Flooding in Southeast Asia 2011 : 2554 มหาอุทกภัยแห่งเอเชียตะวันออกเฉียงใต้

Thailand and Cambodia continued to cope with widespread flooding at the beginning of November 2011. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured the top image on November 1, 2011. For comparison, the bottom image shows the same area three years earlier, on November 12, 2008.

These images use a combination of visible and infrared light to better distinguish between water and land. Water ranges in color from electric blue to navy. Vegetation is green. Bare ground and urban areas are earth-toned. Clouds are pale blue-green.

Barely discernible in 2008, Thailand’s Chao Phraya River and its tributaries have spilled onto floodplains in 2011. Meanwhile, in neighboring Cambodia, Tônlé Sab (Tonle Sap) and the Mekong River have soaked normally dry land. Rivers are also visibly swollen in eastern Thailand.

Flooding plagued much of Southeast Asia in the 2011 monsoon season. Thailand, Cambodia, Burma (Myanmar), Vietnam, Laos, and the Philippines—which experienced heavy rainfall from intense tropical storms—suffered a collective death toll of more than 1,000, according to The Diplomat. More than 400 people had drowned in Thailand, and 250 people had perished in Cambodia. Besides the human toll, the floods swamped agricultural land. The United Nations warned that the inundated fields raised the possibility of food shortages.

By November 1, Voice of America reported, many communities in Thailand had spent weeks under a meter (3 feet) or more of water, and floods had affected two-thirds of the country’s provinces. The threat of floods in Bangkok was growing. At the beginning of November, Bangkok Post reported, all 50 districts of the capital city were at risk of flooding. The Chao Phraya River flows through the city to the Gulf of Thailand, but high tides from the sea had pushed water up the river for three days, just when high water from floods threatened to overwhelm city canals.

Across the border, flood waters had transformed northeastern Cambodia into “a vast inland sea,” The Guardian reported. Stagnant water, and residents forced to live in close quarters with livestock, contributed to the disease toll. Dengue fever was on the rise, and doctors had diagnosed the first cases of cholera.


  1. Bangkok Post. (2011, November 1). All districts in Bangkok still “at risk.” Accessed November 1, 2011.
  2. Corben, R. (2011, November 1). As floods drag on in Thailand, displaced grow restless. Voice of America News. Accessed November 1, 2011.
  3. Hunt, L. (2011, November 2 [local time]). Asia counts flood costs. The Diplomat. Accessed November 1, 2011.
  4. Tran, M. (2011, November 1). Cambodia floods bring mounting disease toll. The Guardian. Accessed November 1, 2011.

NASA images courtesy MODIS Rapid Response Team, Goddard Space Flight Center. Caption by Michon Scott.

Instrument: Terra – MODIS

Flood Waters Inundate a Bangkok Airport – น้ำท่วมสนามบินดอนเมือง

It would be easy to assume, at first glance, that the watery rectangle in the center of this image is a harbor. Narrow structures extend into the blue water like docks; small white dots break up field of blue like ships on water; and the structures lining the area resemble large warehouses.

But on closer inspection, it becomes clear that the white dots are airplanes, and that the watery rectangle is the submerged runway complex of the Don Muang Airport. Located north of downtown Bangkok, the airport is in one of 31 districts affected by flooding in the Thai capital. All 50 districts remain under threat, according to local officials.

The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite took this image of Bangkok on October 29, 2011. Flooding is most obvious at the airport, but much of the area in the image is flooded. The spaces between buildings and under trees are blue. Signs of flooding are also evident throughout the large image, which includes a much wider area.

The floods started in late July as unusually heavy monsoon rains and a tropical cyclone inundated Thailand. Floods swelled rivers and filled reservoirs throughout the country. By late October, the floods reached Bangkok through the Chao Phraya River and numerous canals and smaller waterways. As of October 30, the floods had claimed 373 lives and affected more than two million people, said the government of Thailand.

The Don Muang Airport (also Don Mueang) started to flood on October 25 during a period of high tides. Even as floods were draining into the Gulf of Thailand on Bangkok’s southern shores, high tides pushed back, amplifying the floods. The Chao Phraya reached record levels on October 25, and floods spread across parts of Bangkok. The high tides have peaked, and water levels on the Chao Phraya have dropped slightly. Low tides in the coming days (November 3-15) will give the city time to drain standing floods and prepare for the next high tide, said Thailand’s Flood Relief Operating Center.

The Don Muang Airport, a domestic airport, stopped operations after the runways flooded on October 25. However, the building housed the Flood Relief Operating Center and some 4,000 flood evacuees. The evacuees were forced to leave on October 25, and the Flood Relief Operating Center moved on October 29 when the building flooded. The airplanes shown in the image were decommissioned before the flood. Bangkok’s primary airport, Suvarnabhumi, is still operating and is expected to stay dry.


  1. 24/7 Emergency Operation Center for Flood, Storm and Landslide. (2011, October 24). Flood situation reports. Accessed November 1, 2011.
  2. Bangkok Post. (2011, November 1). All districts in Bangkok still ‘at risk.’ Accessed November 1, 2011.
  3. Bangkok Post. (2011, October 26). Chao Phraya on the brink. Accessed November 1, 2011.
  4. Don Muang Airport Guide. (2011, October 25). Don Muang Airport temporarily closed due to floods. Accessed November 1, 2011.
  5. Government of Thailand. (2011, November 1). Announcement on flooding situation in Bangkok. Published on ReliefWeb. Accessed November 1, 2011.
  6. Government of Thailand. (2011, November 1). FROC: Overall flood situation has improved. Published on ReliefWeb. Accessed November 1, 2011.
  7. Government of Thailand. (2011, October 30). Floods kill 373, affect 2 mil. Published on ReliefWeb. Accessed November 1, 2011.
  8. The Nation. (2011, November 2). Suvarnabhumi ‘will be safe.’ Accessed November 1, 2011, 5:30 EDT).
  9. Poomhirun, C., Prasertpolkrung, J., Hoonsara, S. (2011, October 30). FROC forced to move from Don Mueang. The Nation. Accessed November 1, 2011.
  10. The Nation. (n.d.) What can be expected. Accessed November 1, 2011.

NASA Earth Observatory image created by Jesse Allen and Robert Simmon, using EO-1 ALI data provided courtesy of the NASA EO-1 team. Caption by Holli Riebeek.

Instrument: EO-1 – ALI