Southeast Asia & the Pacific: Water deficits in Thailand will downgrade

26 July 2019

The 12-month forecast through March 2020 indicates water deficits throughout most of Thailand and into northwestern Cambodia. Deficits will be severe to exceptional in northern Thailand.

Severe deficits are forecast for the tip of the Malay Peninsula and a small pocket in northeastern Sumatra. Primarily moderate deficits are expected in southern Sumatra, much of Java, Indonesian Borneo, and Samar Island in central Philippines. Deficits are forecast for Papua New Guinea in a shore-to-shore column down the center of the nation and will be exceptional around the Gulf of Papua in the south.

Pockets of surplus are forecast in central and southern Myanmar and will be intense in the south. Other areas of surplus include north-central Laos; eastern and southern Cambodia; the Mekong Delta; Cebu, Philippines; Flores Island, Indonesia; and the north-central coast of New Guinea around Jayapura.

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

The forecast through September indicates that deficits in Thailand will downgrade becoming primarily moderate with a few severe pockets, and deficits in Cambodia will nearly disappear. Surpluses will shrink and downgrade in Southeast Asia leaving moderate anomalies in southern Cambodia, from eastern Cambodia into Vietnam, and in the Mekong Delta. A small, intense pocket of surplus will persist in southern Myanmar. Moderate surpluses are forecast for central Philippines. Moderate to severe deficits will emerge in Indonesian Borneo, Singapore, southern Sumatra, and much of Java. Surpluses will persist on Flores Island but will nearly disappear in Papua, Indonesia, persisting along the north shore near Jayapura. Deficits will shrink and downgrade in Papua New Guinea.

From October through December, conditions will normalize throughout much of the region with moderate deficits in Indonesian Borneo, pockets of Sulawesi, and southern New Guinea. A few pockets of surplus are forecast in Myanmar and northern Sumatra.

The forecast for the final months – January through March 2020 – indicates nearly normal conditions in much of the region with some deficits in southern Papua New Guinea and some areas of transition in southern Myanmar as deficits emerge in areas of prior surplus.

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

The Mekong River is at its lowest level in 10 years due to a long dry period during this year’s rainy season. As China’s damming operations exacerbate flow conditions downstream, scientists and people living in Thailand worry that drought combined with China’s dams will lead to irreversible changes to the Mekong River levels, threatening Southeast Asia’s rice-growing regions. 

Northern Thailand is experiencing its worst drought in 40 years, threatening to cut off tap water supply and decimate the region’s rice crops in the face of no substantial rain. 

Tributaries of Cambodia’s Tonle Sap Lake have dried up amid an extended drought, dooming farmers and fishermen in the country’s eastern province of Battambang. This year’s El Niño phenomenon is blamed for high temperatures that have resulted in drying rice fields and smaller fishable areas. Villagers in the province’s Aek Phnom district say they have been unable to fish since April, and are pleading with the government for aid. The provincial governor claimed that federal authorities are working to provide emergency food supplies, while the Cambodian Human Rights and Development Association said that longer-term solutions, like providing people farmable land, are needed to improve living standards. 

Heavy rains in Myanmar swelled the Belin River prompting four flood relief camps to open to assist families living on the riverbank in the Belin Township.

There are numerous regions around the world where country borders are contested. ISciences depicts country boundaries on these maps solely to provide some geographic context. The boundaries are nominal, not legal, descriptions of each entity. The use of these boundaries does not imply any judgement on the legal status of any territory, or any endorsement or acceptance of disputed boundaries on the part of ISciences or our data providers.

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Many analyses reported in ISciences-authored blog posts are based on data generated by the ISciences Water Security Indicator Model (WSIM). Other sources, if used, are referenced in footnotes accompanying individual posts. WSIM is a validated capability that produces monthly reports on current and forecast global freshwater surpluses and deficits with lead times of 1-9 months at 0.5°x0.5° resolution. This capability has been in continuous operation since April 2011 and has proven to provide reliable forecasts of emerging water security concerns in that time-frame. WSIM has the ability to assess the impacts of water anomalies on people, agriculture, and electricity generation. Detailed data, customized visualizations, and reports are available for purchase.

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