East Asia: Water deficits forecast to continue in North & Northeast, surpluses in South

23 August 2017

The Big Picture
The 12-month forecast map for East Asia (below) indicates extreme to exceptional water deficit conditions in Mongolia, across northern China, and on the Korean Peninsula. Deficits are also forecast in central China from southern Gansu to the East China Sea and in southern Honshu, Japan.

Surpluses are forecast in: Northeast China from northeastern Jilin into Heilongjiang; north-central China in eastern Qinghai surrounding Qinghai Lake; southern China from Poyang Lake in Jiangxi southwest through Hunan into Guizhou and Yunnan, and northern Yunnan into central Sichuan; along the Pearl River (Zhujiang) and parts of the coastal southeast; and in Tibet.

Impacts
About a third of Mongolia was in severe drought at the end of July, prompting the country's Ministry of Agriculture and Industry to ban grain exports amid fears of crop shortfalls. The drought has been accompanied by a heatwave that produced the highest temperatures recorded in 56 years. Temperatures in Mongolia have risen 2°C (3.6°F) in the last 70 years, three times faster than the global average according to UNEP (United Nations Environment Programme).

Drought conditions persist across central and northern China, reports China’s National Meteorological Center, affecting up to 2.67 million cultivated hectares, especially in western Liaoning and Jilin provinces where the weather is negatively impacting grain production yield potential. Liaoning and Jilin accounted for 20 percent of China's corn production in 2016.

The UN Food and Agricultural Organization is calling attention to what it describes as the worst drought in 16 years in North Korea. Inadequate rainfall in the spring planting season reduced production by 30 percent over the previous year, and FAO is appealing for food aid over the next three months to avert severe shortages.

Elsewhere in East Asia, July flooding resulted in damages totaling $10 billion in China, much of which was in the Yangtze River Basin, and nearly $1 billion in Japan, reports reinsurance broker Aon Benfield, noting that these losses are primarily uninsured.

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

Recent exceptional deficits in Mongolia into Northeast China, on the Korean Peninsula, and in Honshu, Japan are expected to moderate in the near term – August through October – but severe to extreme deficits will continue to emerge in the northeast and in the border region between Liaoning Province and North Korea. Primarily moderate deficits will emerge in central China from southern Gansu to the East China Sea and may be more intense in southern Gansu and across the border into northern Sichuan. Widespread moderate to severe water surpluses are forecast during this period across much of southern China including the Pearl River (Zhujiang). Surpluses of varying severity are forecast for Tibet including along the Nu (Salween) River and Yarlung (Brahmaputra) River. Exceptional surpluses are forecast in western Tibet and surrounding Qinghai Lake in north-central China. Both deficits and surpluses are forecast in the Tarim Basin of northwest China’s Xinjiang Province.

After October severe to exceptional deficits in northwestern China will increase in extent, reaching from westernmost Xinjiang through Inner Mongolia and Mongolia, and will include some pockets with both deficit and surplus conditions. Moderate to extreme deficits will continue to emerge in Northeast China into northern North Korea; primarily moderate deficits will continue in the North China Plain (eastern China). Surpluses will continue to emerge in western Tibet and surrounding Qinghai Lake in the north, but conditions in southeastern China will return to near-normal.

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

Note on Administrative Boundaries
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.