Managing Water for Sustainable
Utilization as China Warms
Guoqing Wang1,2* and Yueyang Wang3
1State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, China
2Research Center for Climate Change, China
3School of Geographical Sciences, Nanjing University of Information Science and Technology, China
Submission: January 25, 2019; Published: February 06, 2019
*Corresponding author: Guoqing Wang, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute and Research Center for Climate Change, Ministry of Water Resources, Nanjing, 210029, China
How to cite this article: Guoqing W, Yueyang W. Managing Water for Sustainable Utilization as China Warms. Int J Environ Sci Nat Res. 2019; 17(1):
Population growth, urbanisation and industrialisation are increasing demands and polluting sources of water. Climate change is one of several pressures on water resources in China. Although climate models agree warming will continue, rainfall projections are less certain. However, the prevailing pattern of ‘north dry, south wet’ looks set to persist, exacerbating water scarcity in some northern regions important for agriculture. As China’s economy grows and competition for water intensifies, China will need to develop robust systems for managing water in an uncertain but increasingly volatile climate, particularly in the water-scarce north. This may require a new style of adaptive management, combining use of non-traditional sources such as urban waste water with better management of existing storage, and much more emphasis on water conservation and reallocation.
Keywords: Climate change; Water resources management; Adaptation
In the next few decades, climate change in China will add pressure on water resources already under intense stress. China’s successful investments in water-related infrastructure have helped mitigate climate variability and strengthen water, food and energy security; but the country’s water supplies are now dwindling under a combination of population growth, rising per capita demand, urbanisation, industrialisation and pollution, particularly in the water-scarce north.
According to estimates of surface and groundwater flows, China has the world’s sixth largest renewable water resources, roughly 2841km3/year, but the water available per capita is only about 2151m3/year, less than 30% of the global average . Moreover, these scant water resources are unevenly distributed across the country and fluctuate dramatically over time. South and east China receive strong rains during the summer monsoon, raising their annual average rainfall to around 2,000mm/year. Rainfall in the much drier west and north is less than one-fifth of this, only 200-400mm/year . Regions with less than 1000m3 rainfall per capita per year are commonly defined as ‘water scarce’ ; northern China has only 750m3 per capita per year, less than one-fourth the rain per capita in the south and one-eleventh of the world average. With very limited water, the north nonetheless supports over 40% of the national population, has 60% of the arable land and generates over 40% of China’s GDP.
The region produces roughly half of China’s grain and nearly all its wheat and maize . Rainfall in China also varies greatly from season to season and year to year, with a strong monsoonal influence. Droughts and floods are frequent, often occurring simultaneously in different regions. The Yangtze basin, for example, sees severe floods roughly once every 10 years, most recently in 1998, when flood water inundated 21 million ha of land and destroyed five million houses, causing an economic loss of over US$20 billion . Droughts, however, are responsible for the biggest economic losses and can devastate livelihoods in rural areas. A serious drought across five southwestern provinces in 2009-2010 affected roughly 7.7 million ha of farmland and left 24 million people and 15 million livestock struggling to access water. Direct economic losses, by late 2010, were estimated at US$3.6 billion . Climate change is likely to exacerbate these extreme events, increase the disparity between dry and wet regions, or alter seasonal patterns, and exacerbate these strains. It is therefore the water sector being one of four priority areas for adaptation identified in China’s national climate change adaptation programme.
Across China as a whole, water resources have shrunk since the 1980s though some regions have dried less or become wetter. The World Bank estimates the cost of water scarcity and
pollution at around 2.3% of GDP . Agriculture remains China’s
biggest water user, accounting for roughly 63% of withdrawals,
mainly in the north . This share is slowly declining as water
conservation policies generate more ‘crop per drop’ and
release water for fast-growing urban and industrial sectors. As
combined demands rise, so does the production of wastewater
and pollution, making clean water even scarcer.
It is challenging to untangle how much of the decline in
water supply is due to rising demand and pollution, and how
much to climate trends. These drivers were separated by
using climate records, water consumption statistics and highresolution
hydrological models . China’s climate overall has
warmed since 1960 (by 1.2°C); the northeast has warmed most,
the southwest least. Country-wide precipitation over the same
period has not changed significantly, but there are significant
differences between the northeast (decreasing), the northwest
(increasing) and the southeast (increasing) .
In the Yellow River basin in north China, with less rainfall
and higher temperatures, river flows have fallen sharply over
the last 40 years, particularly in the lower reaches of the basin
(Figure 1). This reflects both climate trends and human activity,
but increased withdrawals of water for irrigation, industry and
domestic use are dominant, accounting for roughly 62% of the
reduction in flow from the 1955-1970 baseline . In the Haihe
basin in the northeast, one of China’s most water-stressed,
human activities are also the major cause of declining flows .
Flows recorded at Datong in the lower Yangtze River show
no marked trends in the period 1950-2010 (Figure 1). Flows
have actually declined in the upper basin, due in part to less
precipitation. In the middle and lower basin, however, increased
precipitation and frequent rainstorms have swelled summer
flows. A similar pattern is found in the Pearl River further south.
Before now, assessments of future climate change in China
have been based on the average of several Global Climate
Models. These suggest that with medium levels of greenhouse
gas emissions (a scenario known as A1B and RCP4.5), China’s
air temperature will rise by 0.27-0.32℃/10a during 2021-2050
and precipitation will increase by an average of 1.1-2.3 by 2050
relative to 1961-1990, with more frequent heavy downpours.
However, multi-model averages conceal significant variation,
with different climate models projecting very different climate
Using downscaled climate scenarios to drive hydrological
models, we project how much runoff will be feeding Chinese
rivers by mid-century. Whether future emissions are high,
medium or low, annual runoff in the Yellow River basin of northcentral
China — a key grain-producing area — declines by
roughly 2.3-5.7% from the period 1961-1990 to 2021-2050 with
increasing risk of extreme events including flood and drought
to some extent. For other river basins, the expected changes
depend on the emissions scenario (Figure 2). In some cases,recent declines are projected to reverse: for example, the RCP4.5
scenario of GFDL-ESM2M and NORESM1-M leads to less flow in
the northern, water-stressed Hai and Yellow River basins.
Particularly important for agriculture are changes during
June-September, the flooding and growing season. Trends for
this period are similar but more pronounced. Hence, droughts
affecting areas such as the Yellow River basin are most likely to hit
during summer and harm crops, while other basins experience
more intense summer rainfall and, potentially, flooding.
As China’s economy grows and competition for water
increases, China will need to develop robust systems for
managing water in an uncertain but increasingly volatile climate,
particularly in the water-scarce north. Although changes in
projected runoff remain uncertain for most basins, regional
water shortages and regional flooding remain key issues that
are likely to grow in importance as climate change amplifies
existing patterns of shortage and excess. These pressures
and uncertainties may require a new style of adaptive water
management, combining use of non-traditional sources such
as urban waste water with better management of existing
storage, and much more emphasis on water conservation and
reallocation. China’s future measures to adapt to the coming
a) Understand the importance and irreversible impacts
of climate change on water resources and incorporate the
impacts of climate change into water resources assessment
b) Improve the repeated and circular utilization of water
resources, enhance management of water demand and build
a water-saving society.
c) In the most vulnerable regions, construct new water
infrastructure, adopt strict water-conservation policies and
maintain the capacity of water resources.
d) Diversify available water resources by increasing the
use of unconventional sources.
e) Develop better emergency response plans and improve
institutions and capacity for emergency responses to
f) Accelerate the development of the national water
resources management and information system, to provide
reliable information for management and decision-making.
g) Increase awareness of climate risks and adopt a new
mindset on water resource management.
Declining flows in the Yellow and Haihe river basins are
mostly due to human consumption, whereas climate change is
already a major factor affecting the Yangtze and Pearl rivers.
Different scenarios associated with different runoff changes.
Under all emissions scenarios, annual runoff in the grain-rich
Yellow River basin is expected to decline 2.3-5.7%.
Climate change in China adds pressure on water resources
already under stress, making the water sector a top priority
in China’s national adaptation programme. The most detailed
climate impact projections to date call for aggressive measures
to ensure China doesn’t run dry.
This study has been financially supported by the National
Key Research and Development Programs of China (Grants:
2016YFA0601501, 2016YFA0601601), the National Natural
Science Foundation of China (Grants: 41830863, 51879162,
41601025), and State Key Laboratory of Hydrology-Water
Resources and Hydraulic Engineering (Grant No. 2017490211).Many thanks also go to Prof. Ying Xu from China Meteorological
Administration for providing climate scenarios.