East Asia: Water surpluses in South China to diminish; deficits ahead for Hokkaido

26 September 2017

The Big Picture
The 12-month forecast map for East Asia (below) indicates extreme to exceptional water deficit conditions in Mongolia and across the border into northern China, and deficits slightly less intense on the Korean Peninsula and into Liaoning. Primarily moderate deficits are forecast scattered along China’s coast and Taiwan, and may be more severe in Zhejiang. Deficits of varying severity are expected in Japan.

Surpluses are forecast in northeastern Jilin; far eastern Inner Mongolia; north-central China in eastern Qinghai surrounding Qinghai Lake; southern China from Poyang Lake in Jiangxi southwest through Hunan into Guangxi and Yunnan; in the western Pearl River Basin (Zhujiang); and in Tibet.

Impacts
Typhoons Hato and Pakhar struck the southeast coast of China in late August, sinking a cargo vessel east of Hong Kong, causing flooding and blackouts in Guangdong Province, and killing 18 people in Macau. Over half of Macau's 600,000 residents lost power in Hato and hundreds of flights were canceled in Hong Kong. Economic losses are estimated at $1 billion.

In mid-September Typhoons Talim and Daksuri forced the evacuation of 200,000 people in China and tens of thousands on Japan's Kyoshu Island.

China's Inner Mongolia Meteorological Bureau reports that, as of September 14, the region has 743,000 square kilometers in drought and that fall crop and forage yields are poor, and fire conditions are high.

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

Recent exceptional deficits in Mongolia are expected to moderate in the near term – September through November – as will deficits on the Korean Peninsula and in Liaoning. Severe to extreme deficits will continue to emerge in Inner Mongolia, and will emerge in Hokkaido, Japan. Conditions in Honshu, Japan will transition to near-normal.

Widespread surpluses are expected to persist in southern China in the western Pearl River Delta, the Leizhou Peninsula, and from Poyang Lake in Jiangxi southwest through Hunan into Guangxi and Yunnan, though the extent of exceptional surpluses will diminish considerably, leaving moderate to extreme surpluses in the region. Surpluses in the coastal southeast will begin to transition to deficits in Zhejiang and Fujian.

Moderate to severe deficits are expected to persist in Sichuan. Extreme surpluses are forecast along the Tongtian River in northwestern Sichuan. Surpluses of varying severity are forecast along the Yarlung (Brahmaputra) River in Tibet, and 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 November, severe to exceptional deficits in northwestern China will increase in extent, reaching from westernmost Xinjiang through Inner Mongolia and into Mongolia, and will include pockets with both deficit and surplus conditions. Moderate deficits will continue to emerge in Southeast China and Taiwan. Aforementioned surpluses in the south are expected to diminish in extent and intensity leaving moderate to severe surpluses in northwestern Jiangxi, western Guangxi, and southern Yunnan.

The forecast for the final months, March through May, indicates an increase in extent and severity of deficits in the southeast and in Mongolia.

(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.