Friday, 18 November 2011

Flooding in Southeast Asia : Natural Hazards

Flooding in Southeast Asia
acquired November 1, 2011 download large image (7 MB, JPEG)
Flooding in Southeast Asia
acquired November 12, 2008 download large image (7 MB, JPEG)

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 on November 12, 2008.

The 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 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 drowned in Thailand, and 250 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 that 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, the Bangkok Post reported that all 50 districts of the capital 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 back up the river for three days, just when high water from floods threatened to overwhelm city canals.

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

  1. References

  2. Bangkok Post. (2011, November 1). All districts in Bangkok still “at risk.” Accessed November 1, 2011.
  3. Corben, R. (2011, November 1). As floods drag on in Thailand, displaced grow restless. Voice of America News. Accessed November 1, 2011.
  4. Hunt, L. (2011, November 2 [local time]). Asia counts flood costs. The Diplomat. Accessed November 1, 2011.
  5. 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