Regional Office for Asia and the Pacific

Southeast Asia Flood Update

21 October 2011

Bangkok/Rome, 21 Oct 2011 -- Localized flooding due to typhoons and heavy rains have affected large numbers of people and caused crop damage particularly in areas of the Mekong river basin.

Intense monsoon rains, typhoons and tropical storms in September and the first-half of October have caused significant localized flooding and devastation across Southeast Asia, including Cambodia, LAO People’s Democratic Republic, the Philippines, Thailand and Viet Nam, hitting areas across the Mekong river basin the hardest.

The recent floods, adding to the localized inundation from heavy rains since mid-July in some parts, have caused loss of hundreds of lives, displacement of millions of people and severe damage to housing, infrastructure and agriculture. The floods occurred when the current main wet season cereal crops were in the field, with paddy rice at the initial to mid growing stage, and maize at an advance critical flowering stage.

Damage to crops

The flooding has damaged standing crops, particularly paddy fields in low lying areas. Although no precise figures are yet available, the official estimates put damages to standing crops at 1.6 million hectares (or 12.5 percent of total national cropped area) in Thailand, 420 337 hectares (or 6 percent of the total national cropped area) in the Philippines, 332 634 hectares (or 12 percent of the total area under paddy) in Cambodia, 64 000 hectares (or 7.5 percent of the total area under paddy) in Lao PDR and 28 813 hectares (or 0.4 percent) in Viet Nam. In addition, loss of livestock and poultry is reported and significant numbers are considered to be at risk.

Although flood waters have started to recede in some areas, there are concerns of serious food shortages in the affected communities due to the difficulties in delivering food assistance. The abundant rain in surrounding areas, however, is likely to have beneficial effects on the growing crops.

The net effect on the national crop production would need to be assessed later in the season. FAO/GIEWS will continue to closely monitor the situation.

A brief situation summary by country is provided below.


Seasonal South-west monsoon rains increased significantly during September and were further intensified by the tropical storm Nalgae in early October, causing severe flash flooding in the Northeast, East and Central regions of the country.

The Department of Disaster Prevention and Mitigation estimated that 60 out of 77 provinces were affected in some way by the floods. Flood waters have inundated more than two-thirds of the country causing loss of life, the submergence of rice fields, loss of crop and livestock, closure of hundreds of factories and severe damage to buildings and infrastructure. Official estimates indicate that, as of 14 October, the floods affected over 2.4 million people and damaged at least 1.6 million hectares of standing crops.

The affected area covers 12.5 percent of the total national cropped land. Although no precise crop damage estimates are yet available, the main rice season at the critical growth stage is likely to be affected the most.

According to the Ministry of Agriculture and Cooperatives, nearly 9.9 million heads of livestock are at risk. It is expected that this estimate will rise in the central plains as the flood waters are topped by water discharges from major dams which are beyond or almost at full capacity.

The Philippines

The country was hit by typhoon Nesat on 27 September affecting 35 provinces in northern and centralLuzonand later by typhoon Nalgae on 1 October. This exacerbated the situation in 17 of the 35 provinces in the same region, the most affected being Nueva Ecija, Bulacan, Pampanga and Tarlac.

Both the typhoons and subsequent localized floods had a severe impact on the paddy production of the main 2011 season, which accounts for approximately 55 percent of the national rice output.

Preliminary official reports indicate substantial damage to 420 337 hectares with losses estimated at about 728 379 tonnes of paddy or 16 percent of the national production. Overall, latest estimates indicate that about 4 million people have been affected and at least 485 000 hectares of standing crops, including rice, maize and high value commercial crops (HVCC) have been damaged or lost to the floods. The affected cropped area covers 6 percent of the total national cropped area. Additionally, nearly 3.3 million livestock and poultry have been affected.


Since mid-August, the Mekong andTonle Saprivers have been overflowing, leading to severe floods in the southwest and northern regions of the country.

Official estimates, as of 14 October, indicate that 1.2 million people have been adversely affected and thousands of houses have been destroyed or damaged by flooding.

Preliminary estimates from the Ministry of Agriculture, Forestry and Fisheries indicate that 332 634 hectares of rice fields have been affected including at least 158 447 hectares of the crop damaged from the current main wet season, which accounts for about 80 percent of the annual national production.

Prior to the floods, the 2011 aggregate paddy production (wet and dry seasons) was forecast at yet another record level of 8.9 million tonnes, some 7.2 percent above the bumper crop the year before.

LAO People’s Democratic Republic

Typhoon Haima struck the northern and central provinces on 24 June with typhoon Nock-Ten hitting central and southern areas on 30 and 31 July, which caused severe flooding in Xayaboury, Xiengkhuang, Vientiane and Bolikhamxay provinces, affecting over 37 thousand people and destroying at least 7 200 hectares of paddy, maize, vegetables, cash crops and fruit trees. In addition, a total of 48.3 tonnes of rice seeds and household rice stocks were lost to the floods.

Official estimates indicate that nearly 430 000 people have been affected and at least 64 000 hectares of rice fields have been damaged since the end of June. However, a detailed assessment of the crop losses is not yet available. Some areas that were affected by floods in June-July were replanted.

Viet Nam

The mid-October heavy rains worsened the flooding situation in the central region of the country. Some 330 000 people have been affected, with 46 lives lost to floods since the beginning of the monsoon season in July. A total of 28 813 hectares of standing paddy crop have been damaged.

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