Development of a conceptual regional industrial water use efficiency model driven by economic development level

Study region: The study area comprises 336 administrative units located in mainland China. Study focus: The research aims at better understanding the relationship between regional industrial water use efficiency (IWUE) and the economic development level (EDL) that drives its annual variation, and to create a conceptual model to simulate these variations. A method is proposed for estimating regional IWUE for the following year via parameter calibration and extension in mainland China. New hydrological insights for the region: A conceptual model is developed to simulate annual regional IWUE(water use per 10,000 yuan of industrial added value) variation driven by EDL (GDP per capita). The model has an even number of hyperbola lines indicating log-transformed IWUE state fluctuations relative to EDL index. The model is derived based on three key findings. The categorical hyperbolic correlation between the EDL and IWUE allows similar model structure in different rank match levels. Second, multi-year data sets can calibrate the shape parameter because the hyperbola's shape remains constant over the years. Furthermore, regional IWUE can be predicted by the hyperbola's linear location with year. The model offers a new quantitative analysis method for setting regional IWUE control red lines in China. It could also serve as a foundation for studying the relationship between IWUE and other socio-economic characteristics in different nations and developing regional and possibly worldwide IWUE model construction and parameterization.