1　Quantity of Water Resources

1.1　Precipitation

The average annual precipitation reached 730.0 mm in depth in 2016,13.6% more than normal and 10.5% more than that in 2015.The regional distribution of the 2016 precipitation is shown in Figure 1,and that of 2016 is revealed in Figure 2.The variation of annual precipitation from 1956 to 2016 is demonstrated in Figure 3.

The ten first-class water resources regions （Class I WRRs） had a greater average annual precipitation than normal,among which the Rivers in the Southeast and the Rivers in the Northwest had an annual precipitation 35.5% and 28.0% more than normal,respectively.Compared with 2015,the ten Class I WRRs had an increased precipitation to a varying extent,in which the Liaohe and the Rivers in the Northwest had an annual precipitation 25.9% and 21.2% more than that in 2015,respectively.Table 1 shows the comparison of the precipitation in 2016 with the 2015 precipitation and normal by Class I WRRs.

Among the provincial administrative regions （PARs）,27 provinces,autonomous regions and municipalities directly under the central government had an annual precipitation more than normal,in which Fujian Province,Xinjiang Uygur Autonomous Region,Shanghai City,and Jiangsu Province had a quantity over 40% more than normal,Sichuan,Shaanxi,Gansu,and Shandong Provinces had a quantity 3% to 6% less than normal.See Table 2 for comparison of the 2016 precipitation with the 2015 precipitation and normal by PARs.Refer to Figure 4 for monthly precipitation in 2016 as well as a normal year at some precipitation observation stations.

Figure 1　Isopleth map of annual precipitation in China,in 2016 (Unit:mm)

Figure 2　Anomaly map of annual precipitation in China in 2016 (%)

Figure 3　Variation of annual precipitation in China from 1956 to 2016

Table 1　Comparison of 2016 precipitation with 2015 precipitation and normal by Class I WRRs

Notes:1.The Northern Six Regions are the Songhua,Liaohe,Haihe,Yellow,Huaihe and Rivers in the Northwest;
2.The Southern Four Regions are the Yangtze （including Taihu Lake）,Rivers in the Southeast,Pearl and Rivers in the Southwest;
3.The calculation area of the Rivers in the Northwest accounts for 55.5% of the total area of Northern Six Regions,and that of the Yangtze River accounts for 52.2% of the total area of the Southern Four Regions.

Table 2　Comparison of 2016 precipitation with 2015 precipitation and normal by PARs

Figure 4(1)　Monthly precipitation in 2016 and a normal year at some precipitation observation stations

Figure 4(2)　Monthly precipitation in 2016 and a normal year at some precipitation observation stations