The number of urban vitality assessment studies is rising continuously, owing to the emergence of geographic data. The current literature focuses primarily on evaluation, rather than implementation, of urban vitality. Hence, a scoping review and research agenda are needed for urban vitality research to be more practical. This study aims to fill the research gap by exploring the content and methods of vitality assessment that can make urban vitality research more compatible with policy, planning, and design practice. We chose the neighborhood scale, which is the most practical initiative unit for vitality enhancement. We discovered that the gaps between the current research and practice primarily lie in the diversity of research subjects, the authenticity and comprehensiveness of vitality measurement, and the multi-domain of impact factor analysis. On this basis, we classified the following expandable aspects: (1) multi-type, multi-dimensional, multi-temporal, and implementation-adaptive vitality evaluation; (2) methods reflecting high-quality social interactions and the perceptions of vulnerable groups; (3) how design and urban management impacts vitality; and (4) the synergistic effects of multiple indicators on vitality. Overall, the research content and methodology presented in this paper can help neighborhood-scale vitality assessment to provide more meaningful insights for policy makers and practitioners.

As a new mode for Chinese overseas investment and a growth pole for industrialization and urbanization of the host countries, the overseas economic and trade cooperation zone (OETCZ) or overseas free economic zone (OFEZ) of China plays an important role under the Belt and Road Initiative. With the rising attention on OETCZ, studies regarding OETCZ have also increased. However, there is a lack of studies reviewing this topic’s progress, challenges and future directions. This paper employs a systematic review to examine the literature on the OETCZ along the Belt and Road, based on domestic and overseas studies. The results show that domestic studies account for a large proportion of the collected literature, compared to overseas studies. Interdisciplinary research focus includes inductive case studies from a classification perspective, deductive studies based on cultural and institutional perspectives, trade network and bilateral trade relations based on the perspectives of international trade and regional economy, spatial planning studies from urban planning perspective, and overseas comments and earlier studies on Japan’s and Singapore’s overseas parks from the geopolitical and international political perspectives. Despite diverse research contents and dramatic progress, limitations exist in current OETCZ-related studies, including a lack of exploration of the mechanism, questions and concerns from overseas scholars, sustainable development and other problems. Future studies should broaden and deepen research insights, including the “overseas free economic zones (OFEZ)” as a general designation to cover all other types of OETCZs, studies on the primary conditions of host countries, exploration of the theoretical issues behind China’s OETCZ, comparative study of OETCZs such as management structures, profit models, environmental standards and legal systems as well as popular issues questioned internationally.

Under the framework of ecological civilisation, the formulation of territorial spatial planning (TSP) and improvement of spatial governance systems are of great practical significance. Since the founding of the People’s Republic of China, land-use planning (LUP) has experienced profound changes, and tremendous research efforts have been made in that field. However, systematic studies on LUP history are scarce. To bridge the existing gap, this study traced back to the emergence of LUP, described its practice stages, and analysed the evolution of its classification system and methods. Further, the three rounds of general LUP practice and the current TSP over the past 40 years of the reform and opening-up have been discussed. The evolution of LUP was found to be closely related to economic development and could be broadly divided into four stages. The development of land-use classification in China has been slow and can be divided into five stages according to the evolution of the land classification system and important historical events. The development of LUP methods can be divided into two stages, before and after 1978. Since the economic reform, China has successively conducted three rounds of general LUP under different institutional and policy backgrounds. Future development should aim to innovate the theories and methods of TSP with Chinese characteristics and promote the study of village planning and the construction of TSP systems to achieve rural revitalisation and ecological civilisation.

Soil particle-size fractions (PSFs), including three components of sand, silt, and clay, are very improtant for the simulation of land-surface process and the evaluation of ecosystem services. Accurate spatial prediction of soil PSFs can help better understand the simulation processes of these models. Because soil PSFs are compositional data, there are some special demands such as the constant sum (1 or 100%) in the interpolation process. In addition, the performance of spatial prediction methods can mostly affect the accuracy of the spatial distributions. Here, we proposed a framework for the spatial prediction of soil PSFs. It included log-ratio transformation methods of soil PSFs (additive log-ratio, centered log-ratio, symmetry log-ratio, and isometric log-ratio methods), interpolation methods (geostatistical methods, regression models, and machine learning models), validation methods (probability sampling, data splitting, and cross-validation) and indices of accuracy assessments in soil PSF interpolation and soil texture classification (rank correlation coefficient, mean error, root mean square error, mean absolute error, coefficient of determination, Aitchison distance, standardized residual sum of squares, overall accuracy, Kappa coefficient, and Precision-Recall curve) and uncertainty analysis indices (prediction and confidence intervals, standard deviation, and confusion index). Moreover, we summarized several paths on improving the accuracy of soil PSF interpolation, such as improving data distribution through effective data transformation, choosing appropriate prediction methods according to the data distribution, combining auxiliary variables to improve mapping accuracy and distribution rationality, improving interpolation accuracy using hybrid models, and developing multi-component joint models. In the future, we should pay more attention to the principles and mechanisms of data transformation, joint simulation models and high accuracy surface modeling methods for multi-components, as well as the combination of soil particle size curves with stochastic simulations. We proposed a clear framework for improving the performance of the prediction methods for soil PSFs, which can be referenced by other researchers in digital soil sciences.

Urban shrinkage is the process of population loss, industrial and functional decline, and eco-environmental deterioration due to various natural and human factors that occur once a city’s development reaches a certain point. It is an external manifestation of positive or negative changes in an urban economy, society, culture, resource use, and sustainability. Urban shrinkage is a new feature of global urbanization as well as a frontier of international and Chinese research. It has attracted widespread attention from academics in China and overseas, becoming an emerging trend that has spread from developed countries to underdeveloped ones. Research on and responses to urban shrinkage have also become new tasks of China’s new urbanization strategy. Our review of the existing literature reveals that there are significant temporal and spatial differences in research by Chinese and overseas scholars on urban shrinkage. Urban shrinkage studies have paid scant attention to interactions with the eco-environment, with analyses of urban shrinkage mechanisms and factors largely focusing on economic and social development factors; and urban shrinkage index analyses have tended not to include eco-environmental quality and environmental pollution indicators. The key tasks for future urban shrinkage research include the following: to conduct in-depth research on the mechanisms and driving factors of urban shrinkage to reveal the essence of urban shrinkage; to discover the principles behind interactions between urban shrinkage and the eco-environment, as well as to analyze the eco-environmental effects of urban shrinkage; to construct an index system for evaluating the extent, monitoring and providing warnings of, and containing urban shrinkage; and to research urban shrinkage coping strategies under different circumstances and carry out experiments and demonstrations according to local conditions.

The precision remediation and redevelopment of contaminated sites are crucial issues for improving the human settlement and constructing a beautiful China. Three-dimensional delineation of soil pollutants at contaminated sites is a prerequisite for precision remediation and redevelopment. However, a contaminated site is a three-dimensional complex system coupling multiple spatial elements above- and under-ground. The complexity incurs high uncertainties about the three-dimensional delineation of soil pollutants based on sparse borehole and spatial statistics and inference models. This paper first systematically reviewed the objectives of fine three-dimensional delineation of soil pollutants, the sampling strategies for soil boring, the commonly used models for delineating soil pollutants, and the relevant cases of applying these models at contaminated sites. We then summarized the effects of borehole data and three-dimensional models on soil pollutants’ delineation results from biased characteristics and nonstationary conditions. The present research status and related issues on correcting the biased characteristics and nonstationary conditions were analyzed. Finally, based on the problems and challenges, we suggested the three- dimensional delineation of soil pollutants in the underground “black box” for future research from the following six priority areas: multi-scenarios, nonstationary, non-linearity, multi-source data fusion, multiple model coupling, and the delineation of co-contaminated sites.

The terrestrial hydrological process is an essential but weak link in global/regional climate models. In this paper, the development status, research hotspots and trends in coupled atmosphere-hydrology simulations are identified through a bibliometric analysis, and the challenges and opportunities in this field are reviewed and summarized. Most climate models adopt the one-dimensional (vertical) land surface parameterization, which does not include a detailed description of basin-scale hydrological processes, particularly the effects of human activities on the underlying surfaces. To understand the interaction mechanism between hydrological processes and climate change, a large number of studies focused on the climate feedback effects of hydrological processes at different spatio-temporal scales, mainly through the coupling of hydrological and climate models. The improvement of the parameterization of hydrological process and the development of large-scale hydrological model in land surface process model lay a foundation for terrestrial hydrological-climate coupling simulation, based on which, the study of terrestrial hydrological-climate coupling is evolving from the traditional unidirectional coupling research to the two-way coupling study of “climate-hydrology” feedback. However, studies of fully coupled atmosphere-hydrology simulations (also called atmosphere-hydrology two-way coupling) are far from mature. The main challenges associated with these studies are: improving the potential mismatch in hydrological models and climate models; improving the stability of coupled systems; developing an effective scale conversion scheme; perfecting the parameterization scheme; evaluating parameter uncertainties; developing effective methodology for model parameter transplanting; and improving the applicability of models and high/super-resolution simulation. Solving these problems and improving simulation accuracy are directions for future hydro-climate coupling simulation research.