استفاده از آب پایدار و قیمت سایه ای آب در صنعت شهری چین Sustainable water use and water shadow price in China’s urban industry

1. Introduction China’s urban industrial economy has achieved remarkable progress since the reform and opening up policy in late 1970s. As an important input in the industrial production, the amount of industrial water consumption has shown an obvious rising trend. As shown in Fig. 1, the total amount of industrial water in China shows an upward trend in 2004–2012, and it is as high as 142.2 billion tons in 2012. The water use efficiency in China’s industry sector is relatively low, and millions of tons of water is wasted in the process of industrial production in recent years (Deng et al., 2016). On the other hand, water pollution caused by industrial production has posed great threat to people’s health. We can find in Fig. 1 that the amount of industrial wastewater discharge is up to 24.66  billion tons, and it shows a slight decrease trend since 2007. Specifically, in 2012, the amounts of chemical oxygen demand (COD) and ammonia nitrogen (AN) in industrial wastewater are 3.38 and 2.64 million tons, respectively. Unfortunately, most of them are directly discharged into the water supply sources, which made almost each province in China experience accidents of river and lake pollution. Itis well known that China is a nation with a serious water shortage problem, and the amount of water available per capita is only about a quarter of the world average level in 2012 (Wang et al., 2015). The awful waste of water and frequent water pollution incidents has made the problem of water shortage more severe, causing great negative impacts onsocial andeconomicdevelopment(Cheng et al., 2009; Xie and Wang., 2015a; Cai et al., 2016). Therefore, improving the water use efficiency and abating water pollution are critical for sustainable water use in China (Gao et al., 2014; Liu et al., 2014; Hu et al., 2016; Tu et al., 2015).