China’s service trade competitiveness is weak, and the service industry occupies a low position in the GVC (Global Value Chain); therefore, promoting the upgrade of the GVC of China’s service industry is worth studying. Under the new situation of the continuous integration of the digital economy and the real economy, the digital economy has injected new momentum into the mid-to-high end of the GVC of China’s service industry. Based on the panel data of the service industry sub-sectors, the mediating effect model is constructed, and the system GMM (Generalized Method of Moments) is used to empirically determine whether the digital economy can significantly improve the participation and position of China’s service industry in the GVC, and promote the upgrading of the GVC of China’s service industry. This conclusion still holds after replacing the independent variable measurement indicator, adding control variables, considering changes in industry trends, and using quantile regression and other robustness tests. The promotion effect of the digital economy on the upgrading of the GVC of China’s service industry shows heterogeneity in different service objects and service industries with different factor intensities, indicating that the digital economy will affect the internal structure of the upgrading of the GVC of China’s service industry. The results of the mediation test found that the service trade cost, multilateral resistance to service trade, service industry structure, financial development level, human capital and service export complexity are the mechanisms for the digital economy to enable the upgrading of the GVC of China’s service industry. This study improves the analysis of the impact factors of the GVC in the service industry, enriches the theory of the GVC, and improves the research content of digital economy theory. This study also provides a reference for other developing countries similar to China on how to promote the upgrading of the GVC of the service industry in the process of digital economy development.

The water environment quality is not high, the spatial and temporal distribution of water resources is uneven, and the water quality-induced water is in shortage in the world. Strengthening the construction of water ecological civilization is one of the important measures to solve these problems. We took China’s Jiangxi Province and its prefecture-level cities as the research object, the water ecological civilization level was measured from the two dimensions of time and space by principal component analysis, and based on the panel data of prefecture-level cities from 2011 to 2020, the panel data model was used to empirically analyze the impact factors of water ecological civilization. The results show that: (1) The level of water ecological civilization in Jiangxi Province shows a fluctuating upward trend, in which the level of water ecological civilization first increased, then decreased, and then increased from 2013 to 2020. (2) Water ecology is the key to affecting water ecological civilization, and cities with abundant natural endowments of water resources have higher scores for water ecological civilization. (3) There are significant differences in the level of water ecological civilization in different cities in Jiangxi Province; the level of water ecological civilization in southern Jiangxi and central Jiangxi is generally higher than that in northern Jiangxi; among the 11 prefecture level cities, Ji’an, Fuzhou, Jiujiang, Yichun, Ganzhou, and Shangrao have a high level of water ecological civilization. (4) Industrial structure, educational investment, and government governance level have significantly improved the level of water ecological civilization. Environmental pollution is not conducive to improving the level of water ecological civilization. There is an inverted U curve between the level of urbanization and the level of water ecological civilization. Accordingly, all prefecture-level cities in Jiangxi Province need to implement new development concepts and innovation-driven strategy, make up for shortcomings, and strengthen weak points according to their own natural endowments of water resources, such as optimizing the industrial structure, increasing investment in education, improving the level of government governance, and strengthening the connotation construction of urbanization, so as to promote the construction of water ecological civilization in Jiangxi Province. The research results also provide a reference for other countries similar to Jiangxi Province to solve the problem of water pollution, alleviate the pollution-induced water shortage, and improve the water ecological environment in the process of economic development.

To address the deterioration of the water ecological environment, China’s Ministry of Water Resources launched 105 pilot projects for the construction of water ecological civilized cities in two batches in 2013 and 2014. Based on panel data of 283 cities in China from 2008 to 2020, in this study, we investigate the impact of the pilot policy of water ecological civilization city construction on water pollution intensity using the difference-in-differences method. We found that water pollution intensity in the sample period exhibited a downward trend, decreasing most rapidly during the pilot construction period. Controlling for urbanization level, technological innovation, import and export trade, and foreign investment, our study results show that the pilot policy significantly reduced water pollution intensity. Mechanism analysis shows that the reduction effect was achieved through the channels of optimizing industrial structure, increasing sewage treatment, promoting water recycling, promoting technological progress, and speeding up water price reform. The results of this study also show that the policy effect in terms of reducing water pollution intensity is heterogenous across time, in addition to exhibiting regional heterogeneity owing to differences in levels of economic development, water resource endowment, and environmental regulation intensity. The research results also provide a reference for other countries similar to China to reduce water pollution intensity, address the deterioration of the water ecological environment, and improve the water ecological environment in the process of economic development.