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
##Provinces & Cities
##Art & Craft
##Population
##Mountains
##Rivers
##Lakes
##Seas& Deserts
##Glacials
##Climamte of China
##Vegetation
##Pedogeography
##Grassland
##Water Resources

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