Southeast Asia & the Pacific: Water deficits persist in Cambodia, surpluses in Laos & Vietnam

Southeast Asia & the Pacific: Water deficits persist in Cambodia, surpluses in Laos & Vietnam

19 December 2016

The Big Picture
As seen in the 12-month map (below), exceptional water deficits are forecast for Cambodia. Exceptional surpluses are forecast for Laos, Vietnam, North Kalimantan (Indonesian Borneo), and Java. 

Impacts
Heavy rainfall in December produced flooding that has left at least 24 dead in central Vietnam. Damage is estimated at $32 million with over 32,000 hectares of farmland inundated.

At least five people were reported dead due to flooding and landslides in North Sulawesi, Indonesia, and flood waters destroyed the bridge connecting North Sulawesi and Gorontalo province.

In West Nusa Tenggara, Indonesia flooding forced the evacuation of over 100,000 people, damaged thousands of homes, closed schools and businesses, and disrupted power supplies as water levels in some streets reached three meters (nearly 10 feet). In the aftermath disaster officials reported 900 people suffering from respiratory illnesses, skin rashes and diarrhea.

Forecast Breakdown
The 3-month maps (below) show the evolving conditions in more detail. With a few exceptions, the map progression shows a transition to near-normal conditions in much of the region by May.

For the next three months – shown in the December through February map – exceptional deficits will persist in Cambodia west of Tonlé Sap Lake. Moderate to severe deficits are forecast for isolated pockets in central Thailand, and along the Gulf of Papua on New Guinea. Exceptional surpluses are forecast for Laos, central Vietnam, and eastern Gorontalo (Sulawesi, Indonesia). Severe to extreme surpluses are expected in southern Vietnam, the southern Malay Peninsula, and Java.

From March through May the extent of exceptional deficits will shrink in Cambodia. Exceptional surpluses will persist in central Vietnam but surpluses in Laos and eastern Gorontalo will diminish in both extent and severity, and surpluses on Java will nearly disappear. Moderate deficits may emerge in Malaysian Borneo in Kapit Division.

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

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