flash floods to produce forecasts and ultimately warnings for flash floods. It is not a predictive system.

17 Example: flash flood in SiemReap on 22 September :00 UTC The flash flood occurred in some areas in SiemReap city at noon time was detected by MRCFFG. The 24-h observed rainfall was about 200 mm 250 Daily rainfall at Banteay Srey(1 August to 1 November 2011) Aug 4-Aug 7-Aug 10-Aug 13-Aug 16-Aug 19-Aug 22-Aug 25-Aug 28-Aug 31-Aug 3-Sep 6-Sep 9-Sep 12-Sep 15-Sep 18-Sep 21-Sep 24-Sep 27-Sep 30-Sep 3-Oct 6-Oct 9-Oct 12-Oct 15-Oct 18-Oct 21-Oct 24-Oct 27-Oct 30-Oct m 0 Banteay Srey date 24-h accumulated rainfall by hydroestimator

18 Flooding in Siem Reap, Sep 2011

19 Gaps, Challenges and efforts So far only flood information on the Mekong mainstream is monitored. The accuracy of short-term forecast of these flood levels are acceptable. Sometimes flood information could not reach to the remote and rural people who live in the flood vulnerable area. This caused loss of many lives, especially children. Monitoring of flash flood is still not efficiently and is relied on the MRCFFG. Moreover, an accuracy of flash flood forecasting model need to be improved. To improve the issue, this year, the MOWRAM will install a Doppler Radar, which will be completed before May 2012 Besides, through a series of trainings on space technology application for flood risk reduction provided by ESCAP, ICHARM and JAXA we expect to be capable to make use of the JAXA reliable satellite information for flood risk reduction in our country.

20 Doppler Radar system This dopplerradais build in the MOWRAM head quarter. Provides real time rainfall cover area with diameter of 400 km. Synergy product ARP05 for short-term and longterm forecasts Meteo-factory for issuing warning

21 Thank you for your kind attention!