مقاله سال ۲۰۱۶

China has been known to have scarce water resources, and this is particularly true for Tianjin (He et al., 2014). In mainland China, Tianjin has the lowest per capita water resources at 182 m3 /a, only 1/15 of the national average and significantly lower than the internationally recognized poverty line of 500 m3 /a. Up to 76% of surface water has been utilized in the region, which is much greater than the 40% global threshold. Severe water scarcity and shortages in Tianjin have hindered socioeconomic development and further strained the ecological environment (Shang et al., 2015). To ease its increasingly prominent water crisis, Tianjin has pioneered “the most stringent water management system” (Shang et al., 2016b) in China, which sets out water use efficiency targets and has achieved remarkable results. In 2013, water use per 10,000 yuan of gross domestic product (GDP) was reduced to 17.52 m3 (b1/6 of the national average), and water use per 10,000 yuan of industrial added value was reduced to 8.3 m3 , the greatest water use efficiency in the country. The Tianjin government believes that it has overcome the effects of water constraints on socioeconomic development by adjusting its industrial structure with water savings in mind. In light of this, we conducted an attribution analysis of industrial water use in Tianjin and believe that the findings will help alleviate water crises in northern regions and even achieve the synergetic and ef- ficient use of water and energy resources.

Existing literature on industrial water use has mainly focused on industrial water availability or assessed the negative ecological impacts of industrial water use. For example, Flörke et al. (2013) simulated changes in global industrial water use from 1950 to 2010 using the Water Global Assessment and Prognosis model and predicted a continued increase in industrial water use. However, to provide an incremental water supply, water conservancy projects, entailing storage, diversion, pumping, and transfer, generally require huge investments (Wang et al., 2015), which can be challenging for developing countries characterized by poverty. Countries experiencing droughts face the most serious water resource shortages (Wang et al., 2012). To protect the water security of these countries, control over the scale of water-intensive industries should be combined with efforts for the effective improvement of water conservation and water use efficiency (Alnouri et al., 2014; Hidemichi et al., 2012). To this end, Pham et al. (2016) conducted a water mass balance analysis of an industrial park in Vietnam and concluded that the current water management system did not have a suffi- cient basis in industrial water conservation. Thus, they recommended “reducing sewage discharge” and “improving water reuse” to address the high industrial water use. Futher, Agana et al. (2013) held that the effective integrated management of water use processes in urban industrial sectors could reduce sewage and help meet water use efficiency targets. Boix et al. (2012) also established a water supply network optimization model for industrial parks using the mixed-integer linear programming approach. By enabling the unified distribution of freshwater and recycled water, the model considerably increased the reuse of water resources. Lévová and Hauschild (2011) evaluated the water use life cycle of the biotech industry. Taking the carrying capacity of water resources as a constraint, this study proposed a suitable development scale for the biotech industry. With increasing industrial water use, wastewater can substantially increase (Kirkpatrick et al., 2011), and its discharge to rivers without treatment can cause serious water pollution (Englert et al., 2013). Given that in-depth sewage treatment requires considerable amounts of money and energy (Kajenthira et al., 2012), industrial sewage in developing countries is often directly discharged into rivers without treatment (Yi et al., 2011), which further exacerbates water shortages. The aforementioned studies considered water as a factor in industrial production and conducted quantitative analyses of the industrial development scale and industrial wastewater discharge using input–output or similar models. Accordingly, they offer policy recommendations for water reuse and sewage reduction to achieve sustainable water use and healthy industrial development.

The industrial structure of a city is by no means static; rather, it constantly changes (Bao and Fang, 2012). The industrial structure can include new industries, some that are new, traditional but renovated industries, and those targeted for elimination. Industrial development and structural adjustment are subject to multiple factors and drivers, and those processes can affect industrial water use (Geng et al., 2012). Researchers have gradually realized that identifying the key factors influencing industrial development and catering national macro-control policy to local conditions and circumstances are fundamental to healthy industrial development and water security (Yoo et al., 2007). In the late 20th century, the Kuznets curve was introduced for describing the relationship between economic growth and income inequity. According to this theory, in the early stages of economic development, income inequality increases with economic growth but is then expected to decrease towards equity once a certain level of average income is reached (Tate, 1986). The Kuznets curve has been widely used in many fields, including environmental protection and resource development (Foster, 2015; Muhammad et al., 2012; Saboori et al., 2012). In 1997, Merrett (1997) extended the theory to the field of water resources and found that, with continuous socioeconomic development, the demand for water grows, then exhibits zero growth and finally, declines. These three phases are also seen with industrial water demand in most developed countries. Many factors contribute to this decline, such as, optimized industrial structure, high water use efficiency, and a sound water system and economic instruments et al. Reynaud (2003) explored the impacts of different factors on incremental industrial water use by empirically analyzing factories. The results revealed that the water price, as well as government policies, significantly affected factories’ water use. Renzetti (2005) studied the relationship between industrial water use and economic development and suggested the use of economic instruments within a legal framework to promote industrial water conservation. However, these studies were limited to the qualitative description of laws governing water use and a rough exploration of influencing factors. Quantitative analyses of the contribution of different factors to incremental water use are sparse.