Xi-jie Chen,Long-feng Wng,Li-qiong Ji,Ting Ji

a Development and Research Center of China Geological Survey, Beijing 100037, China

b China Institute of Geo-Environment Monitoring, China Geological Survey, Beijing 100081, China

Ministry of Water Resources of China recently released the Bulletin of China Water Resources in 2020 which points out the national precipitation and total water resources are significantly higher than the multi-year averages (refer to the average during 1956-2000),and the storage of large and medium-sized reservoirs and lakes was generally stable in 2020.The total amount of national water consumption in 2020 has decreased compared with 2019,the water use efficiency has been further improved,and the water use structure has been continuously optimized.

1.Precipitation

In 2020,the national average annual precipitation is 706.5 mm,which is 10.0% more than the multi-year average and 8.5% more than 2019.The comparison of the first-level water resources area in 2020 with the data of 2019 and the multiyear average is shown in Table 1.

2.Surface water resources and groundwater resources

The amount of surface water resources is 3040.7×109m3,equivalent to an annual runoff depth of 321.1 mm,which is 13.9% higher than the multi-year average and 8.6% higher than in 2019.

The amount of groundwater resources (salinity ≤ 2g/L) is 85855.35×109m3,which is 6.1% higher than the multi-year average.Among them,the amount of groundwater resources in the plain area is 202.24×109m3,the amount of groundwater resources in the hilly area is 683.61×109m3,and the amount of repeated calculations between the plain area and the hilly area is 30.5×109m3.

The total recharge of shallow groundwater in the plains across China is 209.32×109m3.The statistical area of shallow groundwater in the plains of the Southern four water areas[ the Yangtze River (including the Taihu area),the Southeastern rivers area,the Zhujiang area,and the Southwestern rivers area] accounted for 9% of the plain area of China,and the total groundwater recharge was 38.58×109m3.The Northern six water areas (Songhuajiang area,Liaohe area,Haihe area,Yellow River area,Huaihe area,and Northwest rivers area) account for 91% of the area,and the total groundwater recharge is 170.74×109m3.Among them,Songhuajiang area is 40.16×109m3,Liaohe area is 12.91×109m3,Haihe area is 18.57×109m3,Yellow River area is 16.65×109m3,Huaihe area is 34.14×109m3,and Northwest rivers area is 48.31×109m3(Fig.1).

Fig.1.Distribution map of China's main first-level water resources area.

3.Total water resources

In 2020,the total amount of water resources in China is 3160.52×109m3,which is 14.0% more than the multi-year average and 8.8% more than in 2019.Among them,the amount of surface water resources is 3040.7×109m3,the amount of groundwater resources is 855.35×109m3,and the amount of groundwater and surface water resources is 119.82×109m3.The total amount of water resources in China accounts for 47.2% of the total precipitation,and the average water production per unit area is 334000 m3/km2.The total amount of water resources in each first-level water resource area in 2020 is shown in Table 2.

Table 1.The comparison of the first-level water resources area in 2020 with the data of 2019 and the multi-year average.

Table 2.The amount of water resources in each first-level water resources area in 2020,China.

Fig.2 shows the change process of the total amount of water resources in China from 1956 to 2020.Compared with the multi-year average,the total amount of water resources in China has not changed much in different years,with an increase of 3.9% from 1990 to 1999,a decrease of 3.9% from 2000 to 2009,and an increase of 3.7% since 2010.Compared with the multi-year average,the total amount of water resources in the Southern four water areas were 4.8% higher in 1990-1999,3.2% lower in 2000-2009,and 3.2% higher since 2010; the total amount of water resources in the Northern six water areas were close to the multi-year average from 1990 to 1999 and were 6.9% lower in 2000-2009.Since 2010,it has increased by 5.8%.

Fig.2.The change of national water resources from 1956 to 2020 in China.

4.Water storage dynamics

The total water storage of 705 large-scale reservoirs and 3729 medium-sized reservoirs nationwide increased by 23.75×109m3from the beginning of the year.The total water storage of 62 lakes at the end of the year increased by 4.75×109m3from the beginning of the year.The shallow groundwater levels in the Northeast Plain,the Huang-Huai-Hai Plain,and the Middle and Lower Yangtze Plains have generally risen,while the plains and basins in Shanxi and the Northwest China have declined slightly.

5.Development and utilization of water resources

The total water supply and total water consumption in China are both 581.29×109m3,which is 20.83×109m3less than in 2019 due to factors such as the COVID-19 epidemic and abundant precipitation.Among them,surface water supply is 479.23 ×109m3,groundwater supply is 89.25×109m3,and other water sources are 12.81×109m3; domestic water is 86.31 ×109m3,industrial water is 103.04×109m3,agricultural water is 361.24×109m3,and artificial ecological environment replenishment is 30.70×109m3.The total water consumption nationwide is 314.17×109m3.

The national per capita comprehensive water consumption is 412 m3,and the water consumption per 10000 CNY of GDP (current year’s price) is 57.2 m3.The actual irrigated water consumption per mu (mu is a Chinese municipal land area unit,about 666.67 m2) of arable land is 356 m3,the effective utilization coefficient of farmland irrigation water is 0.565,the water consumption per 10000 CNY of industrial added value (the current price) is 32.9 m3,the urban per capita domestic water consumption (including public water) is 207 L/d,and the per capita domestic water consumption of rural residents,the amount is 100 L/d.Calculated at comparable prices,water consumption per 10000 CNY of GDP and water consumption per 10000 CNY of industrial added value decreased by 5.6% and 17.4%,respectively,compared with 2019.

Source from Ministry of Water Resources of the People’s Republic of China (www.mwr.gov.cn/sj/tjgb/szygb/202107/t20210709_1528208.html.