2.2 Surface Water Resources

The quantity of surface water resources in China was 2,690.08 billion m3 in 2015,equivalent to 284.1 mm in depth,which is 0.7% more than normal and 2.5% more than that in 2014.

In terms of water resources regions,the quantity of surface water resources in the Northern Six Regions in 2015 was 383.62 billion m3,equivalent to 63.3 mm in depth,12.4% less than normal and 0.8% more than that in 2014.That in the Southern Four Regions was 2,306.46 billion m3,equivalent to 675.8 mm in depth,3.3% more than normal and 2.7% more than that in 2014.Among the ten Class I WRRs,the Southeast Rivers,Pearl,Yangtze and Northwest Rivers had an annual quantity more than normal,in which the Southeast Rivers and Pearl had an annual quantity 27.8% and 13.1% more than normal,respectively;and the other regions had an annual quantity less than normal,in which the Haihe,Liaohe and Yellow had an annual quantity 49.8%,44.5% and 28.9% less than normal,respectively.Compared with 2014,the Yellow,Songhua and Southwest Rivers experienced decreases of surface water resources of 19.3%,8.8% and 8.0%,respectively;and the other regions experienced increase to a varying extent,in which Liaohe and Huaihe experienced increases of 35.5% and 19.0%,respectively.See Table 3 for comparison of the 2015 annual natural runoff with the 2014 annual natural runoff and normal by Class I WRR.

In terms of administrative regions,11 PARs had a quantity of surface water resources more than normal,in which Shanghai and Jiangsu had a quantity 127.2% and 74.8% more than normal,respectively;Heilongjiang had a quantity close to normal;and 19 had a quantity less than normal,in which Hebei,Shandong,Liaoning and Beijing had a quantity over 40% less than normal.Table 4 and Figure 5 show comparison of the 2015 natural runoff with the 2014 natural runoff and normal by PAR.

In 2015,21.36 billion m3 of water flowed from abroad into China;513.97 billion m3 of water flowed from China to abroad;and 106.12 billion m3 of water flowed from China into the border rivers between China and other countries.

Table 3 Comparison of 2015 natural runoff with 2014 natural runoff and normal by Class I WRR

In the whole country,the total quantity of water flowing into the sea in 2015 was 1,760.09 billion m3,or 127.12 billion m3 more than that in 2014,in which 5.88 billion m3 was from the Liaohe,2.84 billion m3 from the Haihe,12.66 billion m3 from the Yellow,38.91 billion m3 from the Huaihe,965.80 billion m3 from the Yangtze,236.25 billion m3 from the Southeast Rivers,and 497.75 billion m3 from the Pearl.Water flowing into the sea accounted for about 26% of the quantity of local surface water resources in the Liaohe,29% in the Yellow,64% in the Huaihe and over 90% in the Pearl,Yangtze and Southeast Rivers.

Table 4 Comparison of 2015 natural runoff with 2014 natural runoff and normal by PAR

Figure 5 Comparison of 2015 natural runoff with normal by PAR