Southeast Asia & the Pacific: Water deficits in Cambodia and Mekong Delta

24 July 2017

The Big Picture
The 12-month composite (below) indicates a large pocket of exceptional water deficits in central Cambodia and a small pocket near Medan in northern Sumatra. Deficits reaching extreme severity are forecast for central Papua New Guinea.

Exceptional surpluses are indicated for western Myanmar and the extreme southeastern region of Sulawesi. More moderate surpluses are forecast for Flores Island, Indonesia; southeast Laos; eastern Cambodia into Vietnam; the northern stretch of the Salween River in eastern Myanmar; and Riau, Sumatra.

Impacts
Cambodia's Ministry of Water Resources and Meteorology is advising citizens - particularly rice farmers - to save water, warning of impending drought in Phnom Penh and neighboring provinces of Kampong Speu, Takeo, Kampot, and Kandal.

Nearly 2 million people were affected by water shortages in 2016 and repercussions continue as Cambodian farmers devastated by last year's drought seek day labor in Thailand. Border checkpoints in northern Cambodia's Banteay Meanchey and Battambang provinces were closed on July 7 in response to a new law passed in Thailand introducing stiff fines and prison sentences for undocumented workers, their employers, and brokers. Thai landowners depend on Cambodia laborers, many of whom are farmers working to pay off equipment loans that became especially burdensome after prolonged drought sharply reduced farm income.

Flooding has continued in Cotabato City, Philippines as rainfall has swollen rivers in the area. By July 21 the number of flood-stricken residents rose to 91,537 from 12,000 in just two days, according to city officials. Crop damage is estimated at P5 million (US$98.5 thousand).

Heavy rainfall in June produced flooding that disrupted Indonesian coal mining operations, reducing exports to China by over 33 percent compared to May and nearly 36 percent below April.

Forecast Breakdown
The 3-month maps (below) show the evolving conditions in more detail.

The July through September forecast map shows the near absence of widespread exceptional surpluses observed in prior months. However, exceptional surpluses are in the forecast for western Myanmar; northern Prachuap Khiri Khan Province, Thailand; the extreme southeastern region of Sulawesi; and Flores Island in Indonesia. Surpluses of lesser severity are forecast for Vietnam east of Cambodia, parts of the Philippines, central Sumatra, western Java, the island of Timor, and southeastern Papua, Indonesia. Severe to exceptional deficits are indicated in much of Cambodia, in Vietnam’s Mekong Delta, and in central Papua New Guinea. Scattered moderate to extreme deficits will emerge in some parts of Thailand, Malaysia, and Borneo.

Conditions evolve in the October-December timeframe with moderate deficits indicated in many parts of the region. Severe to exceptional deficits in Cambodia and in the Mekong Delta will downgrade to moderate during this period, and primarily moderate deficits will emerge across Thailand, on the Malaysian Peninsula, and scattered throughout Indonesia. Papua New Guinea will transition to near-normal conditions in the north with moderate deficits in the south.

Deficits may intensify in Southeast Asia in the Jan-Mar 2018 period.

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

Note on Administrative Boundaries
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