| Water
Resources of China
#
#China
is situated in the southeastern part of the Eurasian Continent. The distribution
of precipitation and water resources in this country varies largely in
both time and space due to the influence &the varied topographic features
and monsoon climate. Thousands of years of struggle against drought and
waterlogging has formed one important theme of the Chinese civilization.
Since the foundation of the People's Republic of China, the government
has attached great importance to water conservancy and has constructed
a large number of water conservancy projects which contributed immensely
to keeping 1 billion Chinese people away from famine: common floods thus
effectively controlled, 0.7 billion mu of cultivated land constantly irrigated
and urban domestic and industrial demand of water, to some extent, roughly
satisfied.
# #The
total amount of water resources in China ranks the country sixth in the
world.
However, the amount of water resources per capita and per unit cultivated
land is far less than the world average for the country's dense population
and vast territory. Furthermore, the distribution of these spare water
resources is uneven both temporally and spatially and does not coordinate
with the distribution of population, cultivated land, and mineral resources.
As a consequence, water is often found such an inharmonious factor with
economic development that would hardly leave a balanced demand-and-supply
to any regions. The situation of less supply than demand grows more and
more serious in the places short &water, like in North China and the
southern part of Northeast China. For the vast Northwest, the restraint
of poor water resources will certainly enable a lagging economy after
it has been somewhat developed. As for the Yangtze River Basin and its
southern regions where water resources are relatively affluent, unsatisfied
water supply also occurs in some areas owing
to insufficiency of regulation and control projects.
Not only water consumption but as well wastewater discharge have been
increasing with the economic development. The crisis of water supply is
aggravated by the decrease of clean water sources most of which have been
polluted. It still remains as an arduous task to ensure the modernization
process in China against the risks of floods and the shortage of clean
water sources. The fundamental approaches to the problem of water resources
are (1) strengthening and improving theexisting water conservancy projects
and erecting new projects to improve the ability of flood control and
water supply; (2) tightening up on wastewater treatment to protect water
sources; (3) enhancing water saving and multipurpose use of water resources
to raise the use value of water; and (4) enforcing water resources management.
#
#The
long term mean annual precipitation of the country is 648 mm, of which
44% forms the river runoff, 56% is lost in the evapotranspiration from
surface waterbodies, plants and soils and the phreatic water evaporation.
The long term mean annual river runoffdepth for the whole country is 284
mm, of which 25% is supplied by groundwater, equivalent to 71 mm of water
depth. The long term mean annual volume of evaporation and transpiration
for the country is 364 mm, of which only 3% is the phreatie water evaporation
in the fresh water areas of the plains, is usable by means of groundwater
withdrawal. The long term mean annual of water yield (i.e. the gross water
resources) in the whole country is 2812.4 billion m3, equivalent to water
depth of 295 mm, constituting 45% of the total precipitation of the country,
of which the base flow and the phreatic water evaporation in the fresh
water areas of the plains is comparatively easily exploited, its volume
being about 780 billion ms, 28% of the gross water resources; the remaining
72% being the volume of surface runoff, varying widely within a year and
from year to year, and being able to be controlled and utilized only when
regulation facilities are provided.
#
#The
values of the water budget elements and their relations are obviously
different for different regions. For the 4 southern catchment regions,
the mean annual precipitation is I 204 mm, the mean annual runoff depth
is 650 mm, being 1.9 and 2.3 times as large as the mean values for the
whole country respectively; the mean depth of water yield is 654 mm, 2.2
times as large as the mean
value for the country. For the 6 northern major regions (including the
Ertix River), the mean annual precipitation is only 330 mm, the annual
runoff depth, 74 mm, being 51% and 26% the mean values for the country;
the mean depth of water yield is 88 mm, 30% the mean value for the country.
But the storage capacity of the aquifers in the northern plains is larger
than that in the southern plains, so the values of (Rg + Eg)/W are all
larger for the 6 northern regions than those for the 4 southern regions
(see Table 5-3).
#
#The
region of inland rivers is the driest area in the country, the mean annual
precipitation there is only 154 mm, the annual runoff depth, only 32 mm,
owing to the storage effect of glaciers and aquifers, the base flow ratio
(Rg/R) and the value of (Rg+Eg)/W are the largest of all the ten regions,
therefore, the amount of exploitable and utilizable water occupies a large
part of the gross water resources. |

#
#China
Basics
##History
of China
##Map
of China
##Provinces
& Cities
##Art
& Craft
##Population
##Mountains
##Rivers
##Lakes
##Seas&
Deserts
##Glacials
##Climamte
of China
##Vegetation
##Pedogeography
##Grassland
##Water
Resources
Related Books
Water Resources Development in China
Remote Sensing in Water Resources
Water Resources Assessment for China
More...
|