Promoting the rural-urban Hukou transfer of internal migrants is a crucial task in China′s New-Type Urbanization scheme. Along with the lowering threshold of acquiring a local Hukou in most cities and the changing patterns of internal migration, the decision of rural-urban Hukou transfer has no longer depended merely on the institutional gap between urban and rural areas, but also reflected the growing and diversifying needs of migrants. This article developed a novel analytical framework for understanding the rural-urban Hukou transfer intention from a family strategy perspective and by emphasizing the crucial role played by rural rights. Based on the 2017 China Migrants Dynamic Survey (CMDS) data, this article found that the basic unit of the decision on rural-urban Hukou transfer is the entire family of migrants; the decision mechanism is a trade-off between benefits attached to rural and urban Hukou of migrant family members; and the main goal is to maximize the total benefits in the hometown and destination, instead of realizing the stable settlement and reunion in the host city of the entire family. The conclusions are as follows. (1) For a couple, one′s possession of urban Hukou will decrease the spouse′s likelihood of holding a rural-urban Hukou transfer intention, which can be termed as the "benefit-ceiling effect" because the potential gain of the spouse′s Hukou transfer is much less for these families than their benefit loss by giving up the rural Hukou and the adherent rural rights. Hence, most migrant families have chosen an "urban-rural separation" Hukou strategy to maximize their benefits from two sides. Eventually, the rural-urban Hukou transfer of China′s internal migrants is characterized by "anti-familization". (2) The rural-urban Hukou transfer intention of migrants has also been hindered by the "retention effect" of threefold rural rights. Specifically, the rights of farmland contracting, housing land occupation, and collective benefits sharing in their rural homeland have decreased the tendency of rural-urban Hukou transfer. (3) Rural rights have negative moderating effects on the familization of migrants′ rural-urban Hukou transfer, which have overshadowed the "family reunion effect" and resulted in an overall trend of anti-familization. To be specific, one′s intention to rural-urban Hukou transfer will be enhanced by the spouse′s local Hukou, which can be described as the "family reunion effect". Considering the moderating effects of rural rights, however, more than half of migrant families would like to maintain the separation strategy of the Hukou status among family members.
Research on high-resolution population evolution is of great reference for understanding, simulating, and managing the human-nature interrelationship. Town-level demographic data is the highest-resolution data publicly released by the National Bureau of Statistics of China. Therefore, it is of great significance to collect the population data of China at town level, and to carry out research on the spatiotemporal evolution and its influencing factors of Chinese population at town level. In this study, we established a spatial database of Chinese population at town level in 2010 and 2015, and then revealed its spatial and temporal pattern and influencing factors by Geographic Information System (GIS) analytical methods and Geodetector model. The results showed that: (1) In 2015, the average population of towns was 29,500, and the average population density was 374 persons/km2. Furthermore, there existed large spatial heterogeneity in China, the number of townships with a population of more than 10,000 is 781, mainly in the Yangtze River Delta and the Pearl River Delta, while the number of townships with a population of less than 5,000 is 2,498, mainly in the Qinghai-Tibet Plateau and Inner Mongolia. (2) The distribution of population and land area of townships was greatly uneven. There were 19,403 (60.81%) townships with a population density of more than 150 persons/km2, and their total population and land area accounted for 81.76% and 20.27%, respectively, which was approximately in line with “Pareto's Law”. (3) From 2010 to 2015, more than 70% towns’ population increased, by contrast, the population of more than 9,000 towns decreased, of which more than 1,600 towns experienced a population loss of more than 20%, and most of them were located in the border areas of Northeast China, Inner Mongolia and Yunnan. (4) The population distribution is comprehensively affected by physical geography (e.g., relief degree of land surface, negative effect) and socio-economic factors (e.g., night time light index and road density, positive effect), and its mechanism has obvious spatial stratified heterogeneity in different regions. This study argues that the rapid population growth or loss brings great challenges for harmonizing human-environment relationships, such as territory spatial planning, rural revitalization and national border security.
There is a growing recognition that migration is a repetitive event, involving initial movements outside the hometown, and subsequent return or onward movements, which has a profound influence on the development of origins and destinations. This paper analyzes personal and regional reasons for migrants′ behavior of settling down, returning home and moving on. Based on data from the 2016 China Labor-force Dynamics Survey, and by using event history analysis, we investigate how life events, the characteristics of origins and destinations, and the multi-distance of migration affect migrants′ decision-making. The findings show that the probability of return and onward move is the highest in the first three years after initial movement, and then declines rapidly. The spatial differentiation of migrants' behavior is obvious, which is reflected in the following facts: First, inter-provincial migrants are more inclined to move on than intra-provincial ones. Second, the larger the city, the less likely that migrants settle down. Personal and regional factors play significant roles in determining migrants′ action. Migrants who have married are more likely to remain in the recent destination than those who are not married. Life events can induce the reselection of residence. Migrants will leave the current city when their studies come to an end, and are pretend to return home to acquire support from parents if they lose their jobs. The effect of origins and destinations′economic development as well as their distance is also notable. When the economic growth of the destinations slows down and the development of the origins improves, the migrants are more inclined to return home. The propensity for return is also high provided that the origins and destinations are located in different cultural districts. Additionally, the effect of regional features varies from inter- to intra-provincial migrants and from well- to less-educated migrants. The results above are instructive. First, the intentions and behaviors of the migrants are inconsistent, and the difference between the two is worth studying. Second, the timing of decision-making has a non-negligible impact on the behavior of migrants. The dual perspectives of individual life course and social environment changes in studying population migration need more attention. Last but not least, the dichotomy, return and not return, stay and leave, for instance, conceals the difference between settlement, return and onward movement, which should be included in the same framework for comparative analysis.
Identifying the multi-scale trade-offs and their influencing factors among ecosystem services (ESs) is crucial for guiding management strategies and promoting sustainable development. However, the scale response characteristics and mechanisms are still very unclear due to the lack of scientific scale division method. This paper used empirical statistics and biophysical models to assess four typical ESs, including two supporting services (soil conservation and habitat quality), one regulating service (water conservation) and one cultural service (natural recreation). The characteristic scales of the trade-offs between cultural and other three types of ESs were obtained based on the continuous wavelet transform. By combining the ecological feature scales with the administrative management scales, the optimal scale sequence for the trade-off study was finally constructed. Then we applied correlation analysis and geographical detector to quantitatively identify the influencing factors of ES trade-off at each scale and compare the difference characteristics of dominant factors between different scales. The results showed that: (1) The characteristic scales of ES trade-off were prominent along the six transects, and 2000-11500 m was the optimal scale sequence range for the study on trade-off. (2) There was an identified trade-off between natural recreation and soil conservation, and natural recreation showed stable synergistic relationships with water conservation and habitat quality. Most correlations of the three paired ESs enhanced as the scale increased, and the strongest synergies or the weakest trade-offs were found at the county-level administrative scale, making it the best scale unit for making and implementing ecosystem management decisions. (3) Vegetation coverage was the most important and relatively stable driving force throughout the whole scale sequence, while the influences of other factors mutated at the township level. It was proved that the topography was the major influencing factor on smaller scales, and the landscape metrics and climatic factors gradually became involved in controlling ES trade-offs with the increase of scale. In conclusion, this study optimizes the traditional unit division method by introducing wavelet transform, which provides a scientific and powerful premise for a comprehensive understanding of the multi-scale trade-offs and influencing factors among ESs. Our results will provide a reference for regulating various driving factors to make multi-level management decisions in the Pearl River Delta region.
The loess hilly and gully region is an ecologically fragile and economically underdeveloped area. The human well-being of local farmers depends largely on their access to various ecosystem services. Research on the impact of ecosystem services on human well-being in this area has important theoretical and practical significance for analyzing the social contribution of local ecosystems and effective poverty reduction. The accessibility of ecosystem services was assessed on the basis of integrating objective well-being and subjective well-being taking Mizhi County, Shaanxi Province in the loess hilly and gully region as a study area. The impact of ecosystem services on human well-being was quantitatively analyzed by structural equation model (SEM). At the same time, the group differences of impact were explored based on the farmers classification. The results were as follows: (1) ecosystem services had a significant positive impact on objective well-being and subjective well-being, and had an indirect impact on subjective well-being through objective well-being. The farmers’ socioeconomic characteristics had significant direct effects on ecosystem services and objective well-being, but did not have significant direct effects on subjective well-being. Firewood, crops, livestock were key ecosystem services types. Soil conservation was the main regulating service, while cultural services had a relatively weak impact on human well-being. (2) There were group differences in the impact of ecosystem services on human well-being. Ecosystem services accessibility of pure agricultural farmers and part-time farmers had significant direct effects on objective well-being, but not for non-agricultural farmers. The direct effects of ecosystem services of pure agricultural farmers and part-time farmers on subjective well-being were significantly greater than those of non-agricultural farmers, and the indirect effects of ecosystem services on subjective well-being of non-agricultural farmers were not significant. The objective well-being of non-agricultural farmers had a much greater impact on subjective well-being compared with pure-agricultural and part-time farmers. (3) There were group differences in the contribution of ecosystem services to human well-being and the ecosystem services combinations, that is, the difference in the impact of ecosystem services of the three groups on human well-being was not only reflected in the types and extent of ecosystem services, but also in the differences in the combination of ecosystem services.
Scientific description and simulation of the spatio-temporal pattern of land use conflicts are the basis for a better understanding of regional land use structure and organization, and for seeking the coordination of man-land relationship. Firstly, this study uses the landscape pattern index to construct a land use conflict strength model. Besides, with the help of GIS and other methods, this study analyzes the spatio-temporal evolution characteristics of land use conflicts in the Yangtze River Delta urban agglomeration from 1980 to 2020. Finally, by combing the patch-generating land use simulation and multi-objective programming models, this study simulates the land use conflict pattern in 2035. The results show that: (1) Influenced by factors such as terrain and population distribution, the land use conflict in the study area shows a distribution pattern of high in the north and low in the south. Under the influence of factors such as rapid urbanization and urban sprawl, the degree of land use conflicts has intensified year by year. High-value areas of land use conflict are mainly distributed in densely populated, economically developed and easily accessible areas, while low-value areas are mostly concentrated in rugged terrain and sparsely populated areas. (2) Affected by population migration and the development stage of urbanization, land use conflicts in this urban agglomeration were mainly reflected in the rural space from 1980 to 2000, and in the urban space from 2000 to 2020. (3) The cultivated land of the urban agglomeration has a vast area, fertile soil, flat and open terrain, and suitable climatic and hydrological conditions, which brings huge economic and ecological values. Therefore, cultivated land is the core area that various stakeholders compete for, as well as a "key zone" to alleviate land use conflicts. (4) The sustainable development scenario takes the land demand for both economic development and ecological protection into account, which can not only meet the economic construction needs of the Yangtze River Delta urban agglomeration, but also effectively alleviate land use conflicts.
In order to clarify the mechanism of soil properties affecting erosion form of Loess Plateau, this study uses indoor simulated rainfall tests, and the typical rainfall intensity, to analyze the slope erosion forms, morphological characteristics, runoff and sediment yield processes and corresponding changes of runoff velocity of two types of loess under different slope conditions. The results show that the runoff of Suide soil is obviously higher than that of Ansai soil. On 10º, 15º and 20º slopes, the average runoff rates of Suide soil are 51.1%, 55.5% and 63.0% higher than those of Ansai soil, respectively. In terms of the form of erosion, Suide soil is more likely to form rill, and the average sediment concentration and yield of Suide soil are 1.14-3.59 times and 2.50-8.48 times of Ansai soil, respectively. During the sheet erosion stage, Ansai soil has a higher sediment concentration, which is 1.24-1.73 times that of Suide soil. Therefore, the two types of soil have the same change law of sediment concentration and sediment yield, and they both increase rapidly to a maximum value, and then gradually decrease to a relatively stable state. Sheet erosion can be divided into two erosion stages, the initial stage controlled by a transport-limited condition and the subsequent stage controlled by erosion-limited condition. During the rill erosion stage, the development of rill is dominated by headcut advance and its frequent collapse. This erosion form not only affects the characteristics of rill morphology, but also leads to a rapid increase in both the sediment concentration and sediment yield, the average sediment concentration is 3.25-4.34 times of that in sheet erosion stage, and there is an obvious sediment deposition belt below the rill mouth. This indicates that the transport capacity of rill flow is much higher than that of sheet flow, and rill erosion is mainly controlled by a transport-limited condition. The runoff velocity of both types of soil increases as the distance from the top of the slope increases, and the velocity after the runoff stabilizes is higher than that before the runoff stabilizes. Overall, the average flow velocities of Ansai soil and Suide soil on the upslope and after runoff stabilization are 1.75 times, 1.29 times and 1.4 times, 1.25 times of that on the downslope and before runoff stabilization, respectively. At the same time, the interaction between the rill erosion or the erosion intensity and the micro-morphology could also affect the runoff velocity.
The main driving forces of China’s economic growth have gradually shifted from production factors and investments to innovations since the 2010s. The high-tech industry is knowledge- and technology-intensive and is one of the key intermediaries in regional innovation systems. Therefore, the development of high-tech industry or high-tech enterprises contributes to regional development, especially in the context of the “new normal” of China’s economy. However, researchers have paid little attention to factors affecting the distribution of high-tech enterprises with spatially varying effects. With the help of the data of 215,791 high-tech enterprises and multiscale geographically weighted regression, this paper described the spatial distribution of China’s high-tech enterprises in 2019 and explored the spatial and scale variation of its determinants. The following conclusions were drawn. First, in 2019, the spatial distribution of China’s high-tech enterprises showed a high concentration, with Beijing, Shanghai, Guangzhou and Shenzhen as the primary cores, and Chengdu-Chongqing region and several regional centers as the secondary cores. Second, the attributes of high-tech enterprises, the capabilities of urban knowledge creation and technological innovation, innovation environment and extra-regional linkages are the main factors affecting the distribution of high-tech enterprises. Third, the determinants showed spatially varying effects. Specifically, the positive impacts of new companies, college students and the Internet presented an “East-West” spatial differentiation pattern; the positive impacts of the number of patent applications, high-tech zones and amenities showed a “South-North” spatial differentiation pattern. The positive effects of high-speed rail presented a “Southeast-Northwest” spatial differentiation pattern; R&D expenditure is a strong driver in Northeast China; marketization has the most significant impact on the Beijing-Tianjin-Hebei and Pearl River Delta urban agglomerations. Fourth, the determinants have different working scales, and the variables indirectly related to the profits of high-tech enterprises that need a transformation process (e.g., R&D investment, extra-regional linkages) have less significant spatial variation than other factors (e.g., high-tech zones, the number of college students, the number of patent applications). Finally, justified on territorial equity criteria, this research provided several suggestions for improving spatially unbalanced innovation (high-tech enterprises), helping developing regions jump faster (develop high-tech industry). Current findings broaden our understanding of the associations of geography and scale with high-tech industry in an emerging large-scale economy.
Cross-border mergers and acquisitions of high-tech enterprises (technological M&As), an important way for enterprises to acquire international advanced knowledge, have been rising worldwide in recent years. At the same time, the Belt and Road countries and regions have also attracted several large-scale technological M&As, which is of great significance for further promotion of the Belt and Road Initiative in the field of investment and technical cooperation. However, we remain almost clueless about this new phenomenon, especially in developing or less developed countries/regions along the Belt and Road, which show quite different characteristics and mechanisms in technological M&A activities from the developed ones. Therefore, based on the data for the cross-border M&As of targeting high-tech enterprises from 1998 to 2017, this paper explores the evolution characteristics and its mechanism of technological M&A network along the Belt and Road, via complex network analysis, the GIS method, and the zero-inflated negative binomial model. Our empirical results show that: (1) The scale, scope, and density of technological M&A network have increased significantly, but the level of networking is relatively low. Therefore, the number of countries/regions, connection paths, and connection density in the network need to be further improved. (2) Although the industrial structure of technological M&A network is dominated by the information and communication technology industry, there is a pluralistic trend that enterprises from non-high-tech industries are also getting increasingly involved in technological M&A network. The number of companies that have acquired financial industries in Hong Kong of China and Singapore has increased significantly. (3) The spatial distribution of technological M&A network is extremely uneven. China, India, and Southeast Asia are found to be the rapid growth areas in the launch and receive for network connection, while the first-mover advantage of Central and Eastern Europe in the network became less obvious; Central Asia and the Caspian Sea surrounding areas do not have the ability to launch a network connection. (4) The evolution of technological M&A network is to varying degrees influenced by proximity indicators between countries/regions, which are related to geographical, historical and religious factors. However, in terms of the indicator attributes for each country/region, economic market size and regional stability level for technological M&A only affect receiving the network connection, while the technology level only affects launching from 2013 to 2017.
High-speed railway is an important carrier of China's social and economic development. Under the background of extremely close social and economic ties, studying the resilience of high-speed rail urban network is of great significance to guaranteeing national social and economic development. This paper constructed a high-speed rail urban network based on the traffic data between China's high-speed rail cities from the perspective of vulnerability, studied the network resilience of China's high-speed rail cities, and discussed the network resilience and urban responses of Wuhan and Hubei in lockdown under the background of the COVID-19 pandemic. The main conclusions are as follows: (1) The development level of China's high-speed rail urban network needs to be raised. Regional differences and hierarchies are developed significantly in the network. (2) The core city in the network has a prominent position, which has strong network control capability and obvious correlation effect. The network has strong adaptability and recovery ability, but the network resilience is significantly affected by key nodes. (3) Intentional attacks could significantly reduce the urban network resilience, but the core network can still maintain a high operating efficiency without the core network being severely hit. (5) The core network retains the main characteristics of China's high-speed rail urban network with the pattern of “high level in the east, but low level in the west”. The Beijing-Guangzhou and Beijing-Shanghai high-speed railways are the skeleton of the core network with the most frequent communication, while the western region seems to be ignored in the core network. (5) The lockdown of Wuhan and Hubei has a small impact on the resilience of overall high-speed rail urban network, but has obvious influence on city nodes. The network resilience is significantly affected by administrative divisions, transportation lines and distance. With the adjustment of the core-periphery structure of the urban network, cities will enhance their degree of centrality to compensate for the lack of core status of failed areas. In the future, the planning and construction of resilient cities should be promoted by strengthening the prevention of urban network risks and optimizing the layout of high-speed rail network structure to enhance the resilience of urban network and promote high-quality social and economic development.
Urban agglomerations are important carriers to promote the regional socio-economic development and participate in the international competition in the advanced stage of urbanization. And the high traffic accessibility is essential for the high-quality development of urban agglomerations. According to the 2h access goal of urban agglomeration proposed in the Outline of Building a Country with a Strong Transportation Network, taking three national urban agglomerations in the Yangtze River Economic Belt as the study area, this paper employs the weighted average travel time as the measurement index and constructs the field model and the gravity model to comparatively analyze the pattern characteristics of 2h travel circle of all cities and central cities in the three urban agglomerations. The results show that: firstly, the weighted average travel time of all the cities in the three urban agglomerations shows the “circle-type” spatial pattern that continuously expands from low (the center) to high (the periphery). Specifically, the 2h travel corridors exhibits the “>” pattern in Yangtze River Delta urban agglomeration and displays the “cross” pattern in Chengdu-Chongqing urban agglomeration; but Yangtze River Middle Reaches urban agglomeration has not formed 2h travel corridors. Secondly, the spatial distribution of the 2h travel circle of the central cities is significantly affected by the geographical location: the closer to the geometric center of the urban agglomeration, the larger the coverage of 2h travel circle. Moreover, the spatial distribution of the hinterland is affected by the comprehensive scale of the central city. And there are large differences in the spatial distribution of the 2h travel circle and the hinterland among the three urban agglomerations. Thirdly, there are significant differences in the connectivity of 2h travel circle among different urban agglomerations, which shows the pattern of multiple circle superposition and economic connection. The Yangtze River Delta urban agglomeration has initially formed the hierarchical network structure of central cities, while the Yangtze River Middle Reaches and Chengdu-Chongqing urban agglomerations stay at the development stage of connection axis. Fourthly, the spatial arrangement of the transport infrastructure has significant influence on the connectivity of 2h travel circle of the central cities. The high-density expressway network plays an important role in improving the connectivity of 2h travel circle in central cities at the scale of urban agglomeration. From the viewpoint of the structure of connectivity, urban agglomerations can be classified into three types: polycentric-network type, polycentric-cluster type and bicentric-radial type.
Under the background of new urbanization, the human settlement environment in Chinese traditional villages is facing a rigorous crisis of the human-land relationship, and the organic renewal of it is particularly important. Based on the scientific connotation of the organic renewal and the evolution characteristics of the human settlement environment in Chinese traditional villages, this paper analyzed the theoretical cognition of the organic renewal of the human settlement environment in traditional villages, and constructed the path mechanism of the organic renewal of the human settlement environment in traditional villages on this basis. The results show that: (1) By summarizing the problems faced by the human settlement environment in traditional villages, the dilemma is classified as material space, cultural space and social space, and the theoretical cognition of the organic renewal is proposed with living-production-ecological space as the spatial carrier, the landscape gene as the cultural core, and the social field as the basic context. (2) Focusing on the renewal and optimization of material space, cultural space and social space, the three-dimensional path mechanism of "material-culture-society" for the organic renewal of the human settlement environment in traditional villages is constructed, including the renewal of the material space: the optimization of dominant functions and the reshaping of living-production-ecological space; the renewal of the cultural space: the repair of recessive genes and the repair of dominant genes; the renewal of the social space: the darning of relationship networks and the reconstruction of social order. In order to realize the sustainable development of the human settlement environment in traditional villages, the theoretical cognition and practical path of the organic renewal are discussed in depth, and have been established as a "multi-dimensional optimization, and multi-objective overall planning" mechanism, to provide scientific and practical reference for the organic renewal of the human settlement environment in Chinese traditional villages.
Crime location choice has been a central theme of crime geography research. However, the current research reveals little about the spatial differences among different age groups of criminals when they choose crime locations. Using kernel density estimation and discrete spatial choice models in ZG City, China, this study aims to explore the spatial variation in crime location choices of street robbers at different ages. We also examine the different influences of activity nodes, supervision role, and social disorganization on crime location choice. The results demonstrate that there are significant spatial differences in crime location choices by street robbers at different ages. Juvenile robbers tend to commit crimes in labor-intensive industrial clusters and primary and secondary school areas, young adult robbers tend to commit crimes only in labor-intensive industrial clusters, and adult robbers prefer urban areas with transportation hubs. Additionally, this study demonstrates that age-related activity nodes, the supervision role of the ambient population, and the proportion of youngsters are the main factors for such spatial differences. Some conclusions can be drawn as follows. (1) Cybercafés have impact on crime location choices of juvenile and young adult robbers, while transportation hubs affect those of young adult and adult robbers, and bars and schools influence all the three age groups, but with a marginal age decay effect. (2) The supervision role exerted by the ambient population is greater for young adult and adult robbers compared with juvenile robbers. (3) Young adult robbers are more likely to target communities with more youngsters but juvenile and adult robbers are not. (4) Journey to crime has a significant negative effect on target choices, especially on juvenile robbers. In addition, these findings have great informative value for crime prevention and social governance. For example, (i) in labor-intensive industrial clusters where juvenile robbers frequently commit crimes, we can regulate the number of age-related activity nodes such as cybercafés and bars; (ii) in transportation hubs and their surrounding communities where adult robbers commit crimes intensively, we can encourage the persistence of the ambient population to persist and play a better supervision role; (iii) in communities predominated by youth population, we can survey delinquent juveniles to enhance the precise guidance and support.
It is a controversial scientific problem that what factors affect and restrict the characteristics and sources of water chemistry at a watershed scale. To get the answer, it is necessary to integrate the natural water bodies in different geographical units and specific environments. In this paper, three hydrological systems (Yily, Junggar and Erlqis) in Northern Xinjiang were selected to carry out hydrogeochemical research, in order to understand the hydrochemical characteristics, causes and influencing factors of typical drainage systems in the arid environment of the Central Asian Orogenic Belt (CAOB). Based on the natural water samples we collected the three drainage systems in Northern Xinjiang, and used their hydrochemical data of the subsequent analysis, together with the hydrogeochemical data newly collected in this study from the latest Chinese and Western scientific literatures focused on the study area and its surroundings as well as other typical catchments in the world, to made comprehensive intra- and inter-regional comparisons between the study area and other middle-latitude regions and typical climate zones. The results show that the total dissolved solid concentration (TDS) of rivers in Northern Xinjiang water system is generally higher than that of rivers in monsoonal and humid regions of China, and also higher than the world average level. The main cation and anion of the water body are dominated by Ca2+ and HCO3-, respectively. The relative concentration of major ions in the study area is similar to that of rivers in the eastern monsoon region of China, and similar to most of rivers dominated by carbonate weathering in the world. Rock weathering plays a dominant role in most parts of Northern Xinjiang in terms of hydrochemical genesis. Further quantitative result shows the order of solute contribution from different sources to natural water: evaporite dissolution > carbonate weathering > silicate weathering > atmospheric precipitation, which fully proves the dominant position of evaporite dissolution and carbonate weathering. Compared with the weathering situation between silicate and carbonate, the influence of silicate is greater in the middle and low terrain areas of Northern Xinjiang drainage systems, while the influence of carbonate is greater in mountainous areas with higher elevations. Regional precipitation, hydrothermal combination, runoff and lithology all have important impacts on the hydrochemistry of drainage systems of the study area, but the relationship with temperature is not obvious, and the relationship with physical erosion process of the basins is not clear, which requires further research.
Reducing chemical fertilizer and increasing biofertilizer are important ways to achieve green agricultural development in China. This paper used production function to investigate the evolution of cotton chemical fertilizer application intensity and its effect on cotton yield per unit area in Xinjiang from 2000 to 2020. Based on the survey data from 2015 to 2020, an evaluation index system was constructed using entropy weight method to evaluate the comprehensive benefits of two types of fertilizers. Furthermore, the feasibility and realization mechanism of using biofertilizer to replace chemical fertilizer were discussed. The results showed that: (1) The total amount of chemical fertilizer per unit area of cotton in Xinjiang increased continuously, and it was higher than the level in most provinces. Since 2016, the amount of cotton fertilizer in Xinjiang tended to slow down and stabilize, and the amount of cotton fertilizer fluctuated around 585 kg N/hm2. (2) From 2000 to 2010, the increase of fertilizer application per unit area positively promoted the increase cotton yield per unit area. While the contribution rate of increasing fertilizer application per unit area to the increase of cotton yield per unit area was -21.29% from 2010 to 2020, indicating that a continuous increase of chemical fertilizer had a negative effect on the increase of cotton yield per unit area. (3) The ecological benefits of the biofertilizer were more prominent, but the economic benefits of the biofertilizer fertilization area were slightly lower than that of the chemical fertilizer area, and the comprehensive benefits of the two fertilizers tended to narrow down with the increase of use years. The average yield per unit area of cotton in the biofertilizer group was 3%-8% lower than that in the chemical fertilizer group, but the incidence of verticillium wilt was significantly reduced in the biofertilizer group and the average decrease in different cotton planting areas was 27.75%-58.20%, soil organic matter content increased by 14.59%-28.54%, and soil microbial quantity increased significantly. The fertilizer cost per acre of biofertilizer was 14%-19% higher than that of chemical fertilizer. The characteristics of biofertilizer require some incentive or ecological compensation policies to guide and raise farmers' environmental awareness at the beginning of the promotion of biofertilizer. It is feasible to reduce the amount of agricultural chemical fertilizer and gradually replace agricultural chemical fertilizer with biofertilizer.
MODIS C6, VIIRS V1 and VIIRS J1 are the three standard active fire products provided by the Fire Information Resource Management System (FIRMS), which jointly record active fire detections for the first time in 2020. In view of the differences in satellite overpass time, spatial resolution, and detection algorithms, a comparison of the consistency and discrepancy of MODIS and VIIRS active fires is important for understanding their usability. Here, the consistency and discrepancy were quantitatively cross-compared via examining the frequency and intensity characteristics of fire occurrence and their spatial differences in Mainland Southeast Asia (MSEA) at hourly, diurnal, monthly, and seasonal scales through fishnet analysis (1 km). The results show that: (1) The highest consistency of occurrence frequency of MSEA’s active fire among the three products is seen at the monthly level, followed by those at the daily and hourly ones. MODIS- or VIIRS-derived active fires occurred and re-occurred in a total of 37.23% fishnet cells within MSEA, or the “fire-affected grids(FAGs)” with at least once. The proportion of VIIRS FAGs is three times more than that of MODIS, and J1 slightly outnumbers V1. The consistency between VIIRS V1 and J1 is the highest, while that of VIIRS J1/MODIS C6 is the lowest. (2) FAGs proportion, occurrence frequency and intensity of these three products during the dry season are significantly higher than those during the rainy season, particularly the spatial distribution of fire occurrence intensity between VIIRS V1 and J1. The fire occurrence and intensity of VIIRS V1 ranks the first in the dry season, while J1 performs the best in the rainy season. (3) The proportion, occurrence frequency and intensity of these products in the daytime are higher than those in the nighttime. Daytime consistency of spatial distribution of active fire occurrence intensity is also higher, while VIIRS V1 and J1 are mostly consistent in the nighttime. V1-derived active fires have the largest occurrence frequency and FAGs proportion at day/night, but the occurrence intensity of J1 active fires is stronger. (4) VIIRS V1 and J1 have higher monitoring accuracy and wider space coverage. The former is more suitable for active fire analysis in the dry season, daytime and nighttime, while the latter has a higher detection level in the rainy season, and MODIS C6 has longer time series.
As a public health emergency, the COVID-19 has led to a devastating consequence, such as casualties and property losses on a global scale. Since February 2020, in order to prevent the spread of the epidemic as well as to promote the resumption of work and production, governments at all levels across China successively decided to take action and introduce the Health QR (quick response) Code Policy. What is known is that the Health QR Code Policy has become an important means and practice for effectively preventing and controlling the disastrous epidemic in China up to now. Based on the Event History Analysis (EHA) of the diffusion time and influencing factors of 295 cities at and above the prefecture level in China, this paper explores the spatio-temporal process and mechanism of the rapid policy implementation in tackling the pandemic across China, what is worth paying attention to is that the policy was first initiated and adopted by a provincial government. The findings are as follows: (1) The cities with higher digitization and economic strength would have a faster response to adopt the Health QR Code Policy. (2) What is worth considering is that the "learning" and "competition" behaviors among governments of neighboring cities would speed up the diffusion of the Health QR Code Policy, while the vertical guidance pressure of provincial governments did not play a significant role. (3) During the COVID-19, policy entrepreneurs have played a significant role in public emergency and become a powerful force that can accelerate the diffusion of Health QR Code Policy. (4) The epidemic situation of each city would affect the transmission rate of the Health QR Code Policy. There is no doubt that the geographical distance from the epidemic hotspots would also affect the governments to adopt the Health QR Code Policy in a short period. This paper, by analyzing the diffusion motivations of the Health QR Code Policy during the COVID-19 pandemic, could provide a predominant summary of experience and policy suggestions for understanding the formulation of emergency policies as well as the diffusion mechanism in the context of public crisis.
