China distribution of water resources and irrigation and drainage watersheds zoning

The Irrigation Requirement Index of Three Irrigation Zones in China

Distribution of water resources and irrigation and drainage zoning in different river basins in China:

9613 that the total water resources in the area (billion cubic meters)

The red line represents the annual precipitation isobath

Chinese irrigation drainage belt

In the figure, 1 is the year-round irrigation area, and the irrigation requirement index is 0.6 to 0.9

In the figure, 2 is the unstable irrigation area: the irrigation requirement index is 0.2-0.7

In the figure, 3 indicates that the irrigation area is irrigated: the irrigation index is 0.1 to 0.5

Irrigation need index: the ratio of water required for irrigation to crop water requirement

Number of Water Resources in China

Total Water Resources in China

Precipitation

In 2008, the average annual precipitation reached 654.8mm, equivalent to 6.2 trillion cubic meters of precipitation, 1.9% higher than the annual average (multi-year average). From the water resources zoning, the average precipitation of the six water resources of the Songhua River, Liaohe River, [Yellow River, Huaihe River and the northwestern rivers] is 322.6 mm, The average precipitation in the Yangtze River (including the Taihu Lake), the southeast rivers, the Zhujiang River and the southwest rivers is 1244.3mm, which is more than the annual average. 3.7%. There are 14 provinces (autonomous regions, municipalities directly under the central government) with precipitation higher than the annual average in 31 provinces, of which about 20% are in Guangdong and Hainan; 17 provinces (autonomous regions and autonomous regions), Of which less than 10% of Ningxia and Heilongjiang.

Surface water resources

In 2008, the total amount of surface water resources in China was 2,637. 7 billion cubic meters, equivalent to the annual runoff of 278.6 mm, 1.2% less than the annual average. From the perspective of water resources, the amount of surface water resources in the six districts in the north is 16% less than the normal value and 1.7% in the southern four districts. Among the 31 provinces, there are 12 provinces (autonomous regions and municipalities) with more surface water resources than normal, 19 provinces (autonomous regions and municipalities) with less than normal value, among which Hainan, Tianjin and Shanghai , Guangdong, Guangxi, the partial extent of 36% to 20%, Heilongjiang, Hebei, Shanxi, Inner Mongolia, Gansu, Ningxia less degree of 50% to 30%.

In 2008, the amount of water flowing into the territory of China from outside the country was 23.3 billion cubic meters. The amount of water flowing out of the country was 605. 7 billion cubic meters. The amount of water flowing into the international border rivers was 64.7 billion cubic meters. The amount of water entering the country was 16110 billion cubic meters.

Groundwater Resources

In 2008 the amount of groundwater resources in the region of 2g / L or less was 812. 2 billion cubic meters, of which the groundwater resources in the plain area was 173. 6 billion cubic meters, the amount of underground water in the hilly area was 668.3 billion cubic meters, The recalculation of groundwater resources between hilly areas was 29.7 billion cubic meters. In 2008, the total recharge of groundwater in the plain areas of China was 180. 6 billion cubic meters, of which the total recharge of groundwater in the six areas in the north was 147. 3 billion cubic meters, accounting for 81.6% of the total supply. The recharge amount of surface water infiltration, precipitation infiltration recharge, piedmont side infiltration recharge and well irrigation return supply accounted for 36. 3%, 51.2%, 7.9% and 4.6% respectively in the northern plain area.

Total water resources

In 2008, the total amount of water resources in China was 2,743. 4 billion cubic meters, which was 1% less than the normal value. Groundwater and surface water resources do not repeat the amount of 105. 7 billion cubic meters, accounting for 13% of groundwater resources, that is, 87% of groundwater resources and surface water resources to repeat. The total water resources in the six districts in the north are 460. 1 billion cubic meters, 12.5% less than the annual average, accounting for 16.8% of the total. The total water resources in the four southern regions are 22834 billion cubic meters, 1.7% 83.2%. The total water resources accounted for 44.2% of the total rainfall, the average water production per square kilometer 29 million cubic meters. From the total point of view, according to the latest statistics in 2009, China's total water resources of about 2812.4 billion cubic meters, ranking sixth in the world. The top five are Brazil, Russia, Canada, the United States and Indonesia.

The map comes from China's physical geography atlas in China, the distribution of water resources and irrigation and drainage zoning