The world has entered an era of hypermobility and instability. National and social governance is facing enormous new challenges. With the rapid urbanization, the free flow of factors frequently cross borders. Governance needs to transform instability into stability, which highlights the importance of cross-border governance. The interweaving of global, regional and local scales has brought new issues of cross-border governance. Cross-border governance mainly refers to the process of making multiple subjects participate in and jointly govern public affairs through cross-region, cross-department, cross-level and cross-field. By sorting out the relevant theories of cross-border governance, this article redefines the “border”, reconstructs the theoretical logic of cross-border governance, and proposes that cross-border governance mainly involves three pairs of key categories of three scales: Heterogenization and homogenization at the local scale; deborderlization and borderlization at the regional scale; decentralization and centralization at the global scale. Taking the Yangtze River Delta as a case study, this article empirically analyzes the logic of cross-border governance at regional scale.
Against the backdrop of the China’s city-regionalism, this article systemically examines the interaction between regional spatial production and regional governance from the lens of capital, social and power territorialization. Through a case study of Shenzhen-Shanwei Special Cooperation Zone, a typical “enclave economy” in the Pearl River Delta, this article found that the regional spatial production is on one hand contingent upon the political mobilization from the superior government, on the other hand upon the market preferences of the entrepreneurs. Second, the spatial fix of regional governance upon regional spatial production is dynamically adjusted, which is guided by the capital demands. Third, the regional spatial production has co-evolved and inter-facilitated with the regional governance. All of these findings suggest that the formation of China’s city-region is essentially the manifestation of China’s state governance marked by state centrality and market instruments at the regional scale. The building of modern state governance capacity and the path dependence upon localism need a deepening motivation mechanism and institutional design.
The regional coordinated development strategy is the core strategy of China in the 21st century which emphasizes the collaborative development between core cities and periphery cities in each region to realize the shared prosperity of the whole region. At the same time, under the background of the knowledge economy, High-Tech Industrial Development Zones (HTIDZs) has provided a fundamental space for cities to participate in the regional labor division. With the advancement of the regional coordinated development strategy, it has become a compelling topic how the periphery cities can rely on HTIDZs to drive the whole city into the process of regional integration. Taking Zhongshan as an example, this paper drew on qualitative methods including literature analysis, participatory observation, and in-depth interviews to examine the specific process by which periphery cities are integrated into the new regional development pattern through spatial governance and integration strategies. To this end, over the period of November 2020 to May 2021, thirty-three policy documents, seven-month participatory observation, and seven interviews were collected and analyzed to understand how Zhongshan utilizes Zhongshan Torch High-Tech Industrial Development Zone to integrate into the synergetic development of the Greater Bay Area. Findings suggested that: 1) Zhongshan constructs the “hyper-local” HTIDZs and emphasizes that the goal of spatial governance is to serve regional coordinated development. 2) Upgrading the scale of urban service function is an essential strategy for periphery cities to integrate into the region and an effective way for Zhongshan to avoid being marginalized. The paper contributes to the exploration of the framework of spatial governance of periphery cities under the background of socialism with distinct Chinese characteristics, especially the exploration of the role of HTIDZs in periphery cities in bridging the core-periphery structure in the context of modern China. It will also help deepen the market-oriented reform in China and improve the explanatory power of human geography in urban development issues.
China is in a new stage of development to comprehensively build a socialist modern country and march towards ‘the second Centenary Goal’, and the direct risks it faces are gradually turning to potential uncertainty. It is found that the uncertainty factors of development environment, development subject and development mode are simultaneously increasing, which jointly promote the uncertainty to become an overall characteristic of Chinese society in the new stage of development. This has had an great impact on the current practice of social governance in China, resulting in suffering from multiple dilemmas at the levels of value, action, method and result. At the value level, risk thinking still dominates governance practice. At the level of action, it is naturally difficult to deal with uncertainty. At the method level, the traditional governance mechanism is difficult to normally take effect. At the result level, uncertain consequences of social governance occur frequently. In this regard, it is necessary to promote the construction of ‘resilience governance’ from the dimensions of subject empowerment, mechanism innovation and system creation based on a new uncertainty thinking. What need to be done to get out of the dilemma of China’s social governance in the new development stage and improve the efficiency of governance, resilience governance would be helpful as it provides important guidance for coping with uncertainties. More specifically, what should be done, first of all, is to cultivate the uncertainty thinking and vitalize the concept of ‘resilience governance’. In the second, it is supposed to strengthen the empowerment of the subject and build the basis for action of resilience governance. Thirdly, innovating governance mechanisms and building a ‘modular’ governance approach should be taken into account. And finally, strengthening the establishment of the system and promoting the deep change of governance form are necessary. However, the construction of resilience governance model needs multi-disciplinary, multi-subject and multi-sector cooperation. Meanwhile, uncertainty also requires an integrated analysis across disciplines. At present, it is urgent to take uncertainty as the theoretical guidance, social governance as the practical platform, and adopt an ‘integrated disciplinary approach’ to realize the integration among different disciplines. Therefore, we hope that this article will inspire more scholars to think about ‘uncertainty of social development’ from an interdisciplinary perspective, and provide more practical and forward-looking ideas and methods for the transformation of social governance in China at the new stage of development.
The nature reserve is the core of ecological civilization construction. Conflicts between the local life of community residents and the protection of resources have become the key to sustainable development in the region. Taking Qionghai National Wetland Park as a study case, this article employs semi-structured interview and participatory mapping to investigate local residents. Finally, 308 sets of questionnaire and map are collected and 737 spatial points are mapped. By combining qualitative analysis with spatial analysis, residents’ perceived conflicts and its spatial response are analyzed. Furthermore, this article discusses the formation mechanism of spatial response residents’ perceived conflicts. Results suggest that there are 7 conflict categories, including insufficient livelihood guarantee, compression of activity space, absence of policy, weakened emotion support, inconvenience of daily life, environmental quality decline and production contradiction. The first five conflict categories accounted for 76.4% of the total, constituting main conflict contents perceived by residents. Spatial response of conflicts is a common reflection of residents’ attention to and dissatisfaction with conflicts. In spatial, the conflict distribution of high-value areas is relatively independent and low-value areas are generally continuous. The higher-level areas of conflicts’ spatial response have a higher degree of conflict exposure and management priority. Multiple factors can exert influence on conflicts’ spatial response. In Qionghai National Wetland Park, tourism development and livelihood strategy are most influential factors. Geodetector results display that although the impact of traffic travel management, residential area type, land use type and house construction management are less, they have an important explanatory effect on conflicts’ spatial response. Overall, these factors reflect ecological construction, tourism development, institution arrangements and socioeconomic status in Qionghai, which provides spatial response primitive, external driving, structural and social force.
With the acceleration of the development and update of smart technology, various smart technology applications and services have penetrated different aspects of residents’ daily lives. Resident activities are being affected by disruptive smart technologies. Understanding the characteristics of smart technology and the new changes in residents’ activities is essential for analyzing the impact of smart technology on residents’ activities. This article summarizes the development of technology and the research focus in the corresponding process from the perspective of technological evolution and residents’ activities. From the emergence of traditional information technology to the emergence and rapid development of information and communication technology, and then to the current new generation of smart technology, technology has shown an interactive development trend. As two classic research issues, the mobility of residents and the space-time constraints of residents’ activities have always been the focus of scholars’ attention. On this basis, this article sorts out the changes in urban residents’ activities under the influence of smart technology from four aspects: smart travel decision-making, new residents’ activity forms, new space utilization characteristics, and social and cultural effects. Furthermore, the ever changing relationships between urban residents, smart technology and urban space are interpreted. A highly smart organism is formed under the interaction among urban residents, smart technology, and urban space, which is guided by residents’ needs, assisted by the empowerment of smart technology and the high-quality space carrier. Finally, a research framework for the impact of smart technology on resident activities is constructed, and the research contents that needs to be focused on in the future are sorted out from three aspects: characteristics and models, mechanisms and effects, and prediction and simulation, in order to provide a reference for the research on resident activities under the background of smart technology.
The fine spatial distribution of regional population in future plays an important role in constructing relevant future plans for country and regions. More previous researches focused on the spatial distribution of current regional population, while little deals with the fine spatial distribution of future population. In this article, taking the fine simulation of spatial distribution of population in 2030 for counties in the Pearl River Delta (PDR) as an example, we firstly simulated future population and land use type using the methods of cohort-component and CA-Markov model, respectively, according to the census data and current land use maps. And combined with the big data of Point of Interest (POI), a model that simulates the fine spatial distribution of regional population in future was constructed by the multisource fused method. The results are as follows: Firstly, the absolute relative error is mainly less than 5% when predicting demographic data of PDR with the method of cohort-component. The Kappa coefficient of land use simulation in PDR by CA-Markov model is as high as 0.97. Secondly, the R2 for fitting line between the simulated spatial distribution of population data and the actual population data reaches 0.90, which is better than Worldpop data set and demonstrates the advantage of big data of POI in the fine spatial distribution simulation of population. Thirdly, the spatial distribution of population in PDR decreases from the center to the periphery, performing the significant spatial difference. Meanwhile, 70% of the population concentrates in the core cities of Guangdong-Hong Kong-Macao Greater Bay, the core cities mainly include Guangzhou, Shenzhen, Dongguan and Foshan. The spatial distribution of population in PRD was significantly different and relatively stable, and showed a trend of expansion from the center to the periphery, while the overall expansion was small. This study puts forward a multisource fused method for the fine spatial distribution of regional future population, and provides scientific basis and reference for the region to make relevant development plans in the future.
This paper constructs the airline sub-network, the high-speed rail sub-network and the airline-high-speed rail composite network based on airline and high-speed rail timetable data in 2009, 2014 and 2019. Social network analysis and principal component analysis were used to obtain the comprehensive traffic index and compare the dynamic evolution characteristics of the three networks. The results show: 1) The urban network structures under the two sub-networks are different. Airline networks provide a fast connection to core cities for long-distance travel. The relevant urban network structure presents a diamond structure with four dynamic pivots. With the rise of the central and western cities, urban networks under airline networks tends to be balanced. At the same time, the high-speed rail network connects major cities in the central and eastern regions, along the development of trunk lines of high-speed rail, the urban network structure evolves from point to corridor and finally to belt distribution. 2) According to comparative analysis, it is found that the expansion of high-speed rail network has a squeezing effect on airline networks. High-speed rail has gradually become a dominant transportation mode within 1500 km. Meanwhile, the dominant travel distance of airlines has been expanded. According to the composite network analysis, high-level administrative cities and economically developed cities occupy the dominant position, the importance of cities in the central and western regions is rising, and that of cities in the northeast is declining. The urban network structure under the composite network shows a transition from point to line and finally to area development. The differences between the cities on both sides of the Hu Line as the boundary still exist. The eastern and central cities in the composite network have shifted from being dominated by airline to high-speed rail connections, while the western region is still dominated by airline connections.
With the rapid development of information and communication technology (ICT) trade, the composition of trade presents a growing trend of diversification, complexity and networking. Therefore, it is necessary for us to conduct a study in a systematic way on the structure of ICT trade network. On account of the ICT trade data from the United Nations Conference on Trade and Development (UNCTAD) database from 2000 to 2018, this article constructs the global export trade network for manufacturing equipment (Computers and peripheral equipment, communication equipment and consumer electronic equipment) and electronic components using binary and weighted methods. On the basic of the comprehensive analysis of the structural characteristics of the ICT trade network, this article uses the QAP method to explain the structural evolution and the influencing factors of the ICT export trade network. The results show that: 1) The network densities of the export trade of manufacturing equipment and electronic components are both very high, which shows that ICT trade is closely related to countries (regions) around the world; 2) China has become the core node of the manufacturing equipment export trade network, what’s more, developed economies still occupy the main market; In the electronic components export trade network, there are investment-driven development. ‘Agglomeration’ is another phenomenon emerging in the electronic component export trade network. China also occupies an important position in the electronic components export trade network; 3) The multi-dimensional distance factor can explain 18% of the structural change of the export trade network of manufacturing equipment; The explanatory power of multidimensional distance factor to the change of electronic component export trade structure can reach 15%. The conclusions of this paper can provide a basis for China’s ICT industry to participate in global trade policies.
According to the current situation of rural settlements development in underdeveloped areas, we carry out the research on village scale rural settlements evaluation and reconstruction type identification, which is of great significance to clarify the internal differences and multiple trends of rural settlements development and promote rural revitalization. Taking Weidian Town in the loess hilly area of Longzhong as the research object, this artical constructs the rural ‘basic life circle’ and the evaluation index system of layout suitability, based on the analysis of the village detailed survey database and the spatial layout of rural settlements. Then we identify the types of rural residential reconstruction and propose countermeasures. The results show that: 1) Affected by natural endowments and traffic factors, the rural residential area in Weidian Town presents the characteristics of ‘concentrated mainly, dispersed supplemented, scattered gathering’, and the landscape differentiation is obvious. 2) There is a significant difference in the area and quantity of residential areas covered in 10-minute and 20-minute life circle. It is easier for residential areas to obtain public service facilities in relative agglomeration states. 3) The distribution of rural residential areas is suitable. The suitability of residential areas is mainly medium and high, which include 1742 patches, accounting for 85.18% of the total number of residential areas. 4) By using the two-dimensional combination matrix of spatial dislocation analysis, the results of superposition of ‘basic life circle’ and layout suitability evaluation of rural residential areas can be divided into three types: agglomeration and promotion type, guidance and development type and relocation support type. Agglomeration and promotion type can be regulated according to the development idea of ‘improving quality and efficiency, allocating according to demand, leading villages by town and focusing on development’; Guidance development type follow the development idea of ‘consolidating advantages, classifying adjustment, supplementing shortcomings, and gradually advancing’ to optimize the interior of residential areas; Relocation support type should proceed reasonable demolition or give financial support to the villagers based on the principle of ‘active guidance, respect for the will, policy support, should be dismantled as much as possible’.
As a developed coastal region in eastern China, Zhejiang is the pioneer for rural revitalization. Drawing upon the concepts of rural and rurality, this article constructs an evaluation system of rurality index with four dimensions: namely, economic foundation, land use, infrastructure, and social development. It evaluates the rurality index of 1218 township-level units in Zhejiang Province, and identifies the spatial differentiation characteristics of rurality. Based on this, the article develops a typology of rural development and proposes several developmental pathways for Zhejiang’s rural revitalization in the future. The results show that: 1) The spatial distribution of Zhejiang’s economic foundation, land use, infrastructure, and social development index all present significant agglomeration characteristics. 2) The overall rurality index of Zhejiang Province is low with a significant spatial pattern: the index increases gradually from the northeast to the southwest, and from the core cities to the peripheries. The low-value areas of rural index are Huzhou, Jiaxing, Hangzhou, Shaoxing, Ningbo, Zhoushan mainly around the Hangzhou Bay, and Wenzhou and Taizhou in southeastern coast of Zhejiang Province. The high-value areas of rurality index are Quzhou and Lishui in southwestern Zhejiang, as well as some neighboring areas between Jinhua and the southwest of Zhejiang. 3) There is a positive spatial correlation in the rurality index. Towns with similar rural intensity values tend to be regions adjacent with each other. The low-value clustering area of the rurality index locates in the northern and eastern coast of Zhejiang, while the high-value clustering area of the rurality index locates in the southwest of Zhejiang. 4) Zhejiang’s rural areas are differentiated with four key types: urban-effecting villages including the characteristic industrial sub-type and the business or tourism service sub-type, traditional agriculture-based villages including the coastal fishery sub-type and the inland agriculture or forestry sub-type, eco-tourism villages, and comprehensive development villages including the strong rural comprehensive development sub-type and the weak rural comprehensive development sub-type. Finally, the article puts forward several developmental paths according to the different types of rural areas, for promoting a higher-quality development of rural areas in China.
China has a unique political system and administrative system, which makes the agglomeration and allocation process of urban resources present a spatial hierarchy, and its manifestation is the urban administrative hierarchy. Important factors or resources such as capital, energy, human capital, advanced technology, infrastructure, and preferential policies, all follow a gradual distribution pattern from the central to the local, from higher to lower hierarchies. This means that the hierarchy of a city determines the size of administrative power to a large extent, which in turn affects the flow and redistribution of factor resources. Compared with cities that tend to obtain high-quality resources, market segmentation between cities severely restricts the cross-regional flow of factor resources, which will cause problems such as blind investment by local governments, speed of comparison, isomorphism of industries, and resource competition, resulting in inter-regional problems. The lack of overall planning and coordination leads to a loss of economic efficiency, which is not conducive to the development of urbanization. The development of China’s urbanization has moved from traditional urbanization based on urbanization rate to new-type urbanization based on urbanization efficiency, and new-type urbanization pursues green development and high-quality development. This paper explains the implementation mechanism of China’s urbanization efficiency improvement from the two dimensions of urban administrative hierarchy and market segmentation, and uses empirical tests with China’s urban data (excluding Hong Kong, Macau and Taiwan) and dynamic spatial panel model from 2003 to 2017. For the evaluation of urbanization efficiency, the modified Super-SBM is used for calculation to consider the impact of environmental factors. This is not only a more scientific and comprehensive evaluation of the efficiency of China’s urbanization, but also a high-quality development concept of green, low-carbon, intensive and efficient urbanization in China. Since changes in urbanization efficiency involve the spatial transfer and allocation of various element resources, this paper intends to use a dynamic spatial panel model to empirically study the effects of urban administrative hierarchy and market segmentation on urbanization efficiency, and conduct a series of robustness and heterogeneity tests. The conclusion of the study shows that the hierarchy of urban administration and the degree of market segmentation are the two major institutional barriers that impede the improvement of China’s urbanization efficiency, and thus fall into the development dilemma of ‘high-hierarchy, high-segmentation and low-efficiency’. The mechanism inspection found that the reason is that high-hierarchy cities use administrative advantages to sacrifice ecological urbanization and excessively pursue population urbanization, economic urbanization, and land urbanization. This is due to differences in household registration systems, local protection and environmental governance. Further heterogeneity tests found that the establishment of high-hierarchy cities in the eastern region, as well as high-intensity environmental constraints, more advanced infrastructure, more efficient public services, and a more open investment environment can greatly alleviate the inhibition effect of urban administrative hierarchy to urbanization efficiency.
Carrying out the coordinated relationship between urbanization and water resources is of great significance to the ecological protection and high-quality development of the basin. The changing trends of the comprehensive level of the urbanization and water resources from 2010 to 2019 was analyzed in this study using comprehensive evaluation method by constructing two index systems for the urbanization development and the water resources in the Fenhe River Basin. On this basis, the coupling coordination model was constructed to analyze the coupling coordination relationship between urbanization and water resources in the Fenhe River Basin. The results show that the comprehensive urbanization index shows an overall upward trend, and the importance of the urbanization subsystem appears: economic urbanization > social urbanization > spatial urbanization > population urbanization; the comprehensive index of water resources shows a fluctuating upward trend, and the importance of the water resources subsystem appears: water resource utilization > water resource level > water resource protection. The water resources environment is continuously optimized, with a short-term decline in 2013 for the influence of water resource and water consumption and other factors. From a temporal perspective, the coupling coordination degree between urbanization and water resources has been continuously improved from 2010 to 2019 in the Fenhe River Basin. From a spatial perspective, the coupling and coordination degree of urbanization and water resources of the 6 cities in the Fenhe river basin has been continuously improved. Meanwhile, there are regional differences among them: Luliang, Taiyuan and Xinzhou are in good coordination stage; Linfen and Yuncheng are at a barely coordinated stage; and Jinzhong is on the verge of imbalance. This research can provide a theoretical basis and reference for the future coordinated development of water resources and spatial urbanization of the Fenhe River and adjacent basins.
Children’s recreation is not only related to the construction of child-friendly cities and the realization of children’s civil rights but also an important segment of the leisure industry. This study evaluates the supply and demand of recreation for children aged 3-12 years old in China from different perspectives of publicity and commerciality. The children’s recreation supply index is divided into several secondary supply indexes according to the properties, prices, and types of recreation supply. It combines geographic data, statistical data, and tourist-generated data, and uses the natural breakpoint method and spatial difference analysis to present municipal-spatial differentiation characteristics. The study also uses stepwise regression and geographically weighted regression to identify the factors that influence the supply of children’s recreation in China’s cities. The main conclusions are as follows: 1) There is a distinct spatial heterogeneity and polarization in the supply and demand of children’s recreation in China. Both the children’s recreational demand and supply take the Hu Huanyong Line as the watershed, showing an overall trend of high in the southeast and low in the northwest. The demand is centered on municipalities and provincial capitals, and the supply is centered on municipalities and tourist cities. 2) The balance of supply and demand shows that the central inland hinterland is relatively scarce, the western and eastern coastal areas are abundant, and the provincial capitals of the east of the Hu Huanyong line are relatively scarce except for municipalities and tourist cities. 3) The provincial capitals present the phenomenon of spatial polarization and differentiation, with the characteristics of high demand and high supply, as well as significant agglomeration and siphon effects. 4) The factors influenced children’s recreation supply in China from high to low, are GDP, per capita disposable income of urban residents, the number of high-level scenic spots, the proportion of tertiary industries, tourist arrivals, and the rate of urbanization. This study reveals the current macro status of the supply and demand of recreation of children in China. The evaluation dimensions and methods have innovative value for the study of recreational space. The results of spatial differentiation and influencing factors analysis have implications for the construction of children-friendly cities.
Accurate identification of urban built-up area boundary is of great significance to implement urban planning and construction scientifically and promote sustainable development of urban and rural areas. From the definition, urban built-up area is the surface space with dense construction land and complete municipal public facilities and public facilities. However, existing urban built-up area extraction methods only consider one feature of built-up areas. Based on the concept of urban built-up area, this article takes the contiguity of construction land and the configuration of public service facilities into account, proposing a method of urban built-up area extraction based on POI kernel density and impervious surface area index. In this method, impervious surface area index and POI kernel density of municipal utilities and public facilities are used as main data sources, and urban built-up area can be extracted accurately by constructing POI&ISA index and selecting optimal threshold. Taking Wuhan urban development area as an example, compared with the results of built-up area extraction based on POI method, it is proved that the method based on POI&ISA index has higher extraction accuracy. This method can make up for the deficiency of single POI data source in urban built-up area extraction, improve the representation ability of public facilities through POI data primary selection and appropriate selection of bandwidth, and obtain better extraction effect of urban built-up area in local area. Moreover, the data required by this method has the characteristics of fast updating, which can fully guarantee the timeliness of extraction of built-up areas. In the future, the application and improvement research of POI&ISA index should be further carried out to enrich the theory and method of urban built-up area extraction.
Linfen Basin in the middle and lower reaches of Fenhe River was selected as the study area. Based on the monitoring data of groundwater depth for many years, the temporal and spatial variation of groundwater depth and its control factors in this area were systematically analyzed. The results showed that: 1) The groundwater depth in the study area showed an increasing trend from 2007 to 2018. The difference of groundwater depth in different regions is obvious, showing a trend of high in the east and low in the west. Yaodu and Xiangfen have obvious overexploitation. 2) The fluctuation of groundwater depth is obvious after 2010, and the variation amplitude of each district is significantly higher than that before 2010. 3) The groundwater depth showed a trend of gradual increase from north to south at the annual scale, and the variation of groundwater depth in spring was the largest and mainly with the decrease of groundwater depth. Spatially, the shallow groundwater depth is mainly concentrated in Huozhou, Hongtong, southern Quwo and northern Yicheng, and the deepening area is mainly concentrated in Xiangfen, southwest Yaodu and northwest Houma. 4) The change of groundwater depth in the study area is more sensitive to evaporation, less sensitive to rainfall and rural water use, and the population has a greater contribution to the change of groundwater depth.
Extreme high temperature is extremely destructive and influential, and characterizing its change over time and space can provide help to guide future efforts to mitigate impacts of climate change. Based on the daily scale observation data of 2419 meteorological stations in China, the trend analysis, the time-lapse analysis and Mann Kendall mutation test were used to study the change characteristics of extreme high temperature with time in China in the past 40 years. The trend change and distribution pattern (direction feature) of the extreme high temperature distribution pattern in the corresponding years were explored by using Moran index and standard deviation ellipse respectively. The results show that: 1) The number of summer days, hot night days, warm night days and warm days in China showed a significant upward trend. The four indexes were less in the 1980s and 1990s, and gradually increased after 2000 and commonly changed significantly circa 2000;2) The spatial autocorrelation of the four extreme temperature indices was mainly high-high and low-low. The summer days and hot night days had strong aggregation, while the spatial aggregation of warm night days and warm days first increased and then decreased in past 40 years, and the spatial distribution pattern of warm night days and warm days changed from high-high surrounding low-low to low-low surrounding high-high; 3) The most obvious points of directional distribution of change trend of Summer days, warm days and hot night days are in the north. The stations of summer days and warm days showed the southeast-northwest distribution pattern, while the stations of hot night days showed the East-West distribution pattern. The stations with the largest change trend of summer days are East-West distribution pattern, while the stations with the largest change trend of hot night days, warm night days and warm days are north-south distribution pattern. The most significant changes of the four extreme temperature indices are in southern China. The change rates of summer days and warm days in the border areas of Gansu, Sichuan, Shaanxi and Chongqing in past 40 years are higher than those in other regions of China. The directional distribution of change trend of warm night days in Zhejiang and Fujian is the most obvious, and the change trend is higher than that in other areas of China. Our results provide meaningful information for a deeper understanding of the spatiotemporal variations in temperature extremes across the mainland China.
Evapotranspiration is one of the critical processes in the surface water cycle. Assessment of evapotranspiration and its characterization is essential for understanding the regional water cycle processes. We used the Penman-Monteith (P-M) equation and the two-crop coefficient method to calculate the actual evapotranspiration in the Minjiang River Basin. Meanwhile, used P-M results to evaluate the applicability of the GLDAS-Noah actual evapotranspiration product in the Minjiang River Basin. Then, the GLDAS-Noah actual evapotranspiration product is used to analyze spatial and temporal patterns of actual evapotranspiration in the Minjiang River Basin from 2000 to 2019. The results show that: 1) The GLDAS-Noah actual evapotranspiration product has good applicability (R2 > 0.9 and NSE > 0.8) in the Minjiang River Basin; 2) The actual evapotranspiration in the Minjiang River Basin has been increasing since 2000 (3.86 mm/a, P = 0.0086), and there are significant seasonal differences, showing that the increase rate in winter and spring is more significant than that in summer and autumn; 3) The increase in winter and spring evapotranspiration in the Minjiang River Basin was closely related to air temperature. There is a weak positive correlation between winter evapotranspiration and winter air temperature (R = 0.27) and an increase in spring evapotranspiration closely related to spring warming (R = 0.79). The results of the study help to deepen the understanding of the evapotranspiration characteristics of the Minjiang River Basin in the context of global warming and provide an experimental basis for assessing the eco-hydrological processes in the Minjiang River Basin based on the GLDAS-Noah model products.
