Grey Water Footprint Assessment from the Perspective of Water Pollution Sources: A Case Study of China

Abstract

With the acceleration of industrialization and urbanization, the water crisis is becoming more severe and may threaten the future of sustainable development. Assessing grey water footprint (GWF) is a useful step in the prevention and control of water pollution. Conventional studies have only considered agricultural pollutants in their calculations of GWF, ignoring the roles of industrial and household wastewater. Therefore, this study calculates GWFs for the agricultural, industrial, and household sectors in 31 provinces in China from 1998 to 2012. It further analyzes spatial and temporal variations in China’s GWF. The results show that total GWF (TGWF) was relatively high from 1998 to 2002, then increased steadily and peaked in 2006, and dramatically decreased after 2006. Overall, TGWF slightly decreased over the study period. 31 Provinces were divided into five grades of TGWF: very high, high, medium, low, and very low. The provinces with high or very high TGWF, such as Hebei, Shandong, Henan, Jiangsu, Hubei, Hunan, Sichuan, Guangdong, and Guangxi, were primarily located in southeastern and southwestern China. Therefore, efforts to reduce GWF should focus on these regions. Our comparative study also provides a means of understanding how key contributors to GWF vary across the five regions. It offers a basis for the short-term and long-term development policies aimed at decreasing GWF in specific locations.