Spatiotemporal evolution of prehistoric Neolithic-Bronze Age settlements and influencing factors in the Guanting Basin, northeast Tibetan Plateau

For almost two decades, the relationship between prehistoric natural disasters that struck the Guanting Basin in northeast Tibetan Plateau and the destruction of Lajia, an archeological site, has attracted scholarly attention and been widely discussed. Whereas most studies have focused on the impacts of disasters on a single site within the Guanting Basin, few have examined patterns of spatiotemporal evolution of human settlements from the Neolithic to the Bronze Age. Consequently, there is a lack of clarity on the processes and mechanisms underlying the evolution of prehistoric human-land relationships in the Guanting Basin. We therefore examined spatiotemporal variations in settlements in the Guanting Basin during the period, based on the locations, altitudes, and areas of archaeological sites. We found that four sites were located on the third terrace of the Yellow River during the late Yangshao period(5500–5000 cal yr BP) and distributed within a small area. During the period between the Majiayao and Qijia cultures(5300–3600 cal yr BP), the number of sites evidently increased and the scale and distribution of settlements expanded, with settlements generally shifting toward the lower elevation areas of the Guanting Basin.During the Xindian period(3400–2700 cal yr BP), the number and scale of sites showed a downward trend and the distribution of settlements contracted. The Xindian settlement underwent altitude-based spatial differentiation, with some groups moving to areas at higher altitudes and others remained in lower altitude areas. Moreover, we found that the number, scale, and distribution range of Neolithic and Bronze Age sites in the Guanting Basin were closely related to the evolution and distribution patterns of prehistoric cultures in the regions of Gansu and Qinghai, which were further affected by climate change and agricultural development. Furthermore, there is no evidence that the altitudinal distribution pattern of Neolithic and Bronze Age settlements in the Guanting Basin was influenced by paleofloods rather it was primarily influenced by changes in subsistence strategies.

The process and driving forces of rural hollowing in China under rapid urbanization

Rural hollowing is a recent geographic phenomenon that has received significant attention in China, which is experiencing rapid urbanization. It has led to the wasteful use of rural land resources, and imposed obstacles on the optimization of land use and coordinated urban-rural development. Rural hollowing has various forms of manifestation, which refers to the neglect and vacancy of rural dwellings, both of which can lead to damage and ultimate abandonment of rural dwellings. Damaged dwellings have different degrees of destruction, ranging from slight, moderate to severe. The evolutive process of rural hollowing in general has five stages, i.e., emergence, growth, flourishing, stability, and decline. Based on the combination of both regional economic development level and its physiographic features, the types of rural hollowing can be categorised as urban fringe, plain agricultural region, hilly agricultural region, and agro-pastoral region. Especially, the plain agricultural region is the most typical one in rural hollowing, which shows the spatial evolution of rural hollowing as a ＂poached egg＂ pattern with a layered hollow core and solid shape. Furthermore, the driving forces behind rural hollowing are identified as the pull of cities and push of rural areas. In particular, this paper identifies contributors to rural hollowing that include rural depopulation in relation to rapid urbanisation and economic change, land ownership and land use policy, and institutional barriers.

Overview and progress of Chinese geographical human settlement research

Increasing Chinese urbanization and industrialization has prompted greater attention to the study of human settlement and the human-land relationship in the fields of geography, architecture, and urban planning. We used bibliometric methods and statistical software to review 180 articles on human settlement in 16 Chinese geographical journals. We found that Chinese geographical human settlement research is characterized by the following：（1） Most research focuses on human settlement extension, valuation indicators, models for urban and rural settlements, theoretical exploration and the planning practices of single-factor, human settlement and complex, geographical livability in macro-scale, urban settlement differentiation and ideal patterns in medium scale, the comprehensive evaluation of settlement environment, and the planning of community units in micro-scale, community settlements; socio-cultural investigation and warnings about advancing human settlement.（2） No progress has been made in synthesizing and integrating method systems. PSR models and DPSIR models are used for targeting mechanisms, while the standard settlement evaluation system was composed of physical ＆ economic indicators by questionnaire surveys. On the other hand, spatial clustering based on GIS has been a frequent focus in recent years. Pioneering research on human settlement and theoretical systems within the context of China＇s urbanization and industrialization will provide guidance on the sustainability of Chinese cities and regions. The following five aspects require greater attention：（1） Natural suitability research on human settlement, and a survey of human settlement demands to reflect the range of different demands concerning ecologically suitable settlements in urban environments, the corresponding valuation indicators, systems, and evolution, and the impact of the residents＇ socio-economic attributes.（2） Spatial-temporal evaluation and sustainability research on urban and rural human settlement at various scales, focusing on evolution and spatial differen-tiation at various scales such as city clusters and comparisons between cities, within the cities and communities.（3） Development of theory and technology for human settlement evolution research, including detection technology and methods, data mining measures, and forecasting and emulation of regional and urban human settlement evolution processes, mechanisms and patterns.（4） Research on the control of human settlement that focuses on optimization, patterns, and policies for effective management and development.（5） Estimating the human settlement system service value and establishing suitable human settlement systems, including social, economic, cultural and ecological service values.