City clusters in China: air and surface water pollution
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REVIEWS REVIEWS REVIEWS
353
City clusters in China: air and surface water
pollution
Min Shao, Xiaoyan Tang*, Yuanhang Zhang, and Wenjun Li
City clusters are made up of groups of large, nearly contiguous cities with many adjoining satellite cities and
towns. Over the past two decades, such clusters have played a leading role in the economic growth of China,
owing to their collective economic capacity and interdependency. However, the economic boom has led to a
general decline in environmental quality. This paper will review the development and current status of the
major environmental problems caused by city clusters, focusing on water and air pollution, and suggest possi-
ble strategies for solving these problems. Currently, deteriorating water quality is of major concern to the pub-
lic and decision makers alike, and more than three-quarters of the urban population are exposed to air quality
that does not meet the national ambient air quality standards of China. Furthermore, this pollution is charac-
terized by high concentrations of both primary and secondary pollutants. Environmental pollution issues are
therefore much more complex in China than in western countries. China is expected to quadruple its GDP by
2020 (using 2000 as the base year for comparison) and, consequently, will face even more serious environmen-
tal challenges. Improving energy efficiency and moderating the consumption of natural resources are essential
if China is to achieve a balance between economic development and environmental health.
Front Ecol Environ 2006; 4(7): 353–361
C hina has experienced unprecedented economic
growth over the past two decades, accompanied by
the development of large-scale industries and services. In
small towns have sprung up around the larger cities, form-
ing city clusters, often with similar or interdependent
economies.
the course of this expansion, medium-sized cities and The development of city clusters in China is somewhat
similar to the formation of the megalopolis in the United
In a nutshell: States, as described by Gottmann (1961). However, there
• The emergence of city clusters, large groups of cities and towns are some differences in terms of the number of cities in an
in close proximity to one another, has contributed to China’s area, their infrastructure, and the services they provide to
rapid economic growth over the past 20 years the region, as compared to the US. City clusters in China
• However, environmental quality has deteriorated within and
around these clusters, with pollution issues becoming widespread
tend to be much more concentrated and densely popu-
• Air pollution, especially increasing levels of fine particles and lated, with little room for natural areas; for example, the
ground-level ozone, is a growing environmental problem in city clus- distance between cities is often less than 10 km in the
ters, and a multi-objective strategy is necessary for effective control Pearl River delta. In the city of Guangzhou, spacing
• China must improve its energy efficiency and resource con- between residential buildings is so restricted that they are
sumption in order to achieve environmentally friendly eco-
nomic development and a sustainable society
often referred to as “handshaking” buildings. Also, there
is no clear, functional division of infrastructures among
the cities, due to a lack of coordination between city
Authors’ contact details are on p361 planners. Cities within a cluster often compete for avail-
© The Ecological Society of America www.frontiersinecology.org
Environmental pollution and city clusters M Shao et al.
354 ization has resulted in substantial environ-
mental problems throughout China, but
nowhere more so than in city clusters. A
considerable part of China’s GDP was
achieved at the cost of over-consumption
of energy and other natural resources. The
Pearl River delta, for example, although
Northeast Plain accounting for only about 20% of
Guangdong province, consumed 67% of
Mid China Plain the coal and 85% of the oil for the entire
region. Due to the close proximity of the
Beijing–Tianjin–Bohai
cities and the large number of emissions
Guanzhong
sources, ambient concentrations of SO2
and NO2 in the Pearl River delta region
Wuhan Yangtze River delta were 2–3 times the level found in other
parts of the province (CESPKU and GIES
2004). Pollutants from various cities in
Changsha Legend
the area tend to mix and spread over the
entire region (Wang SL et al. 2005).
City City cluster
There is an urgent need to incorporate
P > 10 M Large environmental issues into planning
5M–10M
1M–5M
China’s urban areas, in order to reduce the
Medium
Pearl River delta
0.5M–1M risks of further environmental degrada-
< 0.5M Small
tion. This paper briefly describes the role
of city clusters in China’s economic devel-
Figure 1. The distribution of city clusters in eastern China. The closed dots opment, and describes the regional air and
indicate cities, sized according to urban population size; the dashed circles indicate watershed pollution that has developed as
city clusters, sized according to GDP. Details of the Northeast plains, Beijing– a result of the rapid economic growth
Tianjin–Bohai Bay area, Yangtze River delta, and Pearl River delta are given in within these city clusters. We also propose
Table 1; the other city clusters are generally development zones around one large possible solutions to these environmental
city. Central-China plains, Guanzhong, Wuhan, and Changsha are used as problems, taking into account the social
names of city clusters near the cities of Zhengzhou, Xi’an, Wuhan, and Changsha and economic plans for medium- and
cities, respectively. Redrawn from Zhang (2004). long-term development in China.
able natural resources, investment, and regional funding Economic growth in city clusters
for infrastructure development and improvement. For
example, five separate international airports have been Urbanization in China has occurred most rapidly in the
constructed in recent years in the Pearl River delta coastal areas, due to the stronger economic base and more
(including Hong Kong and Macau). Better intercity developed infrastructure, as well as the greater abundance
cooperation could avoid such wasteful redundancy in the of natural resources. As a result, several city clusters have
future, resulting in a more efficient regional economy arisen in coastal areas and nearby regions (Figure 1). For
(Bao 2005). several reasons, the formation of city clusters often acts as
If, as expected, such rapid development continues over a catalyst for economic growth and enhances the compet-
the next several decades, demographic trends suggest that itiveness of the region as a whole. The central govern-
China will experience an even greater rate of urbaniza- ment has therefore developed long-term plans to support
tion. Population in urban areas has already increased rapid coastal urbanization, followed by efforts to increase
from 20.0% of the total population in 1980 to 36.1% in urbanization, in the central part of the country, thereby
2000 (National Bureau of Statistics 2001a), and reached aiding economic development (National Bureau of
37.8 % in 2003 (Li and Ji 2003). Despite this rapid pace Statistics 2001b). In essence, the three largest city clus-
of urbanization, current levels are still far below the ters – the Beijing–Tianjin–Bohai Bay, Yangtze River
global average (48.3% in 2003; United Nations delta, and Pearl River delta regions – have become the
Population Division 2004). There is still great potential forerunners of modernization in China.
for further urbanization, therefore, particularly as the At present, the Yangtze River delta and Pearl River delta
urbanization process catches up with the pace of industri- areas are the most fully developed, followed by the
alization, which is often just as fast in villages (National Beijing–Tianjin–Bohai Bay cluster and the recently initi-
Bureau of Statistics 1999). ated Northeast cluster (Table 1). The Pearl River delta city
The combination of rapid economic growth and urban- cluster has expanded rapidly since the 1980s, due primarily
www.frontiersinecology.org © The Ecological Society of America
M Shao et al. Environmental pollution and city clusters
to former political leader Table 1. The contribution to national GDP from the four major city clusters in 2002 355
Deng Xiaoping’s policy of GDP per capita Percentage
creating “special economic Number Area Population (1000 yuan in national
zones”, designated regions City clusters of cities Megacities (1000 km2) (million) person–1) GDP (%)
where governmental policy
Pearl River 25 Guangzhou,
fosters a market economy delta Shenzhen 41.7 23.0 35.7 11.4
instead of a planned econ-
omy. Similarly, the exponen- Yangtze River 43 Shanghai, 99.6 75.3 22.5 23.7
tial economic growth of delta Nanjing,
Shanghai in the 1990s led Hangzhou
rapidly to accelerated growth Beijing–Tianjin– Beijing,Tianjin,
among cities in its neighbor- Bohai Bay 9 Tangshan 55.3 35.1 14.2 7.0
hood. The Beijing–Tianjin–
Bohai Bay area is a unique Northeast plain 17 Shenyang,
city cluster that formed spon- Dalian 77.1 27.0 13.5 5.1
taneously around the twin National Bureau of Statistics (2002)
megacities of Beijing and
Tianjin. and academics (World Bank 1997). Although later esti-
The Northeast plains cluster, the former national cen- mates provided different numbers, by the end of the 20th
ter for heavy industry from the 1950s and throughout the century, economic losses due to environmental pollution
1980s, is now facing major challenges in maintaining its were probably around 4–5% of GDP, which is comparable
economic strength, following the exhaustion of its once to the 5% estimated for the US in the mid-1970s and the
abundant natural resources, especially coal, oil, and iron 3–5% estimated for the European Union in the mid-
ore. Industrial restructuring and rehabilitation are mak- 1980s (Xu 1998). However, there are no truly reliable
ing the Northeast cluster China’s fourth economic pillar estimates of the impact that pollution from city clusters
(Table 1). While these four regions make up less than 3 % has on GDP, despite the importance of the issue.
of China’s territory, and encompass only about 12% of the
country’s total population, they account for nearly half of Watershed pollution
the national GDP (47% in 2001; National Bureau of
Statistics 2002). China has insufficient water resources. The amount of
Although the government has also supported increased fresh water available per capita is about one-quarter of
urbanization of small towns (Bai 2002), it is the large city the global average of 8513 m3 per year (2002 statistics;
clusters that are expected to drive economic develop- World Bank 2003). In a survey of more than 600 Chinese
ment for the foreseeable future (Li and Ji 2003). Even so, cities, two-thirds had inadequate water supplies, while
it is widely predicted that millions of people will migrate 1 in 6 experienced severe water shortages (Li 2003).
from rural areas to adjacent urban areas over the next sev- Water pollution caused by rapid urbanization and the for-
eral decades, leading to the widespread growth of small mation of city clusters has exacerbated the lack of acces-
and medium-sized cities, some of which are likely to sible drinking water. While levels of industrial wastewater
become part of future city clusters. For instance, Henan discharge have largely stabilized, domestic wastewater has
Province, formerly a relatively poor agricultural province increased considerably. While the total amount of
but with the largest population of any of China’s released industrial wastewater fluctuated around 22 bil-
provinces, has since grown to become the fifth largest lion tons from 1995 to 2004, the domestic sewage dis-
provincial economy in China, based on GDP (2004 sta- charge increased from 13.1 billion tons in 1995 to
tistics; Zhang 2005). This economic expansion was due 22.1 billion tons in 2000, and up to 26.1 billion tons in
primarily to urban migrations and a subsequent shift in 2004 (State Environmental Protection Administration
the economic base, from agricultural to industrial. [SEPA] 1995–2004). This was due primarily to the enact-
Meanwhile, the Central-China plains city cluster in the ment of more stringent controls on industrial sources of
same province is also growing very quickly. These devel- wastewater; in 2003, 91% of industrial wastewater was
opments are seen as a rejuvenation of economic strength treated, in contrast to only 32% of urban domestic sewage
in central China. (National Bureau of Statistics 2004).
The city clusters have major advantages in terms of As a consequence, surface water quality has become an
regional economic development: the drop in GDP due to issue of great concern in China. A national survey of
environmental pollution resulting from such rapid eco- seven major rivers in China, carried out in 2004, revealed
nomic growth has largely been ignored. In 1997, a World that water quality measurements in 28% of 412 moni-
Bank report indicated that economic losses caused by tored sections were below grade V, the worst grade in the
environmental pollution in China ranged from 3–8 % of national standard for water quality in China. These
GDP, which attracted the attention of both policy makers results indicate that, for these sections of river at least,
© The Ecological Society of America www.frontiersinecology.org
Environmental pollution and city clusters M Shao et al.
356 of the monitored sections of these two
rivers also revealed water quality worse
than grade V, and all monitored sections
Songhuajiang in the urban area of Guangzhou (on the
Pearl River) had water quality around
grade V or worse. The water quality of
Liaohe
the rivers shown in Figure 2 was charac-
terized only by conventional indicators,
Haihe such as chemical oxygen demand
(COD), ammonia, and volatile phenols,
Yellow River
among others. The situation is even
Huaihe
more worrisome when endocrine disrupt-
ing organic substances are taken into
Legend Yangtze River consideration as well (An and Hu 2006).
Grade I – III Lake Taihu, the third largest freshwa-
Grade IV– V ter lake in China, provides a typical
Pearl River
Grade > V example of water pollution caused by
River city clusters. With a total watershed
Watershed area of about 36 500 km2, Taihu is situ-
ated within Jiangsu and Zhejiang
Figure 2. Water quality of seven major rivers in China. The length of the bars are provinces. The city of Shanghai, as well
normalized to 1; the lengths of the green, yellow, and red bars represent the percentages as more than 37 other cities and towns,
of each river section with water quality between grades I–III, between grades IV–V, is sited within its watershed. GDP in
and grade V or worse, respectively. (According to the national surface water quality the area around Lake Taihu increased
standards of China [GB3838-2002], water of grades I–III is suitable for drinking, by a factor of 17 between 1980 and
grade IV is for industrial and recreational use, and grade V is for agricultural use). 1998; per capita GDP in the area was
three times the national average (State
the water supply is virtually of no practical or functional Council of China 1998), while the population density
use, even for agricultural irrigation. For the Haihe River, was eight times the national average (Gao et al 2003). The
which provides the cities of Beijing and Tianjin with the water quality of Lake Taihu has deteriorated greatly during
bulk of their drinking water, this figure was as high as this period (Figure 3), largely as a result of this rapid eco-
57%, and for the Liaohe River, which supplies water to nomic growth. The lake remains the most important
Northeast China, it was 38% (see Figure 2 for the loca- source of drinking water for the inhabitants of the Yangtze
tions of these rivers). Overall, more than 90% of the river River delta region, but water quality has dropped by
sections that flowed through urban areas showed a water approximately one grade level every decade (Qin et al.
quality of grade V or worse (SEPA 1995–2004). The 2004), and in 2004 nearly 60% of sampling sites in the
higher the grade, the worse the water quality; only water lake recorded water quality lower than grade V (SEPA
with a grade lower than III is drinkable. The same survey 1995–2004). As a result, the entire watershed area is now
suggested that even the water quality of the Yangtze and facing a shortage of potable water. Residents in the area
Pearl Rivers, both of which have relatively abundant who enjoyed the clean water of the lake in the past are
water flow, was a cause for concern; approximately 10% now compelled to buy bottled water for drinking.
According to Gao et al. (2003), over
March 1981 February 1991 February 2001 80% of COD and 70% of total phos-
phorus originated from urban and resi-
dential areas around the lake, with 42%
of COD and 60% of total phosphorus
derived from domestic sewage dis-
charge. Research has shown that
increased phosphorus concentration is
the key factor in the worsening
eutrophication of Lake Taihu (Dokulil
et al. 2000); domestic sewage is there-
Grade III Grade II Grade IV Grade V fore clearly a major source of water pol-
lution in the lake. Future conversion of
Figure 3. Historical trends in water quality in Taihu lake. The water quality grading agricultural areas in the watershed to
system is the same as in Figure 2. (Derived from monitoring data provided by urban environments will very probably
National Environmental Monitoring Center.) lead to even greater levels of water pol-
www.frontiersinecology.org © The Ecological Society of America
M Shao et al. Environmental pollution and city clusters lution (Gao et al. 2003). The 357 deteriorating condition of Lake Taihu is typical of the problems associated with the increasingly polluted nature of China’s sources of freshwater, and illus- trates the urgent need to inte- grate both water pollution and population controls into the planning for future economic development in the country’s watersheds. Regional air pollution Air pollution is perhaps China’s biggest environmental problem. Results from routine monitoring of 360 cities in 2004 revealed that the air quality of nearly 70% of urban areas did not meet the Figure 4. Distribution of aerosol optical depth over China in 2002 (Li et al. 2003). country’s national ambient air quality standards (NAAQS), and that nearly 75% of levels increased by 9.5% from 1970 to 1979 and by 21.8% urban residents were regularly exposed to air considered from 1980 to 1989 (Luo et al. 2002). unsuitable for inhabited areas (SEPA 1995–2004). In recent years, the “gray sky” phenomenon has been China has high levels of sulfur dioxide (SO2) and total the subject of growing public concern (Figure 5). suspended particulates (TSP), because coal is the source Research shows that high levels of ambient fine particles of 60–70% of its primary energy. Meanwhile, the number (PM2.5, ie airborne particulate matter with diameters less of motor vehicles has increased substantially since the than 2.5 m) lead to poor visibility (Song et al. 2003). In mid-1980s, primarily in urban areas and city clusters; in 2001, the concentration of PM2.5 in Beijing averaged Beijing, for example, the number of vehicles increased 110 g m–3, more than seven times the ambient air qual- from 0.5 million in 1990 to 2 million in 2002 (Beijing ity standard recommended by the US Environmental Municipal Bureau of Statistics 2003). The growing num- Protection Agency for fine particulate matter (Wang et ber of cars and trucks has led to much higher levels of al. 2004). Fine particle pollution in urban areas poses a atmospheric nitrogen oxides throughout the country, but serious health risk to residents, but particularly to indi- especially in urban areas. viduals who suffer from respiratory ailments, the elderly, Since 2000, high concentrations of aerial particulate and children (Zhang et al. 2002; Li et al. 2005). Such matter with diameters less than 10m (PM10) are the severe fine-particle pollution is seldom observed in devel- most frequent cause of NAAQS grade II violations (that oped countries. is, an average annual concentration of such particulate The very high PM2.5 levels are most probably the result matter at concentrations ≤ 100 g m–3). In Beijing, the of secondary particle production due to chemical reac- annual average level of PM10 fluctuated around 160 g tions in the atmosphere. Ground-level ozone (a typical m–3 from 2000 to 2004 (Beijing EPB 2005 ). Megacities component of photochemical smog) is formed by the reac- such as Beijing, Shanghai, and Guangzhou are frequently tions of NOx and volatile organic compounds (VOCs) among the cities of the world with the highest levels of under solar radiation (Haggen-Smit 1952). Areas of ele- airborne particulate matter (UNEP 2002). vated fine particulate concentrations can also form down- Large areas of China are exposed to high levels of par- wind of the precursor source areas if there is considerable ticulate pollution (Figure 4). For example, the vast region movement of air. More importantly, atmospheric oxida- extending from the North China plain down to the tion capacities are enhanced by increasing O3 concentra- Yangtze River delta and the heavily urbanized Pearl River tions (Wennberg et al. 1998). Thus, SO2, NOx, and delta region show aerosol optical depths (AOD) of volatile organic compounds will be transformed into fine 0.6–0.8 (AOD is an index describing the absorption of particles (ie PM2.5) more efficiently where O3 concentra- light due to atmospheric particles ie the opaqueness of tions are higher due to increased rates of oxidation. the air). In contrast, the AOD for Europe measures High concentrations of ground-level ozone have been between 0.5 and 0.1 for industrialized and rural areas, observed for many years in China’s urban areas. For respectively (Gonzales et al. 2000). A study of 30-year example, researchers at Peking University measuring the variations of atmospheric AOD in China showed that diurnal variations of episodic ground-level ozone in © The Ecological Society of America www.frontiersinecology.org
Environmental pollution and city clusters M Shao et al.
358 (a) (b)
© T Thomas, Inst of Tropospheric Research, Germany and M Hu, Peking University
Figure 5. Photographs of Beijing, taken from the top of a building on the campus of Peking University, (a) on a clear day and
(b) on a hazy day.
Beijing from 1982 to 2003 found that O3 concentrations the conversion of SO2, NOx, and VOCs into sulfates,
have increased sharply since the 1990s, and often exceed nitrates, and particulate organic matter, and how these fine
200 ppb (Figure 6). A similar study in the Yangtze River particles, in turn, play a catalytic role in further heteroge-
delta region showed that high ozone concentrations are neous reactions (Ravishankara 1997). While it is true that
also often found at sites some distance removed from these processes are observed in many locations around the
urbanized or industrial regions (Wang et al. 2005). world, the conditions prevalent in China – high concen-
Such high levels of both primary and secondary airborne trations of SO2, oxidants, and their precursor components,
pollutants lead to the development of a (perhaps typically as well as the comparatively high concentrations of sus-
Chinese) “air pollution complex” concept (Figure 7). The pended particles, etc – result in a level of aerial chemical
main purpose of the air pollution complex model is to interactions that is probably unique to the country.
underscore the variety of interactions of airborne pollu- In recent years, intensive efforts have been made to
tants in China: how increased atmospheric oxidation reduce air pollution in China. Countermeasures, such as
capacity, caused by the formation of ozone, will speed up adapting energy production (including shifting primary
energy production from coal to gas),
reducing sulfur emissions through
300
April–June 1982 (ZGC) June 1987 (city average) increased use of low-sulfur coal and fuel
June 1993 (ZGC) June 1997 (ZGC)
gas desulfurization, and promoting more
June 2000 (ZGC) 10–24 Aug 2003 (Olympic site)
250 stringent vehicular emission standards as
well as switching to non-leaded gasoline,
200 have been implemented in urban areas
O3 (g m-3)
throughout the country. These measures
150 have, to some extent, slowed the rate of
increase of pollutant emissions (Figure
100
8). Nevertheless, while these measures
might be effective for the abatement of
some primary pollutants, they are insuffi-
50
cient for the control of secondary pollu-
tants and the resulting chemical interac-
0 tions that form the core of the air
0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 24:00
Beijing time pollution complex model.
The pollution complex concept might
Figure 6. Trends in the episodic concentrations of ambient O3 measured in Beijing also be applicable to water pollution, in
from 1982 to 2003 in Zhongguancun (ZGC), a northwest suburb of the city, about view of the interactions between aque-
20 km of Tian’anmen square. The 2008 Olympic Games site is about 4 km north of ous pollutants (eg metals, nitrogen, and
ZGC. The yellow line indicates the 1-hour average O3 concentration at grade II, organic material) and the interfaces
according to the national ambient air quality standards of China (2000 amendment among water, sediment, and aquatic
to GB3095-1996). organisms. Furthermore, exchange of
www.frontiersinecology.org © The Ecological Society of America
M Shao et al. Environmental pollution and city clusters
359
PM2.5 PM, O3 at higher
Oxidant concentrations
PM, O3 (O3, OH) (SO42-, NO3-)
Inflow hy Outflow
SO2, NOx PM10, PM2.5
HC, NOx
Biogenic Deposition
Anthropogenic Flux
Figure 7. “Air pollution complex” concept in a Chinese city cluster.
materials between the atmosphere, pedosphere, and the China’s already fragile freshwater ecosystems will come
terrestrial and aquatic ecosystems (eg the nitrogen cycle) under even greater strain.
links air, water, and soil pollution together, suggesting Low energy efficiency is one of the main causes of air
that the control of the pollution complex requires an pollution in China. Currently, the nation is one of the
integrated approach. While abundant expertise from world’s biggest consumers of energy and materials, but is
Europe and the US is available to address pollution prob- very inefficient in the use of these resources (Imhoff et al.
lems (such as photochemical smog, acid deposition, and 2004). While China’s GDP accounted for only one-
suspended particles), the knowledge and experience thirtieth of the total global GDP, raw material consump-
needed to find solutions to the unique pollution complex tion rates were much higher; for instance, China’s steel,
in China are still lacking. coal, and cement consumption accounted for 25%, 33%,
and 20% of world totals, respectively (Guo 2004).
Challenges for future development The increase in vehicular traffic is another main cause
of air pollution. China is anticipating a threefold to sev-
The Chinese Government has set as a goal the doubling of enfold increase in the number of motorized vehicles
the country’s GDP (using 2000 as the baseline) by 2010, between 2002 and 2020. It is projected that CO2 emis-
and quadrupling it by 2020. As a
result, each province and city, from 25 15000
SO2, dust emission and COD discharge (million tons)
the coastal areas to the western parts
of China, has created its own eco- SO2 emissions
nomic development plans accord- 20 12000
GDP (billion yuan RMB)
Number of private cars (million)
ingly. A new round of rapid eco-
nomic development is therefore GDP
expected to spread across the coun- 15 9000
try. More city clusters will be gener- Discharge of COD
ated as a result, and the natural envi-
10 6000
ronment will be subjected to even Smoke and dust emission
greater stress.
If, by 2020, 50% of China’s popu- 5 Numbers of private cars 3000
lation live in towns and cities,
domestic water needs will be double
those of 2000, while industrial use 0 0
will increase 1.5 times (Peng 2002). 1994 1996 1998 2000 2002 2004
As water consumption rises, so too
will the amount of discharged Figure 8. GDP, number of cars, and emission of SO2, smoke and dust, and discharge of
domestic sewage, by a factor of at COD in China, 1995–2004. (Data on GDP and private cars from the National Bureau
least 1.3 (Han 2004). Should effec- of Statistics [1995–2004]; data on emissions of SO2, smoke and dust, and COD
tive countermeasures not be taken, discharge from SEPA [1995–2004].)
© The Ecological Society of America www.frontiersinecology.org
Environmental pollution and city clusters M Shao et al.
360 sions from motor vehicles will quadruple during the same Conclusions and suggested strategies
period, carbon monoxide and hydrocarbon levels will China’s economic growth over the past 20 years has
triple, and NOx and PM levels will also remain at high brought many benefits to its citizens, but at the cost of an
levels (CAE 2003). exponential increase in pollution over a relatively short
Increasing China’s already severe air pollution will sub- time (Liu and Diamond 2005). City clusters, where both
stantially increase the incidence of respiratory diseases economic activity and large populations are concentrated,
throughout the country, as air pollution is estimated to be suffer from extensive environmental degradation. China’s
the primary cause of nearly 50% of all respiratory ail- unique pollution complex, characterized not only by high
ments (Brunekreef and Holgate 2002). According to UN levels of primary pollutants but also by the interactions
Environmental Programme statistics (1999), soot and between them, and by their spread from source locations,
particle pollution from the burning of coal causes approx- leads to complicated regional problems. The large-scale
imately 50 000 deaths per year in China, while some watershed pollution and air pollution complex will con-
400 000 people suffer from chronic bronchitis annually in tinue to worsen if stringent measures to protect the envi-
the country’s 11 largest urban areas. The UN ronment are not taken soon.
Development Programme estimated that the death rate The realities of both economic losses and increasing
from lung cancer in severely polluted areas of China was mortality rates due to pollution have prompted a very
4.7–8.8-fold higher than in areas with good air quality serious consideration of future developments, and as
(UNDP 2002). Extrapolating from current emission lev- China enters into a new phase of development and eco-
els and trends, the World Bank estimated that by 2020 nomic prosperity, it finds itself at a crossroads. Will the
China will need to spend approximately US$390 billion country continue down the same road as in the past two
– or about 13% of projected GDP – to pay for the health- decades, or will environmental quality, energy efficiency,
care costs that will accrue solely from the burning of coal and the conservation of resources no longer be sacrificed
(World Bank 1997). at the altar of economic development?
A recent study on sustainable energy strategies for
China indicates that by means of improvements in energy Acknowledgements
efficiency and some restructuring, the projected quadru-
pling of the country’s economy would require only a dou- The authors would like to thank YH Zhuang, CS Kiang,
bling of current energy consumption rates (Zhou 2003). JY Fang, S Slanina, and SQ Zhang for their valuable com-
Implementing sustainable energy strategies will greatly ments and suggestions. Financial support was provided by
improve China’s energy efficiency by 2020, and CO2 the China National Key Basic Research Project
emissions, remaining high in terms of emissions per unit (#TG1999045700) and the China National Natural
GDP when compared with other countries, will be greatly Science Foundation (#40275037).
reduced as well.
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© The Ecological Society of America www.frontiersinecology.org
REVIEWS REVIEWS REVIEWS
362
Implementing China’s “Water Agenda 21”
Xiaoliu Yang1* and Jinwu Pang2
China’s per capita available water is only 2220 m3, about a quarter of the world average. As a result, China faces
an imbalance between the supply and demand of water for agricultural and general population use. Poor water
resource development, wasteful usage, and water pollution are all exacerbating the problem. Water-related
issues have seriously hampered economic development in China, especially in recent decades, while the coun-
try has undergone rapid economic growth. Implementing a sustainable water resource strategy is therefore
vital. To meet the goals of national economic reconstruction and development, and to solve the water shortage
problem, China’s “Water Agenda 21” was formulated in 1998. This paper focuses on the implementation of this
strategy and discusses China’s approach to solving its water-shortage problems in order to safeguard sustainable
socioeconomic development.
Front Ecol Environ 2006; 4(7): 362–368
water (surface plus groundwater) is 2.8 trillion m3 (MWR
C hina is a populous country with scarce resources and
relatively poor natural conditions. As a result of the
monsoon climate, rainfall occurs unevenly throughout
1992). China’s available water resources per capita are
only 2220 m3, about one quarter of the world average
the year. China’s annual precipitation is about 6.2 trillion (Qian and Zhang 2001).
m3, which corresponds to a depth of 648 mm over the There are about 2300 lakes (excluding seasonal lakes)
entire country (9.6 million km2; Liu 2002). Surface runoff in China, each with a water surface area larger than
and groundwater per annum are 2.7 trillion m3 and 830 1 km2. These include 12 large lakes, each with a surface
billion m3, respectively. The net total amount of available area greater than 1000 km2. The total surface area of all
China’s lakes is 72 000 km2 and the total storage capacity
is 709 billion m3, comprising 32% of the total fresh water
In a nutshell: storage capacity (Qian 1994). In addition, there are also
• China’s economic growth has been hindered by a shortage of
fresh water some 85 000 reservoirs which, in 1998, had a combined
• To balance water supply and demand and safeguard economic storage capacity of 458 billion m3, equivalent to 17% of
development, China’s “Water Agenda 21” was introduced in the total annual runoff (Gu 1999).
1998
• This aims to minimize water shortages and water pollution
and to meet the basic water needs of urban inhabitants, agri- Variability across the country
culture, and the environment
• Progress has been made in improving urban living standards, Correlation analysis (NIWA and IWHR 1998) suggests
balancing economic development and poverty alleviation, that China’s major river systems (Figure 1; Table 1) fall
securing food supplies, conserving soil and water, and protect- into five categories: (1) the Songhua–Liao watershed
ing ecosystems
• Nevertheless, further effort is required, particularly in inte-
group in the northeast; (2) the Hai-Luan watershed group,
grating water resources management and mobilizing the pri- Yellow watershed, and Huai watershed group in the north-
vate sector central region; (3) the Yangtze watershed, Pearl water-
shed, and southeast watershed group; (4) the southwest
watershed group; and (5) the inland watershed group.
Authors’ contact details are on p368) The major source of water to all the watersheds is rivers.
www.frontiersinecology.org © The Ecological Society of AmericaXL Yang and JW Pang China’s “Water Agenda 21”
Taking into account the duplication 363
between surface water and groundwater
flows, the groundwater contribution is
only significant on the plains, particularly
ao
in northern China (NIWA and IWHR
Li
a–
1998). Elsewhere in the country, ground-
hu
ng
water contribution is negligible. Table 2
So
gives the average water availability in
1993, relative to population density,
urbanization rate, income levels, and
arable land. The area south of the Yangtze
accounts for 81% of China’s water, but
only 54% of its population and 35% of the
arable land. Thus, per capita water avail-
ability for the area south of the Yangtze is
about four times greater than that for the
region to the north of the Yangtze, and the
per ha water availability for arable land
south of the Yangtze is about eight times
greater than that to the north of the river.
In general, less than 1700 m3 of water per
capita represents water stress, while less Figure 1. China's major river systems.
than 1000 m3 per capita is classified as a
water shortage. Water resources in the Hai-Luan watershed storage reservoirs and levees has resulted in a variable degree
group are as low as 245 m3 per capita, increasing to only 355 of protection from flooding, but huge areas of the country
m3 per capita when the net contribution of groundwater is remain vulnerable. Even the large cities may only be pro-
included. Availability in the Huai and Yellow River water- tected against a 40-year flood, with protection often
sheds in northern China is greater, but is still less than 1000 achieved at the expense of rural areas. Drought primarily
m3 per capita. affects northern and inland watersheds (Zhang 1997). They
In contrast, water is abundant in the south and southwest can be offset by making use of groundwater in dry years,
of the country. Inland watersheds account for about 35% of notably in the North China Plain, but this has only limited
China’s land area; although water availability per capita is potential when superimposed against general, and increas-
normally good, local desert communities face extreme ing, scarsity. In contrast, typhoons and tropical storms are
shortages. Water availability for irrigation is typically a lim- predominantly a feature of the southern coast, where they
iting factor in North China, but land rather than water is are relatively frequent during the early and late monsoon
the limiting factor in South China (Table 2). The situation months and can cause great damage.
in areas varies; average water availability tends to exceed
evaporation rates in inland watersheds, suggesting that Deterioration in quality
there is still potential for increased irrigation.
China’s water pollution problems are increasingly alarm-
Variability throughout the year ing. Table 4 shows that the discharge of wastewater and
Water availability varies greatly at different times of the Table 1. Distribution of water resources (MWR 1992)
year (Table 3). Annual variability is greater in the north (eg
the Songhua–Liao, Hai-Luan, and Yellow watersheds) than Watershed/watershed group Available water resources*
109 m3
in the south (eg the Yangtze and Pearl watersheds). There
can also be wide variability at the sub-watershed level; Songhua–Liao watershed group 193
typhoons and atmospheric depressions can dump huge Hai-Luan watershed group 42
quantities of water in the space of a few days, leading to sub- Yellow watershed 74
Huai watershed 96
stantial changes in river levels, followed by flooding. The
Yangtze watershed 961
relative stability of inland river flows is due to the continu- Pearl watershed 471
ous influence of snowmelt, which can mask differences at Southeast watershed group 259
the sub-watershed level. Southwest watershed group 585
This variability leads to alternating floods and droughts Inland watershed group 130
(Xu and Dai 2002). Historically, floods have been a serious Total China 2812
problem in China, so flood alleviation and control remain a * Excluding groundwater recharge estimated to be transformed under natural con-
ditions into river discharge.
major concern in most regions (Li 1999). Construction of
© The Ecological Society of America www.frontiersinecology.orgChina’s “Water Agenda 21” XL Yang and JW Pang
364 Table 2. Water resource indicators for major watersheds/watershed groups in 1993 (NIWA and IWHR 1998)
Urban GDP per Arable Available water Unit water
Watershed (W)/ Population rate capita land resources * availability
watershed group (WG) 106 % index 106 ha 109 m3 m3 per capita m3/ha–1
Songhua–Liao WG 113.2 41 107 19.5 193 1705 9900
Hai-Luan WG 117.6 24 113 10.8 42 355 3900
Yellow W 99.2 22 84 12.4 74 746 5970
Huai W 190.5 17 85 14.7 96 504 6800
Yangtze W 402.5 22 93 22.9 961 2390 41 950
Pearl W 141.5 28 130 6.5 471 3330 7250
Southeast WG 65.1 24 135 2.4 259 3980 107 900
Southwest WG 18.3 11 32 1.7 585 31 970 344 100
Inland WG 24.7 37 91 5.4 130 5265 24 050
Total China 1172.6 24 100 96.4 2812 2400 29 150
Notes: * Excluding groundwater recharge estimated to be transformed under natural conditions into river discharge
** Equivalent of available water distributed uniformly over arable land
pollutants has increased since 2000; the total amount of industrial and domestic use and environmental needs. In
discharged wastewater in 2004 was 48.24 billion tons, of the northern part of the country and the inland water-
which 22.11 billion tons was discharged industrial efflu- sheds, overexploitation of water resources from some
ent and 26.13 billion tons was domestic sewage. At the rivers has led to successive drying of river courses, partic-
same time, the chemical oxygen demand (COD) dis- ularly in the lower reaches. In some regions, overuse of
charged reached 13.39 million tons, of which 38% came groundwater has caused serious regional declines in the
from industrial sources and 62% from domestic house- groundwater table, creating a series of ecological prob-
holds. A total of 1.33 million tons of ammonia–nitrogen lems, including large-scale land subsidence, disappear-
was discharged, of which 33% came from industry and ance of wetlands, and environmental deterioration (Liu
67% from domestic sources. Moreover, some untreated or and Chen 2001). In addition, the problems of water pol-
poorly treated wastewater and sewage are discharged lution and soil and water loss are very serious, severely
directly into rivers, lakes, and reservoirs, resulting in dif- affecting efforts to harmonize population growth, natural
ferent levels of pollution. Some freshwater lakes are expe- resources development, environmental protection, and
riencing severe eutrophication and shallow groundwater the preservation of ecosystem services. This has ham-
has also been polluted in some areas. Water pollution has pered China’s socioeconomic development (Wang 2002).
exacerbated environmental degradation and further China needs to implement a sustainable water resource
aggravated the imbalance between supply and demand, development strategy that will strengthen its water infra-
threatening sustainable use of water resources. structure, protect ecosystems, conserve and protect its
water resources, control water pollution, and promote the
Formulation of China’s “Water Agenda 21” sustainable use of water resources throughout the country.
In the 1990s, the Central Government promulgated
As mentioned above, China is subject to severe floods China’s Agenda 21 (GPRC 1994). As a result, a number
and droughts; this leads to water shortages and a serious of studies on water were conducted, including reports on
imbalance between water supply and the requirements for sustainable water resource development (Liu and He
Table 3. Variability in river runoff (MWR 1992)
Mean annual Annual runoff at different relative values (mean
Watershed (W)/ runoff annual runoff = 100)
watershed group (WG) mm 109 m3 20% 50% 75% 95%
Songhua–Liao WG 132 165 127 96 75 52
Hai-Luan WG 91 29 132 93 69 45
Yellow W 83 74 116 97 85 72
Huai W 225 66 135 93 67 40
Yangtze W 526 951 111 99 91 80
Pearl W 807 468 115 99 88 72
Southeast WG 1066 256 120 98 82 63
Southwest WG 688 585 110 100 92 81
Inland WG 34 116 108 99 93 85
Total China 284 2711 107 100 94 87
www.frontiersinecology.org © The Ecological Society of AmericaXL Yang and JW Pang China’s “Water Agenda 21”
Table 4. Discharged wastewater and major pollutants in China’s rivers (SEPA 2005) 365
Amount of wastewater COD Ammonia–nitrogen
Year (billion tons) (million tons) (million tons)
Total Industrial Domestic Total Industrial Domestic Total Industrial Domestic
2000 41.51 19.42 22.09 14.450 7.045 7.405 na na na
2001 43.29 20.26 23.03 14.048 6.075 7.973 1.255 0.413 0.839
2002 43.95 20.72 23.23 13.669 5.840 7.829 1.288 0.421 0.867
2003 46.00 21.24 24.76 13.336 5.119 8.217 1.297 0.404 0.893
2004 48.24 22.11 26.13 13.392 5.097 8.295 1.330 0.422 0.908
na = not available
1996), relationships between water, the economy, and and demand (NIWA and IWHR 1998) was developed.
society (Chen 1997; Huang 1997), water financing (An The plan emphasized better allocation, more efficient use,
1997), and water conservation (Jiang 1997). Based on and stronger protection of water resources. The imple-
this work, China’s Water Agenda 21 (MWR 1998) was mentation of this plan helped to mitigate water shortages
formulated. Priority was given to addressing water short- in north China; for instance, during the drought of 2000,
age and pollution issues, and to meeting the basic water such integrated water resource management prevented
needs of urban inhabitants, industry, agriculture, and the lower reaches of the Yellow River from drying up at
ecosystems. Water Agenda 21 outlined policies for sus- certain times of the year, as had previously occurred.
tainable water resource development and listed key In 2001, the Central Government placed a high priority
actions and projects. on working towards sustainable economic and social
Ever since the period covered by the national Ninth development (The State Council of GPRC 2001).
Five-year Plan (1996–2000), sustainability has become Recognizing that sustainable use of water resources is a
the basic guiding principle for socioeconomic develop- strategic issue in China’s development, the plan called for
ment in China. As a result, a sustainable water resource the implementation of vigorous measures to strengthen
development strategy, as outlined in Water Agenda 21 the water infrastructures, and strongly encouraged protec-
(MWR 1998), has been implemented. This has led to tion and sustainable management of water resources. In
increased control and development of water resources in urban and associated industrial and agricultural develop-
the country’s major watersheds, and an improvement in ment, the carrying capacity of water resources and effi-
the potable water supply and sanitary conditions in ciency of water use had to be taken into consideration.
impoverished areas. More emphasis has been placed on The plan also called for various water-saving technologies
the improvement of irrigation systems for the purpose of and measures to be comprehensively implemented, and
conserving water, on ecofriendly construction with regard for the development of low water consumption industries.
to soil and water conservation, on the prevention and Finally, the plan encouraged the general public to become
control of water pollution, and on comprehensive envi- much more aware of the need for water conservation, and
ronmental improvement. The water infrastructure in the recommended that traditional methods for conserving
western part of China has been strengthened. water be replaced with new technologies.
In line with China’s Water Agenda 21, action plans
were formulated in the Yangtze watershed (Yangtze River Actions and progress towards sustainable water use
Commission 1998), the Huai watershed (Huai River
Commission 1998), the Yellow watershed (Yellow River
Urbanization and living standards
Commission 1998), the Hai and Luan watersheds (Hai
River Commission 1998), Taihu Lake (Taihu Lake Since the 1990s, the process of urbanization and the con-
Management Bureau 1998), the Songhua and Liao water- struction of new urban facilities has continued to acceler-
sheds (Song and Liao Rivers Commission 1998), and the ate. From 1992 to 2000, the populations in cities and
Pearl watershed (Pearl River Commission 1998). These towns in China increased by 132 million people and the
plans have guided water resource development in each of rate of urbanization increased from 27.63% to 36.09%
these watersheds. (NBS, 1992, 2000). This has been accompanied by water
shortages in cities and towns, flooding, and drainage and
A sustainable water strategy to support national aquatic environmental problems. Four hundred of the
socioeconomic development 668 cities in China suffer from some degree of water
shortage (MWR 2002). Of these, 108 cities have serious
In 1995, the Central Government decided to further water shortages, of the order of about 6 billion m3 annu-
strengthen water resource development (The State ally. Six hundred and twenty-five cities are subject to
Council of GPRC 1996). Consequently, a medium- and floods and waterlogging, due to inadequate flood control
long-term national plan that would balance water supply measures and poor drainage systems (MWR 2002).
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