Based on Landsat images, the spatial information of major gulfs along the coast of China in 2010, 2015, and 2020 were extracted to explore the morphological change characteristics. Some evaluation indexes, such as shoreline utilization degree, gulf area, gulf shape index, and gulf centroid, were used to analyze the gulfs' spatio-temporal change features in detail. The research showed that: (1) The shoreline length and structure of major gulfs changed significantly between 2010 and 2020, and the length and retention rate of the natural shorelines decreased. (2) The development and utilization degree of the gulf increased, with the increase rate gradually slowing down, and most of the gulf was moderately developed. (3) The gulf area continued to shrink, with a slow-down shrinking rate, and the gulf area in the Bohai Sea shrunk the most and the fastest. (4) The morphological change trend of the gulf is different from north to south. The north tends to be complicated, while the south to be simple. (5) After 2015, the gulf's plane center of gravity tended to be stable, the displacement distance decreased, and the displacement velocity slowed down. Human activities, such as sea reclamation, are the dominant factors leading to gulfs' morphological change. The national policies and measures for sea reclamation management and control in recent years have initially shown their effectiveness in affecting the gulf's morphology changes. The gulfs along the coast of China should be functionally positioned and divided, with refined classified management to optimize the layout of the "Ecological-Production-Living" space in the gulf areas.

The rapid erosion and deposition of tidal flat in alluvial island in estuaries due to the variations of land-sea sediments discharge has become the focus of urban development. Chongming Island, the largest alluvial island in China, has become an extremely valuable reserve land resource in Shanghai. However, the tidal resource in this island possibly presented new variation due to intensive human activities in drainage basins and estuaries. Accordingly, based on topographic data and measured bathymetric data around Chongming Island from 1984 to 2016, we illustrated the variation process of tidal flats in the study area through ArcGIS analysis and mathematical statistical analysis, and discussed the main factors influencing the geomorphic evolution of tidal flats. The results mainly include: (1) The process of erosion and accretion in each section of tidal flat around Chongming Island was complicated and varied. Totally, during the past three decades, the areas of the northern, southern and eastern beaches increased by 170 km², 8 km² and 51 km², respectively. (2) Variation of the northern tidal flat was affected by land reclamation, which led to the shrinkage of the north branch and promoted the continuous growth of the tidal flat. (3) The deposition of Xinqiao channel and its northward movement to the island directly caused the expansion of the southern tidal flat. The eastern tidal flat was dominated by frequent reclamation projects. Owing to the continuous outward movement of the embankment, the tidal flat expanded greatly in the past decades.

The bay is a unique strategic and ecological space in the coastal zone. Under the influence of global warming and intensified human activities, the shape and ecosystem of the bay have become more sensitive, fragile, and changeable. It is particularly necessary to clarify the temporal and spatial differentiation characteristics of wetland evolution in the bay areas under the influence of human activities and to find out the root cause of the wetland resource endowment. With the increase of satellite remote sensing data and the development of geographic analysis platforms (i.e., Google Earth Engine, GEE), rapid, low-cost, high-precision continuous monitoring of the evolution of the land surface becomes possible. The analysis of the temporal and spatial characteristics of the evolution of the bay wetland is of great significance for clarifying the resource and environmental base of the bay, understanding the comprehensive development potential, and promoting the sustainable development of the bay area. Taking the Sanmen Bay Wetland (SBW) in Zhejiang province as the study area, using Landsat TM/ETM+/OLI remote sensing image data from 1984 to 2019, based on the change characteristics of the spectral index time series, we extracted the information of the study area to examine its dynamic changes. The results show that the area of SBW has changed significantly since 1984, mainly found in the south of Ninghai county, the northeast of Sanmen county, and the southwest of Xiangshan county. In terms of the area, there was a fluctuating downward trend from 1984 to 2002, an accelerated downward trend from 2003 to 2009, and a steady development trend from 2010 to 2019. Human activities, such as reclamation, have caused significant changes in the shape of the bay, and the supply process of coastal zone management policy has become one of the important factors in the evolution of the bay wetland. The research can provide decision support for the construction of the bay area and the sustainable development of coastal areas in the future.

Coastal erosion is one of the major challenges in coastal zones. Coastal landscape, tourism and leisure functions have been seriously affected by coastal erosion in many tourist sand beaches. Artificial nourishment on regular tourist beaches is of great importance for maintaining beach grade and promoting sustainable tourist development. Based on analysis of coastal dynamics, sediment and beach conditions, as well as comparison of remote sensing images and beach profiles, erosion conditions and origins of erosion are examined on the east section of Sanya Bay, Hainan Island, China. Artificial beach nourishment that does not shift coast nature was proposed for restoration and preservation of the beach, concerning the scenic urban area. By analyzing beach landform, dynamics, native and borrowed sand conditions, we designed a beach nourishment project, with the goal of proving resistivity to erosion and increasing the material sediment supply of the beach. Comparison of satellite images and fixed beach profiles before and after beach nourishment shows that the beach was restored and broadened as designed. Profiles measured one and a half years after nourishment show that the nourished beach face and berm were relatively stable, without an obvious increase in the rate of sand loss. The east section of Sanya Bay is a relatively calm area sheltered by the Luhuitou Peninsula. Beach erosion is mostly induced by a decrease in foreign sand supply and enhancement of local dynamic forces due to sandbar reclamation, construction of hard structural revement and artificial islands. Weakening dynamic forces to reduce sand loss and/or adding an effective supply of foreign sediment by artificial measures are necessary ways to restore and protect the beach. However, hard structures like groins and breakwaters will have a negative effect on both the coastal landscape and tourists' safety. The proposed beach nourishment project does not modify the beach nature, which is a reliable choice for beach restoration in Sanya, a famous tropical tourist city in China. Practice of the beach nourishment project indicates that beach nourishment with suitable location, range and borrowed sand following the natural coastline, landform and hydro-dynamics is effective for restoration of beach erosion of the east section of Sanya Bay. However, beach nourishment is not efficacious forever. Sand loss is still inevitable after nourishment, because the hydrodynamics have not changed. Further sustained re-nourishment is necessary to maintain the dynamic stability of the beach. Meanwhile, no strong typhoon hit the area during the surveys after nourishment, further response of the beach to storm waves are to be concerned.

As important habitats, mangroves are a pool of benthic spawning genes and the biodefense line that intercepts continental pollutants. Ocean plastic pollution could lead to serious physical and toxicological effects on marine life and further threaten the stability and well-being of mangrove biodiversity. This study adopted methods of quantitative field observations and qualitative marine sampling. We, taking Qinglan Port, Hainan Island as the study area, collected marine waste, sediment and benthic organisms as the subjects of research. Visual identification, stereomicroscope observation and infrared spectrum analysis were used during the process to analyze features and sources of serious plastic waste. The findings show that the main plastic wastes include plastic bags, foams and fishing waste. Microplastics are a combination of flakes, fibers, lines, films, particles and spherical shapes, most of which are fabrics as a result of physical compression. The purpose of this study is to provide decisive suggestions to the government departments concerned for management and policy development to ensure maximum protection of mangrove forest habitats and their surrounding environments.

Global warming induced sea level rise is a hot topic in the field of land-sea interaction. Coastal erosion and flooding caused by sea level rise pose a great threat to the environment and economic development. We examined the spatial-temporal distribution characteristics and potential social and economic risks of sea level change in China's coastal areas from 1993 to 2018 based on the sea-level anomaly (SLA) data and the shared social and economic path scenario (SSP_S). The results showed that: (1) During the study period, the average annual sea level and extreme sea level in the study area showed a significant rising trend, with the rate of change reaching up to 3.47±0.50 mm/a and 4.74±1.39 mm/a, respectively. (2) The rising rate of the four major sea areas of China is listed is as follows: East China Sea > Yellow Sea > Bohai Sea > South China Sea. In terms of the provincial scale, Jiangsu, Fujian and Zhejiang have higher sea level growth rates, while Guangdong, Shanghai and Taiwan have lower sea level rise rates. (3) The results of MK test and Sen trend analysis showed that the average annual sea level had a significant increase trend in the whole study area. Specifically, 84.16% of the area had a moderately slow growth rate and 2.32% of the area was going fast. As for the extreme sea level, areas with a significant increase accounted for 76%, of which 59.65% had a slow growth and 2.31% had a fast growth. During the study period, there was no significant reduction in the area. (4) In terms of spatial volatility, the sea level change over the past decades had been at a relatively low volatility level. According to statistical results, the lower volatility area accounts for 61.31%, while the highest and higher volatility areas only account for 3.17%. (5) By 2100, under three shared social and economic development paths (SSP₁, SSP₂ and SSP₃), the potential economic losses in Chinese coastal areas will reach 10-21 trillion yuan, and the population affected by sea level rise is about 3.5-5.5 million. From the provincial perspective, Guangdong has the largest flooded area (accounting for 0.7% of the total land area of the province), and the highest economic and population risks. Therefore, mitigation and adaption to the risk of sea level rise is an important task for maintaining sustainable socio-economic development, resources utilization and environmental protection in China's coastal areas in the 21st century.

The IPCC special report on global warming of 1.5 °C and the IPCC special report on climate change and land both identify aquaculture as one of the key sectors that requires attention on global food security and the upgrading of adaptation policy. Research on the disaster-adaptive behavior and its influencing factors at the farmer level is of great value for enhancing the adaptive capacity to disasters, ensuring the livelihood of aquaculture farmers, and the sustainable development of islands, so as to revitalize fishing villages. However, very few studies have been conducted at the farmer level. Using survey data obtained from 202 aquaculture farmers from the Zhoushan and Dongtou Island regions and applying multivariate probit model, this study analyzes the disaster adaptation strategies of aquaculture farmers during the whole process of disaster management and the influencing factors. The results showed that: (1) Diverse multilevel adaptive strategies were adopted in study areas to deal with typhoon disaster. Up-front strategies, simple early strategies and future-benefits strategies were used significantly less than no-regret reaction and low-regret tactics by aquaculture farmers, making most farmers' adaptation strategies less effective. More than half of the farmers are willing to adopt the up-front, simple early and future-benefits strategies in the future if conditions facilitate usage of these strategies. (2) Each factor affected adaptation strategies of aquaculture farmers negatively and positively at the same time, and there was also significant complementary and substitutive relationship among the adaptive strategies selected by the aquaculture farmers. (3) Age, family labor, and the number of disasters occurring in the past 5 years were important factors influencing aquaculture farmers' adaptive behavior. Input, health status, disaster perception, income, education level, and social capital also had a significant impact on farmers' adaptive behavior. (4) Some influencing factors and their effects on the disaster adaptation behavior of aquaculture farmers in Zhoushan Islands and Dongtou Islands were different from those in other regions, which highlight the uniqueness of island regions. This study identifies the key influencing factors and weakness of adaptation behavior toward typhoon disaster, and the conclusions provide useful insight into the optimization and adjustment of the government and farmers' adaptation strategies.

To develop the marine economy and build a strong marine country, we need to care about, understand and manage the ocean from the perspective of national strategy. In order to systematically understand China's marine resource economy and strategy under the background of marine ecological civilization construction, nine well-known experts from marine-related fields were invited to discuss marine ecological civilization construction, marine land space planning, marine ecological pasture construction, and coastal ecological restoration. They conducted exchanges and interviews in frontier research fields such as marine strategic emerging industries, marine science and technology development, deep-sea mineral resources development, marine geopolitics, and China's participation in global ocean governance. According to their interviews: (1) The construction of marine ecological civilization is an important part of the construction of a powerful marine country. In the construction of marine ecological civilization, we should clarify the goal of building a beautiful ocean, master the methods of marine ecosystems, adhere to the major strategy of coordinating land and sea, and build an institutional system for marine ecological civilization. (2) National marine space planning should integrate existing sea-related plans, rationally develop, utilize and protect marine resources, innovate planning technologies and planning governance concepts, and strengthen marine space control indicators, marine space development capabilities, and local characteristic mechanisms for marine space governance, etc. (3) The construction of marine ranches should focus on the industrial chain and promote the construction of "all-for-one" marine ranches; strengthen the original drive, build an "all-for-all" marine ranch technology system; advocate integrated development and cultivate new "all-for-one" marine ranches. (4) Coastal ecological restoration based on "natural restoration" emphasizes the use of technologies to optimize the spatial layout and resource management of land-ocean staggered areas, fully consider the process and mechanism of natural restoration of coastal ecosystems, and improve the efficiency of ecological restoration. (5) The development of marine strategic emerging industries should grasp the general trend of the digital economy, focus on the development of intelligent manufacturing, accelerate the upgrading of the industrial structure, adhere to green and low-carbon development, and actively connect with regional strategies. (6) The key tasks for the future development of marine science and technology are to focus on the new strategic fields of deep sea and polar regions, improve the real-time fine observation and forecasting capabilities of key sea areas, focus on the intensive use of marine resources and energy, and strengthen the research and development of key core technologies of marine engineering equipment. (7) In the development of deep-sea mineral resources, it is necessary to strengthen international cooperation, carry out multidisciplinary investigation, long-term monitoring, enhance the research and development level of deep-sea development technology, evaluate the environmental impact of deep-sea mining, reduce the disturbance of the deep-sea development process to the marine environment, and realize deep-sea mining and deep-sea environmental protection coordinated development. (8) China should implement a spatially differentiated and targeted marine geostrategy to serve the unification of the motherland, the maintenance of marine rights and interests and the utilization of marine resources, and the safety of marine transportation and ecological environment, so as to ultimately serve the construction of a community with a shared future for the ocean. (9) We should implement the "going out" strategy of China's marine spatial planning technology, actively promote the strategy of building a "node network system" in China's overseas parks, and implement the talent training and training strategy for the needs of the Belt and Road Initiative, in order to provide necessary space fulcrum and technical support for global marine governance.

The integration of multiple marine spatial plans is a necessary measure to realize the modernization of national governance system and governance capacity. Marine function classification is the basic standard for the compilation and implementation of marine spatial planning, and the establishment of coordinated and integrated schemes in marine function classification systems is a necessary condition for the integration of multiple marine spatial planning, which is of great significance to the promotion and implementation of marine territorial spatial planning. Therefore, this paper selects the classification of functional zones in marine function zoning, one of the most important plans in the marine spatial planning system in China, as well as the sea area use classification proposed by the Ministry of Natural Resources recently as standards for national territorial spatial planning. On the basis of the clarification of the coordination connotation of marine function classification system and the sea area use compliance, environmental quality standards compliance, we establish a method to judge the coordination of marine functional classification system from three aspects: The conformity of marine use, the conformity of environmental quality standards and the impact of development and utilization, and construct the coordination matrix of the classification of marine functional zones and the sea area use classification. The results show that there are 22 pairs of sea area utilization combinations with coordination types of "compatible" or "conditionally compatible", which should be the focus of mixed utilization or stratified utilization of sea areas in future territorial spatial planning.

The evaluation of suitability of land and space development in coastal zone and optimization of functional space layout are the scientific basis for advancing the strategic goal of land-sea coordination. Taking Hainan Island as an example, this paper constructs an index system for the evaluation of the coastal zone "potential-limitation" based on the analysis of environmental benefits and losses, and comprehensively uses the multi-factor product and spatial overlapping methods, which is suitable for the development and construction of the land space in the coastal zone of Hainan Island. Then we carry out an integrated evaluation, and identify four types of coastal functional spaces: "port-industry-city" area, coastal tourism area, agriculture, forestry, animal husbandry and fishery area, and nature reserve based on the functional space discrimination conditions. The research shows that the areas that are suitable for land space development in the study area generally present a spatial distribution pattern of "more on the west coast and less on the east coast". The areas of suitable, basically suitable, basically unsuitable, and unsuitable for construction are 1785.32 km², 1724.57 km², 812.86 km², and 4051.67 km², respectively; suitable and unsuitable areas overlap and intersect, which brings tremendous pressure to the development of coastal land space. The areas of the four types of functional space in the coastal zone is 1813.39 km², 2138.26 km², 1831.62 km² and 2591.15 km², accounting for 21.65%, 25.53%, 21.87% and 30.94% of the coastal zone area respectively. The functional space of the coastal zone presents a "circle", "bipole" and "multipoint" spatial pattern. Based on the summarized three types of typical functional space conflicts, the functional space has been adjusted and optimized, and the agglomeration and connectivity of various functional spaces have been enhanced. However, the same functional space between sea and land is not connected, and the sea and land are economically connected. There are still many land-sea contradictions and conflicts in the development of land and space. The research results point out the development or protection mode of various suitability grade areas, expand the application conditions of suitability, and also enrich the theory on the suitability evaluation of land space development.

Offshore wind farms in deep-water area are characterized by great water depth, far from shore, and large scale. The reasonable planning of transmission spatial layout is directly related to investment cost and efficiency of sea use. And the calculation method of existing research only focused on two-dimensional (2D) plane, and the accuracy needs to be improved. In this paper, to draw a lesson from the idea of wind power gathering to islands and then sending out, a three-dimensional (3D) spatial layout optimization design model for offshore wind farms integration in deep-water area is established, and the wind farms in deep-water area of Eastern Guangdong is taken as an example in this study. The results show that: (1) The seafloor topography should be taken into account in deep-water wind farm integration. Although the sea bottom slope in the study area is very small, the total cable length of the optimized schemes is about 5% longer than that of the 2D plane. (2) The method of wind power gathering to islands and then sending out can effectively reduce the sea-area used and the total investment cost. And the largest reduction of sea-area used and total investment cost can reach 65%. (3) The lower the cable cost per unit capacity of different transmission modes, the closer the design scheme to the island-centered radiation pattern. The difference gradually decreases as the number of islands increases. The per unit capacity cost of the cable used for 220 kV alternating current (AC), 500 kV AC and ±320 kV direct current (DC) decreases in turn. When there is one island, the distance between the island and the collection center of the corresponding scheme is 38 km, 27 km, and 9 km, respectively. And when there are four islands, the distance is reduced to 19 km, 19 km, and 5 km, respectively.

As a major national strategy of China, land-sea coordination should not only realize the optimal allocation of land-sea elements at the national level, but also guide the spatial layout of land-sea industries at the regional level, so as to promote the coordinated development of the region. The current land-sea economy and land-space utilization research based on land-sea coordination is still in the exploratory stage, lacking systematic theoretical research and wide practical applications. Therefore, this paper discussed the research progress and existing problems of land-sea economic relations and land space utilization under the background of land-sea co-ordination from three aspects: Related concepts and theories of land-sea coordination, land-sea social and economic relations, coastal zone space utilization conflict and planning control. It is suggested that future research should focus more on multi-scale coupling and driving effect between land-sea resources and environment and land-sea social and economic development under the background of land-sea coordination, clarify the level of regional land-sea coordination and its evolution characteristics, influencing factors and response mechanism, pay attention to the diagnosis and control of coastal space utilization conflicts, and continuously promote the practice of coastal land-sea space planning based on land-sea coordination.

This paper examines the spatial differentiation characteristics and distribution dynamics of marine economic development in China's three major marine economic circles and identifies the influencing factors of its spatial disequilibrium and spatial spillover, which can provide decision-making reference for optimizing the spatial layout of marine economic development and promoting the coordinated and balanced development of regional marine economy during the 14th Five-Year Plan period (2021-2025). We use Gagum Gini coefficient and its decomposition method to investigate the degree, source and evolution trend of regional relative differences in marine economic development in the three marine economic circles (hereafter three circles). The kernel density estimation method is further used to describe the distribution dynamic evolution process of absolute difference. And we apply spatial econometric analysis to identify the key factors of marine economic development and spatial spillover effects. The results show that: (1) The development level of marine economy in the three circles has shown a steady upward trend, however, there is a significant differentiation among the three. The overall development level of marine economy shows a spatial pattern of eastern circle > northern circle > southern circle. (2) There is a significant spatial disequilibrium degree of the three circles, with a rising fluctuation trend and a deeping regional imbalance. The degree of regional difference between the southern and northern circles is the largest, and the degree of regional difference in the southern circle is the first among the three circles. The overall difference is mainly due to the cross overlapping effect between groups, and the contribution of intra-group difference is higher than that of inter-group difference. (3) The "polarization effect" of the marine economic development level of the three circles is significant, which presents different types of polarization trends. The three major circles as a whole and the northern circle have gradually strengthened from polarization to multipolar differentiation. The spatial agglomeration effect of the eastern circle is enhanced. The southern circle has always shown a multi-level differentiation trend. (4) There is significant spatial dependence in the development of marine economy in the three circles, and the overall performance is characterized by positive spatial correlation. Capital, labor force, innovation driven, marketization and opening-up have positive regional spillover effect, while environmental regulation has negative regional spillover effect. Capital, labor force, innovation-driven force and marketization have significant positive interregional spillover effects, while environmental regulation and opening-up have no significant interregional spillover effects.

With the increasing economic potential and strategic value of marine resources, the exploitation, utilization and protection of international marine resources, especially high seas reserves, have gradually become the focus of marine countries. From the perspective of geo-economy and the connotation of marine community with a shared future, this paper analyzes the basic principles of international marine resources exploitation and utilization. Based on the classification of international marine economic activities, the theoretical framework and technical methods of international marine resources strategic value evaluation are put forward. Firstly, according to the distribution characteristics of international marine resources and the spatial pattern of economic activities, the international maritime economic activities are divided into three types: Punctiform economy, linear economy and planar economy. In addition to the factors such as marine ecological environment, marine natural conditions and international rules, national strategies and geographical relations, the development of various economic activities is also restricted by specific technical bottlenecks, equipment support and transportation costs. Secondly, based on the value attribute of commodities, three properties of the strategic value of international marine resources are proposed, namely natural attribute, social attribute and geographical attribute. Then, a three-dimensional spatial conceptual model of the strategic value evaluation of international marine resources is constructed from three aspects: Natural value, demand degree and availability. The boundary and threshold of exploitation, utilization and protection of international marine resources are determined by using marine carrying capacity. Thirdly, with oil and gas exploitation, maritime navigation and fishing as the typical representatives, the paper builds a trinity index system, integrates production function, demand function and other measurement models, and preliminarily establishes a relatively complete set of international marine resources strategic value evaluation technology method. Finally, according to the strategic needs of China's participation in global ocean governance, the countermeasures of speeding up the exploitation, utilization and protection of international marine resources are put forward.

The evaluation of marine space development suitability, an important part of marine spatial planning, is of great significance to the implementation of a coordinated development strategy in the Guangdong-Hong Kong-Macao Greater Bay Area. We developed a methodology to evaluate marine space development suitability based on ecosystem service. Lingdingyang Bay is divided into key development zones, restricted development zones, prohibited development zones and reserved zones, in a descending order of marine space development suitability, which account for 30.63%, 22.71%, 23.37% and 23.29%, respectively. The relationship between development suitability and ecological protection importance of these four zones are high-low, high-high, low-low, and low-high, respectively. According to the resource endowment and sea compatibility conditions, we divide key development zones into single-function zones and compatible zones. Single-function zones, located in nearshore and sea areas around the islands, are accessible separately to port shipping, tourism and fishery activity, while compatible zones, located around Guishan Island, focus mainly on the synergy of supply and cultural services. Restricted development zones include ecological tourism zones and recreational fisheries zones, which are distributed in the coastal waters of Hong Kong and Macao, focusing on the tradeoff between the development of supply/cultural services and the protection of regulation/support services.

Accurate identification of high-quality development level of resource-based city economy is not only conducive to the transformation of urban economic structure, but also conducive to the sustainable utilization of resources. Based on speed, efficiency and production theory, this paper divides the high-quality economic development stages of resource-based cities. The panel smooth transformation (PSTR) model is used to identify the high-quality economic development level of 30 coal cities in China from 2003 to 2020, and further analyzes the transformation rules. The results show that: First, the high-quality economic development level of resource-based cities is highly correlated with the intensity of resource industry, and has obvious stage characteristics. Second, from 2003 to 2011, the number of coal cities at the high and medium level of high-quality economic decelopment increased from 12 to 19, and that at the low level decreased from 18 to 11. This indicates that most coal cities improved the high-quality economic development level. Third, the high-quality economic development of 11 coal cities has realized the single-stage transition, only Wuhai city has achieved the transition from low to high level, and the remaining 18 coal cities are in stagnation. Further, the driving mechanism analysis shows that industrial structure upgrading is an important factor to promote the transition of high-quality economic development stage in coal cities. It indicates that the improvement of high-quality economic development level of coal cities is a long-term process, which requires continuous promotion of economic transformation.

According to the comprehensive efficiency of multiple input factors in the evaluation of tourism resource efficiency, which cannot separate the output efficiency of a single input factor, in the perspective of tourism resource transformation efficiency, the resource transformation efficiency, its spatial differentiation characteristics and the interaction influence mechanism of the 81 typical red tourist attractions were evaluated by using the modified DEA model, spatial autocorrelation method and geographical detector model in Hunan province in 2020. The results showed that: (1) The transformation efficiency of red tourism resources in Hunan was 0.332, and it presented a spatial pattern of high in the east and low in the west. (2) Red tourism resources production efficiency and transformation efficiency of local space correlation from east to west gradually exhibited a decreasing trend. On this basis, the efficiency types of red tourism resources can be divided into five types, that is, the coordinated efficiency of production of red tourism resources, the comprehensive quality and efficiency improvement of red tourism industry, the transformation and upgrading of red tourism resources, the comprehensive production capacity improvement of red tourism resources, and the comprehensive efficiency cultivation of red tourism resources. (3) Three endogenous ability elements, namely, product innovation ability, human capital quality and tourism market scale, were the leading factors of red tourism resources in Hunan. Product innovation ability and science and technology information level, human capital quality and tourism market scale, human capital quality and economic development level were the internal and external factors leading to the spatial differentiation. The results enriched the theory of tourism efficiency research and can provide scientific reference for regulating the efficiency of red tourism resources to provide feasible development approaches and promoting the high-quality transformation and development of red tourism economy in Hunan province.

Resource-based cities are the cities that take the exploitation and processing of natural resources (minerals, forests, etc.) in the region as the leading industries (including prefecture-level cities, regions and other prefecture-level administrative regions, and county-level cities, counties and other county-level administrative units). They are important guarantees for the protection and utilization of energy resources in China and promote the sustainable development of the national economy. However, in the process of development, resource-based cities are facing problems such as resource depletion, environmental degradation, and lack of endogenous power of transformation. Therefore, promoting resource-based cities transformation and development is a key measure to accelerate the construction of ecological civilization and build a new development pattern in the new era. This study takes 19 resource-declining cities (prefecture-level cities) as the research object, and constructs an influencing factor index system of tourism transformation and development of resource-based cities, including four dimensions of ecological environment, resource environment, economic environment and cultural environment. On this basis, using the method of qualitative comparative analysis of fuzzy sets, this paper makes necessity analysis of single variable and multivariate path configuration analysis to explore the influencing factors and driving types of tourism transformation and development of resource-based cities. It is found that: (1) Environmental regulation is a single necessary condition for the transformation and development of tourism in resource-declining cities. Under the guidance of the government, effective environmental regulation can reduce the damage to the ecological environment caused by the economic growth of resource-declining cities, and then provide a good ecological environment for tourism development. (2) There are four driving types in the transformation and development of tourism in resource-declining cities: economic development driven, environment-culture driven, environment-energy-culture driven and environment-economy-culture driven models. On this basis, by comparing the core conditions of various types, we can further find that the environment and culture play a more important role in the process of tourism transformation. (3) There are four driving types leading to the transformation and development of non-tourism: environment-economy inhibition, environment-economy-culture inhibition, cultural endowment inhibition and economy-culture inhibition. It can be seen that economic development, cultural endowment and environment are the key to restricting the tourism development of resource-declining cities. From the perspective of configuration, this study combs the influencing factors and action mechanism in the process of tourism transformation in resource-declining cities, and further analyzes the driving types of "tourism transformation development" and "non-tourism transformation development". The research results not only enrich the relevant academic achievements of the transformation and development of resource-based cities, but also provide academic support and theoretical reference for their practical development.

The 'double evaluation' has become a scientific basis for constructing the spatial pattern of the national territory. The urban construction part of the current 'double evaluation' scheme is incomplete in terms of concepts, technical routes, specific methods and results application, making it difficult to guide planning practices. In response to the above issues, based on the national technical guidelines, this article takes Jiaxing city, Zhejiang province as an example, and optimizes it from three aspects: evaluation methods, index selection and evaluation application, with the following conclusions. (1) Distinguish strong restriction index and suitability index; replace the grading method with a multi-factor weighting method. (2) In the adaptability evaluation, add social and economic factors and distinguish general index system and local characteristic index system; in the carrying capacity evaluation, increase the constraint of water environment capacity to highlight the restrictiveness of water resources. (3) Integrate three applications to solve the guidance and connection problems. This article applies this optimized technical path, proving that it can effectively guide the 'double evaluation' in different types of regions to achieve intensive development, and provides a scientific and feasible technical framework that integrates multi-dimensional factors to achieve comprehensive urban 'double evaluation', which can be referenced by more urban areas in China.

The value realization of ecological products is a tough issue that needs to be solved urgently in territory spatial planning. There are many ways and means to realize the value of ecological products. Among them, the regional development unfairness, caused by the initial allocation of land development rights in different regions by territory spatial planning, should be partially corrected by ecological land compensation. This paper clarifies the institutional transformation of occupation and compensation balance from cultivated land to ecological land under the framework of territory spatial planning, tries to build a market-oriented trading mechanism of ecological products based on "Ecological Land Voucher", and takes Beijing-Tianjin-Hebei as an example. The results show that: (1) Territory spatial planning provides an institutional basis for the approval of "Ecological Land Vouchers". The transaction is to make up for the loss of land development right caused by territory spatial planning. (2) The difference between the amount of regional ecological land protection in the base year and the target year is defined as "Ecological Land Vouchers". It is proposed that the county-level local governments shall be the main body of the transaction, and the total amount of transactions shall be determined by the national annual plan management. The combination of the reserve price determined by the government and the market transaction pricing shall be adopted. (3) The ecological land is determined into four categories: forest land, grassland, wetland and water area. The area of "standard forest", after the changes of regional natural conditions, GDP and population density, is used to calculate the transaction volume of regional "Ecological Land Vouchers". (4) The case application results of the Beijing-Tianjin-Hebei Urban Agglomeration show that, from 2010 to 2018, the total demand for "Ecological land Voucher" in the Beijing-Tianjin-Hebei Region was 1420200 hm², mainly in Haidian, Xiqing, Jinnan, Wuqing, and Changli. The total supply of "Ecological land Voucher" is 747300 hm², mainly from Fangshan, Zhaoxian, Xinglong, Longhua, and Chengde. The research provides new ideas and relatively easy methods for the value realization of ecological products, and tries to help provide theoretical and technical support for the implementation of territory spatial planning and the protection and utilization of land resources for common prosperity.

The residential energy consumption indirect rebound effect has a wide impact but limited research. This paper estimates the indirect rebound effect of China's residential energy consumption in 2002, 2007, 2012, and 2017 using a combination of the redistribution model and the 20 sectors' environmental Input-Output table, with CO₂ emission being the measure. The results show that the indirect rebound effect of residential energy consumption is between 3.90% and 12.88%. The indirect rebound effect shows an inverse U-shape across the time dimension. Besides, the urban indirect rebound effect is consistently higher than the rural indirect rebound effect. This study conducts simulations focusing on three important factors that may change under the carbon peak and carbon neutrality goals to compare their impact on the indirect rebound effect. The analyses show that the indirect rebound effect increases the most when the residential unit carbon emission expenses increase. The indirect rebound effect decreases but not as much when the backward relating coefficients decrease and is affected the least by the simulated urbanization rate. In both general policy scenario and long-term low-carbon transition scenario, the indirect rebound effect in 2030 is greater than 13%, the general policy scenario in 2060 is as high as 46.55%, and the long-term low-carbon transition scenario is 11.77%. We discussed key policy recommendations for the carbon peak and carbon neutrality goals, including pushing forward policies to transform the energy structure as well as the whole economic system, and promote low-carbon residential consumption to offset the increasing trend of indirect rebound effect.

Based on the data of 11 provincial-level regions in the Yangtze River Economic Belt (YREB), this paper uses the undesired output SBM model to measure the carbon emission efficiency of planting industry, constructs the spatial correlation network through the modified gravitational model, applies the social network analysis method to analyze the spatial correlation network structure, and uses the QAP model to examine the driving factors of the spatial correlation network. The research shows that: (1) The carbon emission efficiency of planting industry in the YREB is improved rapidly, the overall efficiency value reaches a high level, but there is still some room for improvement, and the gap still exists between provincial-level regions. Moreover, the spatial effect of the carbon emission efficiency of planting industry in the YREB breaks the traditional spatial geographical proximity and presents complex spatial network characteristics. (2) During the study period, the correlation and structure stability of the spatial nnetwork of carbon emission efficiency of planting industry in the YREB showed an overall growing trend. During this period, the spatial correlation network evolved from the unipolar dominance of Shanghai to the multi-center collaborative development pattern of Jiangsu, Zhejiang, Guizhou and Shanghai. (3) Farmer per capita income, transportation level, spatial proximity relationship, science and technology level, and government agriculture attention level have an important influence on the spatial correlation network of carbon emission efficiency of planting industry in the YREB. It is suggested that when improving the carbon emission efficiency of the planting industry in the YREB, we should consider the spatial association network structure and its driving factors, and take measures to enhance the spatial correlation of the carbon emission efficiency of the planting industry.

To improve grain production efficiency in the main grain production areas is an important way to increase grain output and ensure food & ecology security. Besides, it is the focus of scholars, governmens and farmers. In this paper, the Huaihe Eco-Economic Belt (HHEEB), one of the typical main grain production areas in China, is taken as the study area. The index system for grain production input, including the direct input factors from farmers and the indirect public input factors from the government, is established. the grain production efficiency (q) of 28 DMU (cities) in the HHEEB in recent 20 years was calculated with the non-radial super-SBM, and the influencing factors of spatial differences in q were analyzed by using Geodetector. There are some findings as follows: (1) The mean value of q is around 1.0, which shows that the grain production efficiency can be greatly improved in the future. (2) There is a large gap in production efficiency between different DMU, but a convergence trend is observed in the past 20 years. The changes of production efficiency are diverse, which can be divided into 7 categories and 11 sub-categories. (3) The production efficiency presented the characteristics of agglomeration and contiguous distribution, and the overall spatial pattern of q remains relatively stable. (4) The spatial difference of production efficiency is affected by many factors. Among them, annual sunshine duration, population density and agricultural modernization are the basic influencing factors driving spatial differences, furthermore, the explanatory power of other factors is different and it changes in different years.

The construction of ecological belt along the Yellow River is an important action to implement the national Yellow River development strategy. This study takes the Yellow River section in Inner Mongolia as an example, which is facing seven complex ecological problems, including the degradation of forest land, grassland and wetland, desertification, salinization, soil erosion, and obstruction of biological habitat and migration processes. We propose the theoretical framework and implementation paths for the construction of the ecological belt along the Yellow River from three aspects as integrity, systematicity and uniqueness of multidimensional composite space. At the watershed level, the environmental quality assessment of forest land, grassland and wetland and the safety assessment results of desertification, soil erosion, salinization and biological processes were superimposed to construct a comprehensive ecological security pattern of the Yellow River Basin with low, medium and high safety levels. At the river level, it was found that the area of low security pattern of the main stream of the Yellow River had the largest proportion within 10 km outside the dam and 2 km on both sides of the first tributaries, so that we can identify the composition and spatial scope of the ecological belt along the Yellow River. Finally, conservation, restoration and remediation zones are defined according to landscape characteristics of different regions.