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1 Physical Settings and Water Challenges
China, the Yangtze River, the Pearl River, and the rivers in Southeast China, with
Class I–III between 82 and 97%. The water quality in the Hai River, Yellow River,
Huai River, Liao River, and Songhua River is worse, with Class I–III between 38.9
and 68.5%. The data from 544 provincial boundary stations in 2016 shows that 15.8
and 17.1% were rated Class IV–V and worse than Class V, respectively. Of 6,270
water function zones assessed, only 58.7% met the water quality targets (MWR
2017).
Algae outbreaks occur in many lakes in China. The water-plentiful regions, such
as the Pearl River Delta and the Yangtze River Delta, suffer from water shortages
caused by water pollution. The quality of groundwater is also deteriorating. About
54% of the groundwater in the plain areas does not meet the water quality standards
for domestic use.
In some basins and regions, water pollution has extended from the tributary to
the mainstream, from urban areas to rural areas, from the surface to underground,
and from the land to the sea. Water pollution not only exacerbates the shortage of
water resources but also directly threatens the safety of drinking water and population
health, as well as affecting industrial and agricultural production and the safety of
crops, resulting in huge economic losses.
1.5.3 Increasing Water Ecosystem Degradation
Water resource development and use has greatly exceeded the amount of available
water resources in some regions. This over-exploitation has led to rivers drying up,
lakes shrinking, and land subsidence. In North China, the fact that “rivers are all
dry, water is dirty, wetlands disappear, groundwater is depleted” poses a potential
threat to ecological and economic security. More than 90 rivers across the country,
including major rivers such as the Yellow River and the Liao River, have begun to dry
up, resulting in serious problems in river function. Compared with the early 1950s,
the national lake area has decreased by 15%, the number of lakes in the middle and
lower reaches of the Yangtze River has been reduced by more than 50%, and natural
wetland area has decreased by 26%. The reduction and loss of lakes and natural
wetlands decrease the capacity of water resources to self-regulate and self-purify,
exacerbate flood damage, and deteriorate water quality.
The country has formed 164 groundwater overdraft areas with a total area of
190,000 km
2 , with average annual groundwater overdraft volume exceeding 10 km
3 .
Land subsidence and sea water intrusion have occurred in some areas. The land
subsidence area has reached 64,000 km
2 ; more than 50 cities are threatened by
serious land subsidence.
1 Physical Settings and Water Challenges
China, the Yangtze River, the Pearl River, and the rivers in Southeast China, with
Class I–III between 82 and 97%. The water quality in the Hai River, Yellow River,
Huai River, Liao River, and Songhua River is worse, with Class I–III between 38.9
and 68.5%. The data from 544 provincial boundary stations in 2016 shows that 15.8
and 17.1% were rated Class IV–V and worse than Class V, respectively. Of 6,270
water function zones assessed, only 58.7% met the water quality targets (MWR
2017).
Algae outbreaks occur in many lakes in China. The water-plentiful regions, such
as the Pearl River Delta and the Yangtze River Delta, suffer from water shortages
caused by water pollution. The quality of groundwater is also deteriorating. About
54% of the groundwater in the plain areas does not meet the water quality standards
for domestic use.
In some basins and regions, water pollution has extended from the tributary to
the mainstream, from urban areas to rural areas, from the surface to underground,
and from the land to the sea. Water pollution not only exacerbates the shortage of
water resources but also directly threatens the safety of drinking water and population
health, as well as affecting industrial and agricultural production and the safety of
crops, resulting in huge economic losses.
1.5.3 Increasing Water Ecosystem Degradation
Water resource development and use has greatly exceeded the amount of available
water resources in some regions. This over-exploitation has led to rivers drying up,
lakes shrinking, and land subsidence. In North China, the fact that “rivers are all
dry, water is dirty, wetlands disappear, groundwater is depleted” poses a potential
threat to ecological and economic security. More than 90 rivers across the country,
including major rivers such as the Yellow River and the Liao River, have begun to dry
up, resulting in serious problems in river function. Compared with the early 1950s,
the national lake area has decreased by 15%, the number of lakes in the middle and
lower reaches of the Yangtze River has been reduced by more than 50%, and natural
wetland area has decreased by 26%. The reduction and loss of lakes and natural
wetlands decrease the capacity of water resources to self-regulate and self-purify,
exacerbate flood damage, and deteriorate water quality.
The country has formed 164 groundwater overdraft areas with a total area of
190,000 km
2 , with average annual groundwater overdraft volume exceeding 10 km
3 .
Land subsidence and sea water intrusion have occurred in some areas. The land
subsidence area has reached 64,000 km
2 ; more than 50 cities are threatened by
serious land subsidence.