[Objective] Scientific research on the spatial distribution differences and mechanism of old-new growth driver conversion in the Yellow River Basin and Yangtze River Economic Belt is crucial for promoting coordinated regional development and achieving high-quality development in the two areas. [Methods] This study selected indicators from four aspects—growth power change, institutional mechanism transformation, structure upgrading, and change of the growth model—to develop a measurement indicator system for the level of old-new growth driver conversion. It compared and analyzed the spatial distribution differences of old-new growth driver conversion in the Yellow River Basin and the Yangtze River Economic Belt, and used geographic detectors to analyze the dominant influencing factors. On the basis of comparative analysis, the strategic focus of high-quality development in the two major areas was discussed. [Results] (1) The level of old-new growth driver conversion in the Yellow River Basin is lower than that in the Yangtze River Economic Belt, and there are significant internal spatial differences, showing a situation of high level in the upstream and downstream areas, and low level in the midstream areas. The eastern and western parts of the Shandong Peninsula urban agglomeration, as well as provincial capital cities such as Lanzhou, Xi’an, Taiyuan, and Zhengzhou, have higher levels of old-new growth driver conversion. The Yangtze River Economic Belt generally exhibits a characteristic of high in the east and low in the west. (2) The global Moran’ I shows no significant spatial correlation in the old-new growth driver conversion in the Yellow River Basin, while there is a significant positive spatial correlation in the Yangtze River Basin. Local Moran’s I analysis shows that the high-high clusters in the Yellow River Economic Belt mainly distribute in the eastern cities of the Shandong Peninsula urban agglomeration, while the low-low clusters mainly distribute in the Guanzhong Plain urban agglomeration. The Yangtze River Economic Belt is mainly characterized by a high-high clusters type, mainly distributs in the Yangtze River Delta urban agglomeration. (3) Urban scale, consumption capacity, and human capital are the core driving factors for the old-new growth driver conversion in the Yellow River Basin. The level of economic development, city scale, human capital, and opening up significantly promote the old-new growth driver conversion in the Yangtze River Economic Belt. At the urban agglomeration scale, the level of economic development, informatization, and opening up to the outside world have a relatively weak promoting effect on the old-new growth driver conversion in the Yellow River Basin, especially in the Guanzhong Plain, Jiziwan of the Yellow River, and Lanzhou-Xining urban agglomerations. The impacts of water resources and environmental regulations on the old-new growth driver conversion in the Yellow River Basin and the Yangtze River Economic Belt are gradually strengthening from east to west, especially in ecologically fragile areas such as the Jiziwan of the Yellow River, Lanzhou-Xining, central Yunnan, and central Guizhou urban agglomerations. In addition, the development of the Jiziwan of the Yellow River and the Lanzhou-Xining urban agglomerations in the Yellow River Basin is lagging behind, and an effective mechanism for old-new growth driver conversion has not yet been formed. [Conclusion] There is still much room for the improvement of old-new growth drive conversion in the Yellow River Basin and the Yangtze River Economic Belt and it is necessary to further develop new quality productivity, promote the transformation and upgrading of industrial structure, and continue to make efforts in promoting informatization construction and improving the level of opening up. In addition, it is also necessary to optimize the layout of major productivity forces and further promote the regional coordinated development.

[Objective] The purpose of this paper is to explore the impact path of technological innovation on carbon productivity, give full play to the carbon reduction and efficiency enhancement capabilities of technological innovation, and provide a reference for promoting regional high-quality development and the realization of the dual carbon goals. [Methods] Taking the Yellow River Basin and the Yangtze River Economic Belt as research regions, this study examined the influence path of technological innovation on carbon productivity and the mediation effect of digital finance by constructing a stochastic impacts by regression on population, affluence, and technology (STIRPAT) model and a mediation effect model respectively. [Results] The results show that: (1) Technological innovation of cities can improve regional carbon productivity levels, and the impact of technological innovation on carbon productivity exhibits regional heterogeneity. The impact of technological innovation on carbon productivity is stronger in the Yangtze River Economic Belt than in the Yellow River Basin. (2) Digital finance can partially mediate the impact of technological innovation on carbon productivity. Technological innovation can improve regional carbon productivity through digital finance. The mediation effect of digital finance is stronger in the Yangtze River Economic Belt than in the Yellow River Basin. (3) Improving the level of urbanization and economic development can promote the improvement of carbon productivity in the Yellow River Basin, and improving the level of urbanization and economic development and accelerating the upgrading of industrial structure can promote the improvement of carbon productivity in the Yangtze River Economic Belt. [Conclusion] This study suggests that local governments should enhance the technological innovation capabilities of cities, promote the deep integration of digital finance and traditional industries, strengthen regional industrial technology exchange and cooperation, promote the green transformation of industries in the Yellow River Basin and the Yangtze River Economic Belt, and ultimately achieve regional low-carbon and sustainable development.

[Objective] Accelerating the construction of a unified market is an important driving force for the implementation of the ecological protection and high-quality development strategy of the Yellow River Basin, and the impact and mechanism of market integration on the high-quality economic development of the Yellow River Basin can provide theoretical support and policy reference for the high-quality economic development of the Yellow River Basin. [Methods] The panel data of 69 prefecture-level cities flowing through the Yellow River Basin from 2011 to 2020 were selected as samples, and the impact of market integration on the high-quality development of regional economy and its mechanism and heterogeneity were explored by using the two-way fixed effect model, the intermediary model and the threshold model. [Results] (1) Market integration can significantly promote the high-quality economic development of the Yellow River Basin, and the high-quality economic development level of the Yellow River Basin can be increased by 0.579 units for every 1 unit increase in the degree of market integration. (2) Improving infrastructure, factor flow, and upgrading industrial structure are important mechanisms for market integration to promote high-quality economic development in the Yellow River Basin region. (3) There is a significant single threshold effect of economic agglomeration, and when the degree of economic agglomeration exceeds the threshold value of 0.020, the role of market integration in promoting the high-quality economic development of the Yellow River Basin is reduced. (4) There is regional heterogeneity in the promotion of market integration on the high-quality economic development of the Yellow River Basin, and the market integration of small and medium-sized cities has a stronger role in promoting the high-quality economic development, while the market integration of megacities inhibits its high-quality economic development. [Conclusion] It is necessary to accelerate the construction of market integration in the Yellow River Basin, improve the infrastructure in the basin, smooth the flow of factors, promote the upgrading of industrial structure, reasonably control the size of cities and the degree of economic agglomeration, and give full play to the high-quality dividend effect of market integration with the help of policies and local conditions.

[Objective] The digital economy helps to promote the green efficiency greatly, and then injects power into promoting the development of new quality productivity force. Exploring the mechanism of digital economy on green efficiency in resource-based cities is of great significance for resource-based cities to break path dependence, realize green transformation and high-quality development. [Methods] Taking 39 resource-based cities in the Yellow River Basin as the research object, and considering their geographic distribution, resource types, and development stages, this study measured the green efficiency value of these cities and its dynamic change in 2003-2020 using the data envelopment analysis-slacks-based measure (DEA-SBM) model. Heterogeneity analysis, mechanism analysis, and nonlinear analysis were used to explore the driving effect of the digital economy on green efficiency. [Results] (1) During the study period, the green efficiency value of resource-based cities in the Yellow River Basin gradually increased and tended to be stable. The downstream cities were better than the middle and upstream cities, the petroleum cities were better than the coal and metal production dominant cities, and the regenerative type cities were better than the mature, growing, and declining cities; (2) The digital economy significantly promoted green efficiency. Heterogeneity analysis showed that the effect of the digital economy on upstream cities, metal production dominant cities, and mature cities is more significant than that of middle and downstream cities and other types of cities; (3) The digital economy indirectly drove the improvement of green efficiency mainly through the intermediary effect of green technology progress rather than industrial structure, and urban agglomerations played a positive moderating role on the effect of the digital economy; (4) The nonlinear analysis showed that resource endowment did not have a threshold effect. The effect of the digital economy first increased and then decreased in its own double thresholds, but increased in the double thresholds of the year, indicating that the optimal level inflection point had not yet appeared. [Conclusion] The digital economy contributes to the green efficiency of resource-based cities, so we recommend to formulate incentive policies at the levels of the whole basin and urban agglomeration. On the basis of industrialization, cities can use the digital economy to reshape and upgrade the original industries in a timely and appropriate manner to jointly promote the green transformation and the development of the digital economy of resource-based cities in the Yellow River Basin, and further enhance the role of the digital economy in driving green efficiency through the implementation of differentiated measures.

[Objective] As a new type of economic form characterized by innovation, progress, and extension, digital economy is an important driving force to promote the high-quality development of the Yellow River Basin and create new advantages in regional competition. Exploring the evolution of the spatial pattern of digital economy enterprises in the Yellow River Basin and the influencing factors is of great significance for realizing the effect of digital economy reshaping the economic geographical pattern. [Methods] Based on the data of more than 130000 digital economy enterprises in the Yellow River Basin from 2002 to 2019, we used standard deviation ellipse, kernel density estimation, and the multi-scale geographically weighted regression model to explore the evolution of the spatial pattern of digital enterprises in the region. [Results] (1) The number of digital economy enterprises in the Yellow River Basin had increased significantly, showing the characteristics of downstream cities > midstream cities > upstream cities, with the overall spatial pattern of strong in the east and weak in the west and a trend of contraction, and the urban agglomerations showed significant differences in the development process. (2) The distribution of the digital industry manufacturing enterprises showed a trend of a single cluster of downstream cities and the orderly expansion of middle and upstream cities, while the digital technology application enterprises showed a trend of close connection between middle and downstream cities and multi-core clusters. (3) The location selection of digital industry manufacturing enterprises gives more consideration to location factors and has the characteristics of path dependence, while the location selection of digital technology application enterprises gives consideration to location and technology factors and has the characteristics of both path dependence and path creation. [Conclusion] Developing digital economy according to local conditions is an important means to achieve high-quality development of the Yellow River Basin, and we recommend to promote the digital economy industry to release its potential by improving its foundation, achieving precise layout, promoting innovation and optimizing the structure, and promoting innovation.

[Objective] The relationship between water ecosystem services and urbanization is related to regional sustainable development. The Yellow River Basin has pronounced water ecological problems, and clarifying the synergistic relationship between water ecosystem services and urbanization and their influencing factors will contribute to formulating development strategies. [Methods] This study evaluated the distribution pattern of water ecosystem services and urbanization from 2000 to 2020 by using the InVEST model and a comprehensive evaluation model, explored the trade-offs/synergistic relationship between the two using bivariate autocorrelation, correlation coefficients, and the division of variance method, and analyzed the ecological and social influencing factors on the Trade-offs/synergistic relationship based on the geographical and temporal weighted regression (GTWR) model. [Results] (1) The water ecosystem services of the Yellow River Basin urban agglomeration are dominated by food production and soil and water conservation services, and have been significantly enhanced; the level of urbanization has been increasing, and the differences between counties (districts) have been narrowing. (2) The spatial relationship between water ecosystem services and urbanization is dominated by the types of “low-low” and “high-low”, which show a trade-off relationship globally and a synergistic relationship locally in counties and districts, but the number of counties and districts with the trade-off relationship has gradually increased and is the main distribution of the northwestern part of the Yellow River Bend Metropolitan Area, the central part of the Guanzhong Plain urban agglomeration, and the eastern part of the Shandong Peninsula urban agglomeration. (3) Precipitation, ecological measures based on vegetation restoration, land-use intensity and location factors have mainly positive effects on the trade-offs/synergistic relationship, while the opposite is true for temperature, altitude, topography and level of economic development. Elevation and topography factors have the strongest influence on the trade-offs/synergistic relationship, followed by precipitation, and the rest of the factors have a weaker influence. [Conclusion] Therefore, to address the spatial mismatch between water ecosystem services and urbanization, ecological protection and development policies need to be formulated in zones and classified according to the synergistic relationship between the trade-offs between the two and the temporal differentiation of their driving factors.

[Objective] Clarifying the regional characteristics and variation trends of extreme precipitation events has great significance for ecological security and disaster mitigation under climate change. [Methods] Based on the observation data from 1961-2020, linear trend analysis, M-K test, Morlet wavelet analysis, and correlation analysis were used to analyze the spatiotemporal variation of extreme precipitation events and their sensitivity to climate change from previous period (1961-1990) and recent period (1991-2020) across the upper and middle Yellow River Basin. [Results] (1) Most extreme precipitation indices decreased first and then increased around the 1990s, except the continuously decreasing consecutive dry days (CDD). In the recent period, average daily rainfall intensity (SDII), rainfall on very wet days (R95), and rainstorm days (R50) significantly rose at 0.43 mm/(d·10a), 13.98 mm/10a, and 0.06 d/10a respectively (p < 0.05). (2) In the whole period, the southwestern part of the study region was relatively wet while the Yellow River bend area was the driest, and the extreme heavy precipitation presented more in the southeast and less in the west. In the recent period, the wetting trend in the upper Yellow River Basin gradually increased, and the frequency and intensity of extreme heavy precipitation in the middle Yellow River Basin increased significantly. (3) The average annual temperature in the upper and middle Yellow River Basin rose by about 1.5 ℃ with the acceleration of the warming rate during the past 60 years. The annual precipitation first decreased and then increased, and the upward trend in the recent period reached the extremely significant level (p < 0.01). The climate of the study region was transforming from warm-dry to warm-wet, especially in the upper part of the basin. Extreme precipitation was more sensitive to the annual precipitation amount than average temperature and had significant positive correlations, except for CDD. [Conclusion] The trends and magnitudes of variation of extreme precipitation events in the previous period and the recent period were much larger than that in the whole period. Since the 1990s, distinct warm-wet trend appeared in the upper reaches, while extreme heavy precipitation events increased significantly in the middle Yellow River Basin, requiring special attention to future floods.

[Objective] The GDP of Shandong Province ranks among the top in China, and the province has an important strategic position in the regional development of China. However, water shortage has been restricting the rapid socioeconomic development in Shandong Province. The research on water resources carrying capacity (WRCC), as an important indicator of rigid constraint of water resources, is crucial for regional sustainable development. [Methods] This study quantitatively evaluated the WRCC of 16 cities in Shandong Province during 2011-2020 and explored its distribution in different hydrological years, using the comprehensive weighting method and TOPSIS model. Then, the obstacle degree model was applied to diagnose the main obstacle factors of WRCC. [Results] This research found that: (1) Water resources carrying capacity was the highest (0.68) for the wet year (2020) but lowest (0.19) for the dry year (2014), which was overall weak (0.39) in Shandong Province. From 2011 to 2020, WRCC decreased first and then increased, which changed with the water resources endowment. (2) Spatially, WRCC showed an obvious regional difference. Annual average WRCC over the whole province was overall low, with the the highest in Jinan City (0.51) and the lowest in Weihai City (0.24). In the wet year, WRCC of most cities were relatively high, but the lowest was found in Yantai City (0.30) and WRCC was also low in northwest Shandong Province. In the normal year, WRCC overall decreased from the southwest to the northeast of the province. In the dry year, WRCC for all cities was low and thus showed insignificant difference. (3) Total amount of water resources, water production modulus, ecological water use ratio, surface water resources proportion, and wastewater discharge were the main obstacle factors of WRCC. Accordingly, water resources and ecological environment were the main obstacles to WRCC improvement. [Conclusion] Due to the water scarcity and low WRCC, at present and in the future, expanding water sources and reducing expenditure as well as improving quality and increasing efficiency will be crucial for the ecological priority protection and high-quality socioeconomic development in Shandong Province.

[Objective] Enhancing the coupling coordination of regional innovation-ecology-economy stands as a crucial avenue for China to attain high-quality development. This study assessed the innovation-ecology-economy coupling coordination level under the new developmental stages. It examined the coupling coordination path that emerges through the interaction and amalgamation of the constituent elements intrinsic to the innovation-ecology-economy system, approached from a combinational standpoint. Furthermore, the study aimed to clarify the principal course that will shape the forthcoming advancement of the coupling coordination of these three systems. [Methods] Using a sample of 30 Chinese provinces with data spanning from 2011 to 2020, this study integrated the new development concept to develop an evaluation framework for the composite innovation-ecology-economy system. From an intra-system perspective, the research employed a dynamic qualitative comparative analysis to identify the combination paths within the composite system that engender high coupling coordination levels, alongside their dynamic patterns of evolution. [Results] (1) In the study period, individual components of the system were insufficient for achieving coupling coordination development. But the interplay and alignment of components generated four combination paths of high-level coupling coordination, which can be categorized as “innovation and application of energy conservation and emission reduction for development” and “innovation and cultivation of environmental protection governance efficiency enhancement”, with the characteristics of “all roads lead to Rome”. (2) The role of applied scientific and technological innovation, and industrial structure optimization and upgrading in promoting regional coupled and coordinated development had weakened from the 12th Five-Year Plan to the 13th Five-Year Plan period. Instead, the core driving factors shifted to basic innovation, economic development quality catch-up, and sharing of development results. [Conclusion] Considerable potential for enhancement remains within China’s regional innovation-ecology-economy system for coupled and coordinated development. To foster further improvement, a concerted effort is needed to bolster interplay among the system’s constituent elements, addressing the deficiencies and vulnerabilities within sub-systems. Emphasis should be placed on bolstering scientific and technological research and development, advancing quality-driven catch-up initiatives, and cultivating common prosperity.

[Objective] At the core of geographic research, the theory of regional human-nature system is also an important theoretical basis for the study of sustainable development of the coastal zone, where the interaction between land and sea is intense. It is of great significance to clarify the characteristics of the spatial association network and the formation mechanism of coastal human-nature system resilience, which will help to grasp the cross-regional synergistic development of the resilience level and enrich the scientific research of the coastal zone. [Methods] Based on the panel data of 17 cities in the coastal zone of the Bohai Rim region from 2005 to 2019, this study used the variable fuzzy identification method to measure the level of coastal human-nature system resilience, and applied the modified gravitational model and the social network analysis method to study its spatial association network characteristics and formation mechanism. [Results] (1) There was a significant spatial association between coastal human-nature system resilience in the Bohai Rim region, but the network structure was relatively loose; (2) Tianjin, Qingdao, Yantai, and Dalian dominated the association network, and Cangzhou, Rizhao, and Dandong were in the periphery of the spatial association network; (3) Jinzhou, Yingkou, and Huludao belonged to the “net beneficiary” block, Weifang, Binzhou, and Dongying belonged to the “two-way spillover” block, Qingdao, Tangshan, and Tianjin belonged to the “net spillover” block, and Yantai and Dalian belonged to the “broker” block. (4) The QAP regression model revealed that geographic proximity, differences in economic development levels, differences in environmental quality, differences in human capital, and differences in informationization levels are the dominant factors in the formation mechanism of spatial association network of coastal human-nature system resilience. [Conclusion] To realize the development of a close-knit network of spatial linkages for coastal human-nature system resilience, it is necessary to promote the orderly flow of resource elements between regions and solve the problem of factor mismatch, so as to effectively enhance the complementarity of strengths and the mechanism for cooperation and exchange.

[Objective] Revealing the process and characteristics of land urbanization in coal resource-based counties, in order to provide a scientific basis for their spatial planning and intensive land use. [Methods] Taking Suixi County, a typical coal resource-based county, as a case study area, and based on remote sensing data and socioeconomic development data, landscape pattern index, expansion index, buffer zone analysis, and bivariate analysis, this study examined the spatiotemporal change characteristics of land urbanization in SuiXi County from 1950 to 2020, and then analyzed its driving factors. [Results] (1) Land urbanization in coal resource-based counties can be divided into three stages: town built due to coal resources, co-construction of a mining town, and integration of industry and city development, and the relationship between land urbanization and coal resources is “dependent-restricting-transcending”. (2) The period from 1950 to 1997 was the stage of “town built due to coal resources” and “co-construction of a mining town”, the urban construction land was distributed based on the location of the mines, and later extended on the basis of the original distribution; the growth of urban construction land changed from low-speed unbalanced to medium-speed unbalanced, and the county functional areas were mainly industrial, residential, and commercial. The period from 1998 to 2020 was the stage of “integration of industry and city development”, urban construction land mainly expanded in the periphery where new districts were built, showing a state of high-speed intensive development, and the county functional areas showed diversified development. (3) Land urbanization in coal resource-based counties is formed under the long-term action of many factors, and the dominant factors are different in different development stages. Among them, coal resources and location conditions are the basic driving forces, economic development and population growth are the direct driving forces, and development strategy and the policy system have the characteristics of short-term stability and sudden change. [Conclusion] At the stages of “town built due to coal resources” and “co-construction of mining town”, the development of land urbanization benefited from the development and utilization of coal resources. At the stage of “integration of industry and city development”, the development of land urbanization was significantly constrained by resource depletion and coal mining subsidence areas. Therefore, in order to achieve sustainable development in the urbanization of coal resource-based counties in the future, ecological restoration must be the primary task, and an intensive land use mechanism must be established.

[Objective] Improving the output efficiency of arable land is the core focus of ensuring national food security. The reform of “three rights separation” of agricultural land has significantly increased the enthusiasm of farmers for land management through empowerment, which inevitably has a significant impact on the output efficiency of arable land. The degree of influence and mechanisms involved deserve further investigation. [Methods] Based on the panel data from 146 prefecture-level cities in China from 2013 to 2021, this study first calculated the output efficiency of arable land using the data envelopment analysis (DEA)-Malmquist index method. It then employed a multi-period difference-in-differences test to examine the impact of the “three rights separation” of agricultural land on the output efficiency of arable land. Finally, by constructing a panel fixed effects model with interaction terms, it explored the mechanisms through which the “three rights separation” of agricultural land affects the output efficiency of arable land. [Results] The reform of the “three rights separation” of agricultural, significantly promoted the improvement of the output efficiency of arable land in China. This effect is also reinforced by legal clarity, and the results remains robust after conducting robustness tests such as placebo tests. Heterogeneity analysis revealed that the positive impact of the “three rights separation” of agricultural land on the output efficiency of arable land is more significant in the western region, northeastern region, groups with high per unit sown area planting industry output value, and groups with fiscal support for agriculture below the median level. Mechanism analysis found that the “three rights separation” of agricultural land mainly affects the output efficiency of arable land by weakening the impact of large-scale land management on the output efficiency of arable land and enhancing the impact of rural labor transfer on the output efficiency of arable land. [Conclusion] In the future, China should continue to deepen rural land system reform along the current path, further unleash the policy dividends of the “three rights separation” of agricultural land, and improve the efficiency of arable land resource utilization.

[Objective] Exploring the ecological impacts of the new round of grassland tenure confirmation can help to innovate and promote the grassland property rights institution for green governance, and provide a reference for the reform of grassland property rights in other countries and regions. [Methods] By applying field research data from pastoral areas in Inner Mongolia and the time-varying difference-in-differences (DID) model, this study explored the impacts of the new round of grassland tenure confirmation policy on grassland ecology and its mechanisms. [Results] (1) The new round of grassland tenure confirmation policy contributes to improved grassland ecology. Compared with those before tenure confirmation, the vegetation cover and plant height of grasslands after grassland tenure confirmation increased by 0.265 and 13.8 cm, respectively. This is the net impact of the positive property rights security effect and the negative scale fragmentation effect brought about by grassland tenure confirmation. (2) The security of property rights brought about by grassland tenure confirmation has changed herders’ attitude toward grassland use, improved their capacities, and promoted their ecological conservation behavior. (3) Heterogeneity analysis showed that the new round of grassland tenure confirmation is more effective for large herders to improve their grassland ecology compared to smaller herders. [Conclusion] This article suggests that the new round of grassland tenure confirmation could be carried out in pastoral areas with favorable conditions. By confirming grassland use rights of herding households, this policy is expected to improve grassland vegetation cover and height. In areas with small grassland area per household and complex topographic and geomorphic conditions, grassland tenure confirmation could be implemented according to local conditions, or considering to confirm the rights not to individual herding households but to small communities.

[Objective] In order to provide a reference for the formulation of sectoral water conservation strategies for the Haihe River Basin, it is urgent to systematically identify the leading driving factors for changes in water consumption by sector in the Haihe River Basin economic system and quantify their driving effects. [Methods] First, a set of input-occupancy-output tables with water resources of 49 sectors of the the Haihe River Basin at constant price in 2007, 2012 and 2017 were compiled. Based on these tables, a structural decomposition analysis model of changes in sectoral water consumption with 11 driving factors was constructed. [Results] (1) From 2007 to 2017, the improvement of economic development level was the main reason for the increase of total water consumption, but its driving effect weakened with time. The decrease of industrial production water intensity and the change of final demand structure of sectoral products were the main reasons for the decrease of total water consumption during 2007-2012 and 2012-2017, respectively. (2) Irrigation water intensity and the final demand structure of sector products were the most important factors for the decrease in water consumption of agriculture during 2007-2012 and 2012-2017, respectively. (3) The driving effect of production water intensity on the change of water consumption in the industrial sectors weakened over time. The growth of final demand for products of industrial sectors continued to drive the increase of water consumption in the industrial sectors. (4) The change of the production technology level and the total final demand structure had a stronger driving effect on the increase of water consumption in the service sectors than in the agricultural sector and the industrial sectors. [Conclusion] From 2007 to 2017, the reduction of total water consumption in the Haihe River Basin showed a trend of change from being mainly driven by water conservation technology to being mostly driven by final demand structure. From the perspective of inter-industrial comparison, the main driving factors of water consumption change in different industries had obvious sectoral characteristics. We recommend to formulate water conservation measures for each industry based on its main drivers of water consumption change.

[Objective] The subsurface freshwater lens of coral islands is an important resource necessary to maintain the production and living of islanders and ecological conservation. Accurately identifying the morphology of subsurface freshwater lenses on coral islands and revealing the mechanism of subsurface freshwater recharge are important bases for the assessment of groundwater resources on reefs, and are crucial for improving the management of groundwater resources on coral islands. [Methods] Taking Dong Island as the research object, this study combined with hydrogeological survey and high-density resistivity method to identify the distribution of freshwater lenses near sand barriers, and describe the brackish water interface. [Results] The results show that the freshwater lenses on the northwestern and southern parts of the island were relatively developed, and the thickness of the freshwater lenses below the sand dikes was 3-7 m. In the southeast of the island, there were also freshwater lenses developed in the higher terrain, but the thickness was thinner than in the sand barriers, and there was even no fresh groundwater in some local areas. [Conclusion] The development of freshwater lenses in Dong Island is associated with the distribution of topography and vegetation, and the water consumption by evapotranspiration of vegetation is the main factor that causes the thinner freshwater lenses in the low-lying land on the island.

[Objective] Indium resources are an important supporting raw material for the development of China’s strategic emerging industries, and the study of the current status and dynamic evolution of the value flow of indium resources across the whole industry chain is of great strategic significance for the security of China’s indium resources and the sustainable development of its economy. [Methods] Based on the material flow framework of China’s indium resources in 2019, this paper utilizes the value chain analysis method and maps the value flow of China’s indium resources corresponding to the material flow process of indium resources according to the factor price theory, in order to evaluate and analyze the changes of value increase and decrease in the whole industry chain of China’s indium resources. [Results] (1) The total value of China’s indium resources industry chain shows an inverted U-shaped trend of increasing and then decreasing; (2) The stages with the highest value appreciation in the indium value chain are smelting and refining, with value increases of 922% and 1002% respectively. This is attributed to the substantial enhancement of indium resource grade due to the inputs of technology, labor, and energy, and that indium is a by-product metal with its associated zinc metal having relatively low value; (3) Although China is the world’s largest country in terms of indium resources, the indium resource industry chain still relies on imports to sustain its development; (4) Recycling of indium resources can have significant economic value. [Conclusion] Therefore, optimizing the indium resource industry chain, upgrading the production process and technology of high-end indium-containing products, and strengthening the recycling of indium-containing waste products are important ways to increase the value of indium resources in China.