China's water resources is characterized by heterogeneously spatial distribution, low use efficiency, and severe supply-demand conflict. This paper measures China's provincial water use efficiencies, and studies their temporal-spatial evolution and driving mechanism, providing reference for China to improve water use efficiencies, to boost ecological civilization construction and sustainable development. Super-efficiency SBM model is used to estimate China's 30 provinces' (cities) water use efficiencies from 2004 to 2019, and non-parameter kernel density is applied to illustrate their temporal-spatial evolution from two levels, nationwide and eastern, middle and western regions. Spatial visualization, spatial autocorrelation and cold-hot point are employed to depict their spatial pattern evolution from spatial differentiation and spatial correlation, and geographic detector is used to explore the temporal-spatial heterogeneity of drives and interactive mechanism among drives. The water use efficiencies show a falling trend in a fluctuated manner in the whole China and in eastern, central and western, with decreasing province counts of higher efficiencies, and increasing of lower, suggesting provincial efficiency variance has experienced an enlarging-diminishing evolution. China's water use efficiency shows a distributing pattern of eastern-middle-western, downwards, spatially, existing an outstanding positive spatial auto-correlation with a high-high and low-low clustering feature, and showing a “U-shaped” evolution of strong-weak-strong. From 2004 to 2019, China's water use efficiency displays an intensifying spatial differentiation with polarization of “eastern hot-western cold”, hot ranges shrinking then dispersing, and cold ranges shrinking then stabilizing. All drives largely vary with periods and regions. Q values of drives from 2004 to 2019 has been outstandingly increased with a diminishing variance. The major drives are becoming diversified, but economic level and urbanization level are always the key drives. After any drive is interacting with the other, the both will be increased, or in a non-linear increased, indicating that the two drives can jointly will intensify the spatial differentiation of water use efficiency.

This paper measures the decomposition effects of industrial water use factors in the Yangtze River Delta region, analyzes the decoupling status and relation between industrial water use and economic development, and offers references for making industrial water use policies, mitigating water consumption, and boosting a high quality green development in the Yangtze River Delta region. Based on temporal data in the Yangtze River Delta region from 2001—2018, this paper uses LMDI model to decompose the factors of industrial water use changes, and applies Tapio elasticity index to study the decoupling relation between industrial water use and economic development. A decoupling effort model is built with removal of economic output effect, which is used to analyze the decoupling effort extent of the other factors of industrial water use reduction. The factors of industrial water use could be decomposed to four major effects. Water-saving technology has an accumulative effect of -73.101 billion m³, which mainly inhibits the increase of industrial water use. Industrial structure and population have an accumulative effect of 64.4 billion m³ and 71.08 billion m³, both increasing industrial water use. The decoupling state of the Yangtze River Delta region shifts from weak decoupling to strong decoupling on the whole, varying with provinces/cities. Decoupling effort index of water-saving technical effect, the biggest contributor to decoupling, is always above 0, while that of industrial structure effect and population effect is normally below 0, small and varying with provinces/cites. This paper concludes water-saving technical advance is the chief factor to restrain the increase of industrial water use; industrial structural adjustment is the minor factor to reduce industrial water use, while the economic output and population effects are the major factors that lead to the increase of industrial water. Therefore, in order to achieve the balanced development between economic and environment, the Yangtze River Delta region should improve water-saving technologies, strengthen policy guidance, promote industrial upgrading and accelerate economic transformation.

Geological exploration as the upper end stream of economy is led in inputs by the downstream demands. Industrial developing stages determine mineral product use intensity, which determines the input intensity of geological exploration. China's industrial structure evolution indicates that China has entered into the middle-post of industrialized stage, mineral product use intensity and geological inputs will be falling into declining period in a long term. Global competitiveness or rapid industrialization in nations on “the belt and road” is the approach to re-energize geological exploration, but can not be foreseen in the near future. Geological talents will be structurally short and generally excessive under China's declining geological exploration sector for a long term.