1. Introduction

Since the 18th Party Congress, China's urban-rural integration and development has made great progress, with the comprehensive liberalization of the policy on the migration of residents' household registration, the equalization of basic public services in urban and rural areas has been promoted in-depth, the level of urban-rural infrastructure integration has been continuously improved [1], and the quality of life of the rural residents' level has been greatly enhanced. The Strategic Plan for the Revitalization of the Rural Areas (2018-2022), released by the State Council in 2018, clearly puts forward the goal of promoting the integrated development of urban and rural areas and constructing a modern rural economy. The goal of modernizing rural economies. In the same year, the National New Township Plan (2014-2020) also emphasized the need to adhere to a people-centered, coordinated approach to sustainable economic, social, and environmental development in the urbanization process.

Although the progress of China's urbanization with economic development is constant and rapid, the economic and social gap between urban and rural areas is still significant; the problem of unbalanced and insufficient development between urban and rural areas still exists, mainly in the urban and rural residents income and the income gap between residents, the imbalance of basic public facilities [2], uneven public services and other issues. This urban-rural dichotomy has, to a large extent, constrained the overall development of society, and there is thus an urgent need to realize urban-rural integration through innovations in policy and development mechanisms.

The rapid urbanization brought about by China's rapid economic development has also brought about the unbalanced allocation of resources such as land, capital, labor, etc. The integration of urban and rural industries in the county is not close enough [3], and the mechanism of the two-way flow of urban and rural elements is not perfect [4], and the development of agriculture for the industry as a back output and direct natural resource reserves has led to the loss of rural resources, ecological environment damage, and other problems. The consumption of ecological resources in the process of urbanization also puts pressure on the ecological environment in the countryside. The reduction of agricultural arable land and the growing problem of agricultural pollution pose a threat to rural ecology and sustainable development. To solve this problem, the combination of new urbanization and rural revitalization alleviates the imbalance between urban and rural resource allocation and promotes green development through rational resource allocation and environmental protection strategies.

The purpose of this paper is to systematically sort out the research results on the combination mechanism of new urbanization and rural revitalization at home and abroad, analyze the shortcomings of the current research, and summarize the key influencing factors and the evaluation index system to promote the development of future research in related fields.

2. Literature Review

2.1. Core Concepts and Theoretical Foundations of New Urbanization and Rural Revitalization

2.1.1. Connotation of new urbanization and rural revitalization

The new urbanization strategy emphasizes a green, intensive, intelligent, and low-carbon urbanization process that focuses on human beings, ecological sustainability, and sustainable use of resources, taking the county as an important carrier, the county economy as the focus of development, and paying attention to the protection of citizenship [5]. New urbanization is different from the traditional crude development mode, with more emphasis on the enhancement of urban carrying capacity, optimization of resource distribution, improvement of residents' living standards, and reduction of the phenomenon of "development before governance" [6]; exploration of innovation and coordination-driven development paths, and narrowing the gap between urban and rural areas through policy and industrial orientation.

Rural revitalization is a systematic strategy put forward by China to address some of the deficiencies in the development of rural areas that still existed in the previous process of industry feeding agriculture in the countryside, and at the same time, to address the development of economic, social and ecological aspects, to comprehensively realize a strong agricultural economy, the beauty of rural ecology and humanities, and the prosperity of peasants, and with the focus on improving the level of rural development, rural construction, and rural governance. Emphasis is placed on the comprehensive revitalization of rural industries, human resources, culture, ecology, and organizations [7] to improve the level of rural development, enhance the well-being of rural residents, and provide support for the realization of modernization of rural human resources, infrastructure, and social governance, as well as common prosperity.

2.1.2. Theoretical Basis for Coordinated and Integrated urban-rural Development

Combined with Marx and Engels’s theory of urban-rural integration, a profound grasp of the basic contradictions of the society of capitalist countries based on the phenomenon of urban-rural dichotomy due to the interaction of productive forces and relations of production and laddering of the development of the results, the emergence of “all the developed, the basis of the division of labor mediated by the exchange of commodities, is the separation of urban and rural”, with the gradual development of productive forces, this separation will gradually die out [8]. With the gradual development of the productive forces of this urban-rural separation will gradually disappear. Along with the high development of productive forces, the development trend of urban-rural relations will be from the state of separation and antagonism to integration [9]. This is material, determined by the contradictory laws of movement of productive forces and production relations, and cannot be shifted by human will. Only by realizing the integration of urban and rural areas can we change the limitations imposed by the social division of labor between urban and rural areas on people engaging in labor activities, and thus promote the free and comprehensive development of people. This is of great significance for a deep understanding of the changes in China's urban-rural relations since the founding of the People's Republic of China and the logic of its practice, as well as for grasping the trend of urban-rural integration and development.

2.2. Comparison of urban-rural integration between China and other countries

2.2.1. Japan's urban-rural development strategy of "promoting rural areas through urbanization"

As a leader in urban and rural development, Japan's rural revitalization strategy adopts a unique model of multiple leadership. In the context of the post-growth era, Japan has taken a composite development path that ranges from central policy support to grassroots self-formation, and this "top-down" combined with "bottom-up" model of rural revitalization strategy is in line with Japan's previous urban-rural economic model, and it also enables the economy to recover rapidly after the Shinkansen epidemic. This "top-down" combined with the "bottom-up" model of rural revitalization in Japan is consistent with Japan's previous urban-rural economic model and has led to rapid economic recovery after the Shinkansen epidemic. Unlike China's top-down policy-driven rural revitalization model, Japan has injected more local autonomy and participation into rural revitalization through a combination of central government policy guidance and local autonomy [10].

The revitalization of the Japanese countryside has been supported not only by policy but also by a strong grass-roots search for autonomy. Many rural communities have developed economic models for food through the renovation of abandoned houses and the promotion of handicrafts and small-scale agriculture. In Onomichi City, Hiroshima Prefecture, abandoned houses are transformed into B&Bs and handicraft workshops through the Empty House Regeneration Project, which reuses local unused or abandoned resources, provides a unique experience for migrants and tourists, pulls in local consumer attraction, and gradually builds up a community network to reduce dependence on external investment [11]. Self-innovation projects with local characteristics not only increase the diversity of local economic development models, but also enhance the community's aggregation power and economic reengineering capacity. According to other studies, the concept of "relational population" [12] has been proposed to further diversify urban-rural interactions, i.e., to bring more social, cultural, and economic capital to the countryside through temporary residents who do not regularly reside in the countryside or participate in countryside activities, thus creating a non-traditional mobile population structure, which is a much different approach to China's rural revitalization policy, which is dominated by permanent residents.

Given Japan's limited agricultural resources, some Japanese villages have chosen to gradually abandon their heavy reliance on a single foodstuff in the course of their development and have shifted to a diversified food production and consumption structure. Take the Seto Inland Sea's art island model as an example, although the art festival activities have successfully attracted a large number of tourists, it also exposes the drawbacks of resource scarcity that makes the rural economy overly dependent on agriculture and thus brings further development risks - excessive commercialization leads to a decline in the original quality of life of some community residents, in other words, with the original model of rural agricultural development In other words, it is difficult to adapt to the growing exogenous demands of the rural agricultural development model. The consequent improvement is that some rural communities are gradually exploring economic models led by small-scale agriculture, organic food, and cultural and creative industries to achieve endogenous development and sustainable a economy [13]. This model of combining the development of higher-level policies with lower-level economic responses not only meets the need for rural revitalization in the post-growth era but also demonstrates Japan's flexible decision-making in response to issues such as aging rural populations and resource scarcity.

Japan's rural revitalization has developed a relatively unique path of revitalization in the post-growth era through diversified policy support, autonomous local economic development models and multi-level urban-rural population interaction, combined with diverse and more realistic evaluation indicators. This path provides a reference for China's rural revitalization in certain procedures, especially in terms of enhancing community participation, developing a diversified economic structure and actively coping with the demographic structure, which provides important academic references and practical experiences for rural development in the post-industrialization era.

2.2.2. The development situation in the United States, where urban and rural areas are mutually reinforcing and real conflicts exist side by side

In a number of earlier studies, it was recognized that the United States was at the forefront of urban-rural integration in the world [11-12]; however, while the urban-rural divide has become a persistent problem as the economy has continued to grow, recent trends suggest that integration between these two regions is increasing. While urban-rural integration is evident in areas such as infrastructure development, migration, and rural revitalization policies, large structural differences continue to exacerbate the separation of these regions.

Rural-urban integration in the United States is reflected in both physical infrastructure and human mobility. Transportation networks, particularly road infrastructure, play a key role in connecting rural and urban areas.Burghardt et al. show how the U.S. road network has evolved over time, demonstrating that rural communities are increasingly connected to urban economic centers through improved infrastructure [14]. This integration facilitates the movement of not only goods and services but also people, thereby reducing physical and economic disparities between rural and urban areas.

Beyond infrastructure, migration patterns reflect the increasing interdependence of rural and urban spaces. Increasingly, urban dwellers are moving to rural areas in search of affordable housing, lower costs of living and a better quality of life. This reverse migration is largely due to the rising cost of living in metropolitan areas and the growing acceptance of teleworking. The flexibility afforded by teleworking has made rural areas more accessible and attractive to urban dwellers, thus contributing to some extent to urban-rural integration.

A number of policy initiatives aimed at promoting rural development have also sought to narrow the urban-rural gap. The United States Government has invested in projects that encourage the economic revitalization of rural communities through infrastructure development, education and health care, and Warner highlights the importance of local governments in providing critical physical and social infrastructure, which is essential to promoting rural economic growth and inclusiveness [15].

The approach to urban-rural integration in the United States has historically been decentralized and driven primarily by local and state governments, with some support from the federal Government. Efforts to narrow the urban-rural divide, such as infrastructure development and migration patterns, have been largely market-driven, with private and community-led initiatives playing a key role.

2.3. Selection and application of evaluation systems for urban-rural integration

2.3.1. Main evaluation mechanisms

Regarding the selection and application of evaluation systems for urban-rural integration, academics have proposed a variety of models and methods to quantify and comprehensively assess the progress and coordination of urban-rural integration. Commonly used models include the coupled coordination degree model [16, 17], the entropy method, the hierarchical analysis method (AHP) [18], and TOPSIS [19], etc., and the scales of the study are based on the country, region, urban agglomeration, and province and city. The hotspot areas of research involve the Yangtze River Delta, the Capital Ring Region, the Huaihai Economic Zone, and developed provinces such as Jiangsu and Zhejiang. Endpoint models have their own advantages and limitations in the evaluation of urban-rural integration and thus need to be selected according to the specific research objectives and data characteristics.

2.3.2. System selection for evaluation and case study of urban-rural integration development in Jiangsu Province

2.3.2.1. Coupled Coordination Degree Models

The coupling coordination degree model is a model that can calculate the social connection and good effect between economic, ecological and other elements in the process of urban-rural integration. Its core meets the "degree of coupling" of urban and rural elements, that is, the degree of coupling between the elements of the model is especially suitable for complex systematic analysis, which can provide a comprehensive assessment of different dimensions in the process of urban development, and at the same time, some scholars have used the coupling model to analyze the degree of urban-rural association in the counties and townships under the digital economy, which is suitable for the city. In contrast, although the entropy value method and the hierarchical analysis method (AHP) are also suitable for the evaluation of urban-rural integration, they are more dependent on the weight distribution, and it is easy to take the optimal value of each index due to the greatness of the impact on the stability of the assessment results, whereas the coupled correlation model can reduce the influence of people on the assessment results through the intrinsic relationship between the data, thus providing more detailed assessment results.

2.3.2.2. Three major dimensions of the evaluation of urban-rural integration development in Jiangsu Province

In the construction of the specific evaluation system, the evaluation framework based on the coupled coordination degree model covers the design of comprehensive indicators in the three dimensions of economy, society and ecology to determine the level of coordination of urban-rural integration in Jiangsu Province. Jiangsu Province has the basic conditions of better integration in terms of urban and rural areas [20], and the economic, social and ecological development is relatively balanced, so the evaluation system design can be centered on the following three dimensions:

Economic dimension: This dimension includes indicators such as the proportion of urban population, the income gap between urban and rural residents, the GDP of rural areas, the degree of marketization of agricultural products, and the development of digital information technology to reach the deep integration of urban-rural economic interaction in Jiangsu Province. Jiangsu in the rural economy through the modernization of agriculture, rural infrastructure development and the extension of the industrial chain and the collection of small and medium-sized enterprises and other economic dimensions of the evaluation can help identify the degree of coordinated economic development between urban and rural areas and the efficiency of the flow of resources, to determine whether the income gap between urban and rural areas is narrowing, as well as the rural industry in the development of the food industry is still predominantly, the digital marketing pathway to enter the county and township agricultural products development or with modernization and development to achieve the transition to the development of economic crops, etc [21].

Social dimension: This dimension focuses on the balanced allocation of resources between urban and rural areas in such areas as education, medical care and public transportation. In recent years, Jiangsu Province has actively promoted the "Integrated Urban and Rural Education Development Plan", improving the allocation of urban and rural education resources by optimizing the allocation of education resources and promoting distance education. In terms of health care, Jiangsu has increased its investment in rural health care resources, further enhancing the accessibility of health care services in both urban and rural areas. These public service equalization policies have directly contributed to the improvement of rural residents' quality of life and helped to promote the realization of urban-rural integration at the social level [22].

Ecological dimension: With the advance of urbanization and industrialization in Jiangsu Province, the ecological dimension is playing an increasingly important role in the evaluation of urban-rural integration. In Jiangsu Province, ecological protection through the implementation of the "beautiful countryside construction" and "green agricultural development" strategy reduces the ecological damage in rural areas while encouraging the development of eco-agriculture and environmentally friendly rural tourism. For example, the Huaihe River Ecological Economic Zone in northern Jiangsu Province, mainly in the vast ecological and agricultural areas, Hongze Lake, Gaoyou Lake, Lake Baima and other lakes are densely populated, and actively promote the development of agriculture on an appropriate scale and the development of large-scale agricultural landscape tourism industry, the formation of an ecological green lung area of the countryside matrix; upholding the concept of smart contraction, the population will be guided into the towns and cities, and promote the equalization of the per capita possession of the development [23].

3. Suggestions for Integrated Urban and Rural Development in Jiangsu Province

3.1. The economic pillar promotes new urbanization and rural revitalization

To promote economic development that integrates urban and rural areas, Jiangsu Province needs to focus on strengthening regional synergies and economic compensation mechanisms. By establishing industrial cooperation zones between economically developed areas in southern Jiangsu and less developed areas in northern Jiangsu, promoting financial transfer payments and cross-regional land index trading, it will promote the optimization of resource allocation efficiency. Accelerating the process of agricultural modernization should not be delayed, promoting precision agriculture and smart agricultural technology to enhance agricultural production efficiency and reduce resource waste. In order to further activate rural economic vitality, support should be given to entrepreneurship in returning to the countryside, encourage rural innovation and entrepreneurship, and provide policy and financial support for green agriculture, rural e-commerce and other areas, thereby injecting development momentum into the countryside.

3.2. Social and public assistance for the combined development of new towns and rural revitalization

The Jiangsu provincial government should further improve the equalization of public services in urban and rural areas, focusing on upgrading the health, education, and social security systems in rural areas to ensure that the quality of services is gradually approaching urban standards. Transportation infrastructure is the link between urban and rural areas, and urban and rural road networks need to be strengthened to make commuting easier for residents. At the same time, attention should be paid to reforming the household registration system to simplify the process of citizenship for the agricultural transfer population, so that migrant workers in cities can enjoy urban social benefits on an equal footing. Emphasis should be placed on the cultural effects between urban and rural areas, and a harmonious social atmosphere should be established, both by vigorously preserving and passing on traditional rural culture and by developing cultural tourism projects to promote the integration of cultural identity between urban and rural areas, enhance the cultural attractiveness of rural areas and strengthen the sense of identity, and achieve culturally empowered rural revitalization.

Ecology and the integration of new towns and villages with development and revitalization of rural areas

In the ecological field, Jiangsu Province needs to promote land use and environmental management according to local conditions. For ecologically sensitive areas, strict land protection policies should be implemented to promote land consolidation and ecological restoration of degraded areas. The development of a green economy is particularly crucial, and a win-win situation for economic development and environmental protection should be achieved through support for renewable energy, waste resource utilization and low-carbon agriculture. At the same time, it is also necessary to establish sound ecological compensation mechanisms, such as compensation for water source protection and carbon emissions trading mechanisms, to promote the rational flow of ecological value within the region. The resilience and sustainability of urban and rural ecosystems can be further enhanced by strengthening green infrastructure, such as wetland restoration and the construction of ecological corridors.

3.3. Advice to Jiangsu Province on the Current Situation of Urban and Rural Development in Japan and the United States

Grass-roots autonomy is crucial to economic development with local characteristics. In the process of rural revitalization in Japan, local self-governing organizations, non-profit organizations and individual farmers have played a key role. They have diversified their economic models and achieved sustainable community development through autonomous exploration, such as the adaptive use of abandoned houses, the development of small-scale agriculture, and cultural and creative industries, among other initiatives. When Jiangsu Province promotes urban-rural integration, it should fully stimulate the initiative of the grassroots and encourage localities to vigorously develop special industries based on their own resource advantages and cultural characteristics. Instead of relying solely on large-scale policy guidance and infrastructure construction, the focus should be on enhancing the self-development capacity of townships and communities as well as the accumulation of social capital. For example, some rural areas in Jiangsu with unique history and culture or natural resources can learn from the successful experience of the Japanese countryside, dig deep into the local characteristics, and actively develop rural tourism, folk culture experience and other industries, so as to form a differentiated competitive advantage and promote the development of the rural economy in the direction of diversification.

Government departments need to respond flexibly to demographic changes. The concept of "relational population" proposed by Japan has brought rich social, cultural and economic capital to the countryside by attracting temporary residents who do not live or participate in rural activities on a regular basis, building a non-traditional structure of population mobility. Jiangsu Province is also facing the challenges of demographic changes, such as increasing aging. In the process of urban-rural integration and development, effective strategies to adapt to demographic changes should be actively explored to attract all kinds of talents to flow into the countryside, including encouraging urban residents to go to the countryside for entrepreneurship, pension and leisure, etc., so as to promote two-way urban-rural population mobility and to inject new vitality into the development of the countryside. At the same time, it is necessary to pay great attention to the series of problems caused by the rural exodus, strengthen the care and protection of vulnerable groups such as children and the elderly left behind in the countryside, further improve public service facilities in the countryside, and effectively improve the quality of life in the countryside, so as to enhance the attractiveness of the countryside to the local population.

The systemic and coordinated nature of urban-rural integration should not be overlooked in this new phase. In the United States, urban-rural integration has achieved certain results in infrastructure construction, personnel mobility and policy initiatives, but there are also large structural differences. When Jiangsu Province promotes urban-rural integration, it should pay great attention to systematicity and coordination, not only continuing to strengthen infrastructure construction, but also paying close attention to the balanced allocation of public services such as education, medical care and culture, as well as the protection and governance of the ecological environment. For example, in the construction of transportation infrastructure, it is necessary to further optimize the urban and rural road network, improve the convenience and accessibility of urban and rural transportation, and vigorously promote the flow of factors between urban and rural areas; in the area of public services, it is necessary to increase the investment in rural areas, gradually narrow the gap between urban and rural public services, and truly realize the equalization of basic public services in urban and rural areas; in the area of ecological environmental protection, it is necessary to draw on the beneficial experience of the U.S. in the area of ecological governance and strengthen regional cooperation. In terms of ecological environmental protection, it is necessary to fully learn from the useful experience of the United States in ecological governance, strengthen regional cooperation, jointly tackle ecological environmental problems, and promote the integrated development of urban and rural ecology.

Rational planning and guidance of urban and rural development are key. The United States has a relatively decentralized approach to urban-rural integration, which is mainly promoted by local and state governments, with a more pronounced market-driven role. China's new urbanization and rural revitalization planning, on the other hand, has a top-down, government-led approach. In the process of urban-rural integration and development in Jiangsu Province, the government's role in planning and guidance should be fully utilized, and market mechanisms should be combined to formulate scientific and reasonable urban and rural development plans. The government should strengthen the macro-control of urban and rural development, rationalize the layout of industries, and effectively avoid homogeneous competition between urban and rural industries. At the same time, it should attach great importance to the implementation and supervision of planning to ensure that all policies and measures can be effectively put into practice, so as to improve the quality and effectiveness of urban-rural integrated development.

Social and cultural integration is significant. In the United States, urban-rural migration is mainly based on voluntariness, which has brought about the phenomenon of “lifestyle migration,” which has promoted social integration to a certain extent but has also triggered problems such as middle-classization and displacement of rural residents. In Jiangsu Province, in the process of promoting urban-rural integration, great importance should be attached to social and cultural integration, strengthening exchanges and interactions between urban and rural areas, and promoting mutual understanding and identification between urban and rural residents. Emotional ties between urban and rural residents can be enhanced by carrying out diversified cultural activities and strengthening educational exchanges. At the same time, traditional rural culture should be effectively protected and inherited, rural cultural values should be explored in depth, and rural cultural brands with local characteristics should be carefully crafted, so as to continuously enhance the cultural attractiveness and cohesion of the countryside.

4. Conclusion

This paper reveals the core mechanism and research hotspots of the combination of new urbanization and rural revitalization through literature review and emphasizes the important role of the coupled coordination theory in analyzing the interaction of urban and rural factors and the optimal allocation of resources. On the one hand, existing research confirms that the key to promoting urban-rural integration lies in improving policy support, optimizing the factor flow mechanism, and balancing the distribution of resources between regions. On the other hand, the current research needs to be further improved in terms of the scientific nature of the indicator system and the regional adaptability of the urban-rural integration path. Future research should strengthen the exploration of evaluation models for urban-rural integration, deepen the study of regional differences, and further integrate economic, social and ecological perspectives to construct an operational and comprehensive evaluation framework to promote the high-quality advancement of urban-rural integration development.