2 Quantity of Water Resources

2.1 Precipitation

China received an average annual precipitation of 668.0 mm in 2012，equivalent to a quantity of 6，515.01 billion m³，which was 7.1%more than normal，and 18.2%more than that in 2011.See Figure 1 for variation of annual precipitation in China between 1956 and 2012.The regional distribution of the 2012 annual precipitation is shown in Figure 2 and that of the difference between the 2012 annual precipitation and normal is shown in Figure 3.

Figure 1 Variation of annual precipitation in China，1956～2012

Among the first-class water resources regions（Class Ⅰ WRR），the Songhua River，the Liaohe River，the Haihe River，the Yellow River，the Huaihe River and Northwest Rivers（Northern Six Regions）had an average annual precipitation of 364.2 mm，which was 11.0%more than normal and 13.0%less than that in 2011.The Yangtze River（includeing the Taihu Lake），Southeast Rivers，the Pearl River and Southwest Rivers（Southern Four Regions）had an average annual precipitation of 1，262.7 mm，5.2%more than normal and 21.0%more than that in 2011.Among the ten Class Ⅰ WRRs，except that the Huaihe River and Southwest Rivers had an annual precipitation less than normal，all regions had an annual precipitation more than normal to a varying extent，in which the Liaohe and Southeast Rivers had an annual precipitation 28.9%and 25.8%more than normal，respectively.As compared with 2011，except that the Huaihe and Southwest Rivers had an annual precipitation less than normal，all the other regions had a increased annual precipitation to a varying extent，in which Southeast Rivers and the Liaohe River had an annual precipitation 49.9%and 49.0%more，respectively.Table 1 and Figure 4 show the 2012 precipitation and comparison with 2011 and normal in Class Ⅰ WRR.

Fiqure 2 Isohyetal map of annual precipitation in China，2012（Unit：mm）

Figure 3 Anomaly map of annual precipitation in China，2012（Unit：%）

Table 1 Precipitation and comparison with 2011 and normal in Class Ⅰ WRR，2012

Figure 4 Precipitation and comparison with normal in Class Ⅰ WRR，2012

Note：The Yangtze River includes the Taihu Lake basin.

Among the Provincial Administrative Regions（PAR），11 PARs in eastern China（eastern China）had an average annual precipitation of 1，281.3 mm，which was 15.9%more than normal；8 PARs in central China（central China）had an average annual precipitation of 1，003.7 mm，9.6%more than normal；and 12 PARs in western China（western China）had an average annual precipitation of 516.0 mm，2.9%more than normal.Among the 31 PARs，20 had an annual precipitation more than normal，in which Tianjin，Liaoning，Jiangxi and Zhejiang had a quantity over 30%more than normal；Shanxi，Anhui and Shaanxi had a quantity close to normal；and 8 had a quantity less than normal，in which Henan had a quantity 21.5%less than normal.See Table 2 and Figure 5 for the 2012 precipitation and comparison with 2011 and normal in PAR.

Table 2 Precipitation and comparison with 2011 and normal in PAR，2012

Figure 5 Precipitation and comparison with 2011 and normal in PAR，2012