Southeast Asia & the Pacific: WATER Deficits persist in Cambodia, surpluses in Laos & Java

November 23, 2016

The Big Picture
As seen in the 12-month map (below), exceptional water deficits are forecast for Cambodia. Moderate deficits are expected in central Thailand, the Malay Peninsula, Malaysian Borneo, and Brunei. Water surpluses are forecast for Laos, North Kalimantan, Java, and Flores Island. Both surpluses and deficits are forecast for Vietnam.

Impacts
Flooding in West Java Province, Indonesia has displaced over 6,000 people and submerged over 5,000 houses, 12 mosques, 4 school buildings and more than 100 hectares (247 acres) of paddy field. A residential complex in nearby Tangerang was inundated by 2-meter (6.5 feet) high waters. In Gerontalo, Sulawesi heavy rains produced flooding and landslides that forced the evacuation of 4,500 people, left 1,500 homes damaged as well as roads and bridges. Flooding was also reported in several sub-districts of Aceh Jaya, Sumatra where 7,300 people were affected by floodwaters that reached 80-150 cm (2.6-5 feet).

Forecast Breakdown
The 3-month maps (below) show the evolving conditions in more detail. With the obvious exception of Cambodia, the dominant colors are blues and greens from August to January while more areas of yellow and orange appear February through July. In general this indicates a transition away from surplus water conditions to deficit.

Cambodia jumps out in dark red on the November through January map indicating a forecast of exceptional deficit. Both deficits and surpluses are forecast for northernmost Laos, transitioning to exceptional surpluses where the Mekong River takes a sharp turn south near Luang Prabang down to Vientiane. Moderate to exceptional surpluses are forecast for much of the rest of Laos and also in Vietnam’s southern half. Moderate surpluses are forecast for Mindanao, Philippines, and exceptional surpluses are forecast for westernmost Luzon. Moderate surpluses are forecast for eastern Indonesian Borneo, becoming extreme in the northeast. Extreme to exceptional surpluses are forecast for eastern Gorontalo and North Sulawesi. Surpluses of varying severity are forecast for Java, which may be exceptional in some areas. Exceptional surpluses are also forecast for Flores Island.

With the exception of the Philippines, the forecast map for February through April shows a transition away from surplus to emerging deficit. In Southeast Asia exceptional deficits will persist in much of Cambodia. Surpluses in eastern Cambodia, Laos, and Vietnam are forecast to transition to both deficits and surplus. Moderate to occasionally extreme deficits are forecast to emerge in the Malay Peninsula, Sumatra, Malaysian Borneo, western Indonesian Borneo, and southern Sulawesi.

The forecast for the latter three months – May through July – indicates that moderate to severe deficits will continue to emerge in Malaysia and Indonesia.

(It should be noted that forecast skill declines with longer lead times.)