Decomposition of industrial water use from 2003 to 2012 in Tianjin, China

•We decomposed driving forces of industrial water use changes in Tianjin, China.•The results of the refined Laspeyres and LMDI models agreed.•Output stimulated and technology inhibited water use; structural impacts varied.•Water use efficiency was not the primary goal of industrial restructuring.•Our findings can provide guidance for future water-saving cities in China.

This study analyzed the contributions of output, technological, and structural factors to industrial water use. Using Tianjin, a National Water-Saving City in China, as a case study, we adopted the refined Laspeyres and Logarithmic Mean Divisia Index models to decompose the driving forces of industrial water use changes. The decomposition results of both models show that output and technology have long-term, stable effects on industrial water use in Tianjin. Output stimulates water use, leading to an average annual growth of 7700 × 104 m3, while technology inhibits water use, with an average annual reduction of 7900 × 104 m3. However, the effects of structure on industrial water use are not stable. During the study period, the stimulation and inhibition of industrial water use alternated; however, stimulation was dominant after 2008, implying increased partiality of the industrial structure toward high water use. The results of the study contrasted the hypothesis that Tianjin's primary goal in restructuring local industries over the past decade has been the achievement of water use efficiency. Reduced water use may have resulted from Tianjin's development with targets other than water-savings.