With the development of urbanization, promoting the citizenization of migrant workers and improving the quality of employment has become an important goal of China's urbanization strategy in the new era. Affected by the COVID-19 pandemic, the problem of informal employment stands out even further. Starting with an examination of the relationship between new urbanization and informal employment, this study draws on the data from population census and the China Labor-force Dynamic Survey (CLDS) to estimate the scale of urban informal employment in China and analyze its spatial and sectoral characteristics. It then identifies the main social integration problems faced by informal workers and discusses some policy options. It is found that urbanization and informal employment are interrelated. Informal employment provides job opportunities for rural migrants with the inability to find formal jobs in cities and urban workers who are unemployed, playing a role in alleviating employment and poverty problems. It is argued that the new urbanization with the principle of putting people first should be concerned with the social integration of informal workers with the aim to promote their citizenization. According to the estimation based on multi-source data, the number of informal workers is 138 million-155 million, accounting for 33.2%-44.7% of urban employment in China. The unobserved/unregistered informal workers are the majority. The distribution of informal employment is characterized by the spatial pattern that the scale of informal employment decreases from the eastern to the central and the western parts of China. In terms of employment types, most informal workers are employed in enterprises. Informal employment in China is mainly concentrated in the sector of wholesale, retail trade, and catering, followed by the sectors of residential service, repair, and other services and manufacturing industry. Informal workers are faced with difficulties in social integration, including job precarity, income instability, social marginalization due to population registration restriction, limited access to public services, and vulnerability to crises. It is recommended that policy intervention should pay attention to improving the quality of informal employment and promoting social integration of informal workers in the future.

The twenty-first century is an urban century, and high quality urban development is critical for regional and global sustainable development. China has experienced a very rapid urbanization, with its urbanization rate increased from 17.9% in 1978 to 60.6% in 2019. This rate will further increase to more than 70% in 2030, with most of the population lives in cities. Cities are the engine of economic development in China. With 7% of the terrestrial area, they produced 70% of the national gross domestic product (GDP), and the urban agglomerations even concentrated more population and GDP in China. The health and sustainability of cities and urban agglomerations therefore will determine China's development quality and progress in the future. To identify the levels of their development, the issues they face, and the gaps with other cities in China and internationally, we need to quantitatively evaluate their development. In this study, we systematically reviewed the evolution of the theories and index systems of sustainable development evaluation, examined the methodology of urban sustainable development evaluation based on the United Nation's Sustainable Development Goals framework, and proposed an approach to evaluate the level of sustainable development of cities and urban agglomerations. Finally, we suggest an approach to create a urban development dashboard from platform building, big data processing, and index monitoring and releasing. This approach based on the United Nation's Sustainable Development Goals can provide the focal city a reference from other cities, make it possible to compare cities in different regions, and contribute to identifying development direction and existing problems.

Along with the urban industrial structure adjustment and the development of the rural economy, a large-scale backflow of inter-provincial migrant workers gradually emerged, which had a tremendous impact on China's economic and social development. The spatial differences and influencing factors of inter-provincial migrant workers' backflow intention are vital issues, particularly in predicting the changing demographic trends and understanding the migrant population's needs and demands. Drawing on data from the 2016 China Migrant Population Dynamic Survey, this study discussed the spatial distribution and influencing factors of 82846 inter-provincial migrant workers from 31 provinces of China's mainland using a binary Logistic regression model. The results are as follows: 1) Older migrant workers with lower education level or without stable marital status seem to have stronger backflow intention. 2) The distribution of backflow intention presents a remarkable spatial differentiation. Among the three main geographical regions, the backflow intention of migrant workers currently in the eastern and western regions of China is stronger while the migrant workers who came from the central region express their clear willingness to return. 3) Backflow intention is influenced by personal factors of migrant population, their migration characteristics, family factors, and institutional factors. For all the factors, age, marital status, education, years of working after migration, migrating with family or not, family income, housing condition, and social security system are significant forces that shape the spatial pattern of inter-provincial migrant workers' backflow intention in China.

As an important attribute of rural production spatce system (RPSS), resilience is a sustainable ability, including persistence (system maintenance), adaptability (system evolution), and transformability (system mutation) in response to internal and external environmental disturbances. It is the only pathway to realizing rural revitalization and sustainable development in rural China. Based on the international and Chinese research and RPSS attributes, this study explored the connotations and essence of RPSS resilience. Meanwhile, based on the epistemology and ontology of philosophy, a qualitative model of RPSS resilience was developed considering the five dimensions of disturbance, stakeholders, state of system, objective of system, and ability of resilience. Applying this qualitative model, this study identified four main research contents of RPSS resilience, which include disturbance recognition and vulnerability analysis, the feedback relationship between vulnerability and resilience, resilience assessment and threshold effect analysis, and the development of adaptive governance system. This article also presented some future research focuses, which include new multidisciplinary and integrative methods, spatiotemporal scale association and multi-dimensional factor transmission, and the integrated development of adaptive governance system of stakeholders. This study may be helpful for the prevention and reduction of major risks and for promoting the development of rural revitalization and rural sustainable development in rural China.

Along with the rapid progress of urbanization, dramatic changes in the ecological environment and profound changes in the social and economic systems have made issues related to China's urban and rural development more prominent. Urban and rural governance faces new challenges. The concept of social-ecological resilience may shed some light on changes in the practice of rural-urban governance, but there is a lack of research on the relationship between them. Focusing on major issues of urban and rural development in China, this study clarified the relationship between social-ecological resilience and urban and rural development, and constructed a logical framework of rural-urban governance from the perspective of social-ecological resilience. The framework aims to promote urban and rural integration and sustainable development by introducing the key characteristics of social-ecological resilience (coupling, self-organization, and learning) into rural-urban governance mechanisms (planning, participation, and policy). In the future, social and ecological issues should be taken into overall consideration in rural-urban governance, with the idea of human-earth system coupling. A multiple-tiered network of coordinated rural-urban governance should be established. Attention should be paid to the cultivation of cooperation and innovation of the participants at different scales, especially to the construction of learning and adaptability of urban and rural communities. In practice, it is necessary to make full use of spatial planning, to incorporate ecosystem services into rural-urban spatial governance and take them as a priority. The goal of enhancing the resilience and adaptive capacity of urban and rural areas to uncertain challenges will be achieved by coordinating the relationship between ecosystem services and human well-being.