The urban-rural transformation from dichotomy to integration is a gradual process. Like rural areas in many countries, Chinese rural society is experiencing a decline in all spheres due to depopulation, aging, lack of economic opportunity, and so on. Aiming at solving the serious rural issues, China proposed the implementation of a rural revitalization strategy and the promotion of an integrated urban-rural development for the first time in 2017. This proposal marks the transformation of the urban-rural relationship, and the integrated urban-rural development reflects a significant conceptual change. Researches on issues of rural decline are urgently needed to determine the most effective method for rural revitalization and development from the perspective of the urban-rural dynamics. In this context, this paper focuses on studying the theory, technology and management of rural revitalization and development. We construct a theoretical framework for urban-rural integration based on population-land-industry-right between the urban and rural systems, regarding land engineering for land capacity building as the technical support and the rural land system reform and reconstruction as the policy support for management. This research will provide theoretical support for the implementation of China’s rural revitalization strategy.
In view of the lack of comprehensive evaluation and analysis from the combination of natural and human multi-dimensional factors, the urban surface temperature patterns of Changsha in 2000, 2009 and 2016 are retrieved based on multi-source spatial data (Landsat 5 and Landsat 8 satellite image data, POI spatial big data, digital elevation model, etc.), and 12 natural and human factors closely related to urban thermal environment are quickly obtained. The standard deviation ellipse and spatial principal component analysis (PCA) methods are used to analyze the effect of urban human residential thermal environment and its influencing factors. The results showed that the heat island area increased by 547 km2 and the maximum surface temperature difference reached 10.1℃ during the period 2000-2016. The spatial distribution of urban heat island was mainly concentrated in urban built-up areas, such as industrial and commercial agglomerations and densely populated urban centers. The spatial distribution pattern of heat island is gradually decreasing from the urban center to the suburbs. There were multiple high-temperature centers, such as Wuyi square business circle, Xingsha economic and technological development zone in Changsha County, Wangcheng industrial zone, Yuelu industrial agglomeration, and Tianxin industrial zone. From 2000 to 2016, the main axis of spatial development of heat island remained in the northeast-southwest direction. The center of gravity of heat island shifted 2.7 km to the southwest with the deflection angle of 54.9° in 2000-2009. The center of gravity of heat island shifted to the northeast by 4.8 km with the deflection angle of 60.9° in 2009-2016. On the whole, the change of spatial pattern of thermal environment in Changsha was related to the change of urban construction intensity. Through the PCA method, it was concluded that landscape pattern, urban construction intensity and topographic landforms were the main factors affecting the spatial pattern of urban thermal environment of Changsha. The promotion effect of human factors on the formation of heat island effect was obviously greater than that of natural factors. The temperature would rise by 0.293℃ under the synthetic effect of human and natural factors. Due to the complexity of factors influencing the urban thermal environment of human settlements, the utilization of multi-source data could help to reveal the spatial pattern and evolution law of urban thermal environment, deepen the understanding of the causes of urban heat island effect, and clarify the correlation between human and natural factors, so as to provide scientific supports for the improvement of the quality of urban human settlements.
Sensitivity assessment is useful for monitoring land desertification. Research into how to prevent and control desertification is also important. In the arid region of northwest China, desertification is becoming worse and is a serious problem that affects local sustainable development. Based on remote-sensing and geographic information system technology, this study establishes a “soil-terrain-hydrology-climate-vegetation” desertification sensitivity comprehensive evaluation system to reflect the spatiotemporal changes of land desertification, and proposes a spatial distance model to calculate a desertification sensitivity index. The spatiotemporal change characteristics of land desertification sensitivity in northwest China are quantitatively assessed from 2000 to 2017. Moreover, the main driving factors are analyzed using the geographical detector method. The results show the following. (1) Terrain, soil, climate, vegetation and hydrology affect and restrict each other, and constitute the background conditions of the distributions and changes of sensitivity to desertification in northwest China. (2) Desertification sensitivity generally displays a low distribution characteristic on the periphery of the area and a high one in the interior. The low-sensitivity regions are mainly in the five major mountain ranges (Altai Mountains, Tianshan Mountains, Kunlun Mountains, Altun Mountains and Qilian Mountains), while the high-sensitivity regions are mainly in regions such as the Junggar Basin, the Tarim Basin and the Inner Mongolia Plateau, as well as the Taklimakan Desert, Badain Jaran Desert and Tengger Desert. The spatial distribution of desertification sensitivity is obviously regional, and the high- and low-sensitivity regions have clear boundaries and a concentrated distribution. (3) With regard to spatiotemporal evolution, changes in desertification sensitivity since 2000 have been predominantly stable, and the overall sensitivity has displayed a slowly decreasing trend, indicating that potential desertification regions are decreasing annually and that some achievements have been made in the control of regional desertification. (4) Soil and climate play a direct role in the driving factors of desertification in northwest China, and these have been found to be the most important influential factors. Vegetation is the most active and basic factor in changing the sensitivity. In addition, topography and hydrology play a role in restricting desertification changes. Socio-economic factors are the most rapid factors affecting regional desertification sensitivity, and their impacts tend to be gradually increasing. In general, desertification has been effectively controlled in northwest China, and positive results have been achieved in such control. However, against the backdrop of intensified global climate change, increasingly prominent human activities and new normals of socio-economic development, the monitoring, assessment and control of desertification in China still have a long way to go.
Exploring the spatio-temporal dynamics of poverty is important for research on sustainable poverty reduction in China. Based on the perspective of development geography, this paper proposes a panel vector autoregressive (PVAR) model that combines the human development approach with the global indicator framework for Sustainable Development Goals (SDGs) to identify the poverty-causing and the poverty-reducing factors in China. The aim is to measure the multidimensional poverty index (MPI) of China’s provinces from 2007 to 2017, and use the exploratory spatio-temporal data analysis (ESTDA) method to reveal the characteristics of the spatio-temporal dynamics of multidimensional poverty. The results show the following: (1) The poverty-causing factors in China include the high social gross dependency ratio and crop-to-disaster ratio, and the poverty-reducing factors include the high per capita GDP, per capita social security expenditure, per capita public health expenditure, number of hospitals per 10,000 people, rate of participation in the new rural cooperative medical scheme, vegetation coverage, per capita education expenditure, number of universities, per capita research and development (R&D) expenditure, and funding per capita for cultural undertakings. (2) From 2007 to 2017, provincial income poverty (IP), health poverty (HP), cultural poverty (CP), and multidimensional poverty have been significantly reduced in China, and the overall national poverty has dropped by 5.67% annually. there is a differentiation in poverty along different dimensions in certain provinces. (3) During the study period, the local spatial pattern of multidimensional poverty between provinces showed strong spatial dynamics, and a trend of increase from the eastern to the central and western regions was noted. The MPI among provinces exhibited a strong spatial dependence over time to form a pattern of decrease from northwestern and northeastern China to the surrounding areas. (4) The spatio-temporal networks of multidimensional poverty in adjacent provinces were mainly negatively correlated, with only Shaanxi and Henan, Shaanxi and Ningxia, Qinghai and Gansu, Hubei and Anhui, Sichuan and Guizhou, and Hainan and Guangdong forming spatially strong cooperative poverty reduction relationships. These results have important reference value for the implementation of China’s poverty alleviation strategy.
Physical geography is a basic research subject of natural sciences. Its research object is the natural environment which is closely related to human living and development, and China’s natural environment is complex and diverse. According to national needs and regional development, physical geographers have achieved remarkable achievements in applied basis and applied research, which also has substantially contributed to the planning of national economic growth and social development, the protection of macro ecosystems and resources, and sustainable regional development. This study summarized the practice and application of physical geography in China over the past 70 years in the following fields: regional differences in natural environments and physical regionalization; land use and land cover changes; natural hazards and risk reduction; process and prevention of desertification; upgrading of medium- and low-yield fields in the Huang-Huai-Hai region; engineering construction in permafrost areas; geochemical element anomalies and the prevention and control of endemic diseases; positioning and observation of physical geographical elements; and identification of geospatial differentiation and geographical detectors. Furthermore, we have proposed the future direction of applied research in the field of physical geography.
Giant clam shell mining (GCSM), a unique phenomenon occurring at remote coral reefs in the southern South China Sea (SCS), forms striking scars on the reef flats and damages the reef flat substrate. Through image analyses at three times (2004.02.02, 2014.02.26, and 2019.04.10) and in situ surveys at Ximen Reef, a representative site that has experienced GCSM, we quantified the GCSM-generated substrate damage and the corresponding recovery. GCSM was estimated to have occurred sometime between 2012 and 2014, causing reduction in live coral subarea and formation of micro-relief as trenches and mounds. GCSM-generated damage was restricted to the reef flat. After GCSM, coral and algae subarea increased, and the trenches and mounds tended to be filled and eroded, representing a natural recovery of the substrate. The legal prohibition on human disturbances at the coral reefs contributed to substrate recovery at Ximen Reef. This case also implied that recovery of the other coral reefs that suffered from GCSM is possible.
A largely unexplored application of “Big Data” in urban contexts is using human mobility data to study temporal heterogeneity in intercity travel networks. Hence, this paper explores China’s intercity travel patterns and their dynamics, with a comparison between weekdays and holidays, to contribute to our understanding of these phenomena. Using passenger travel data inferred from Tencent Location Big Data during weekdays (April 11-15, 2016) and National Golden Week (October 1-7, 2016), we compare the spatial patterns of Chinese intercity travel on weekdays and during Golden Week. The results show that the average daily intercity travel during Golden Week is significantly higher than that during weekdays, but the travel distance and degree of network clustering are significantly lower. This indicates temporal heterogeneity in mapping the intercity travel network. On weekdays, the three major cities of Beijing, Shanghai, and Guangzhou take prominent core positions, while cities that are tourism destinations or transportation hubs are more attractive during Golden Week. The reasons behind these findings can be explained by geographical proximity, administrative division (proximity of cultural and policy systems), travel distance, and travel purposes.
In China's Loess Plateau severe gully erosion (LPGE) region, the shoulder-line is the most intuitive and unique manifestation of the loess landform, which divides a landform into positive and negative terrains (PNTs*The spatial combination model of PNTs is of great significance for revealing the evolution of the loess landform. This study modeled and proposed the Surface Nibble Degree (SND), which is a new index that reflects the comparison of the areas of PNTs. Based on 5 m DEMs and matched high-resolution remote sensing images, the PNTs of 172 complete watersheds in the LPGE were extracted accurately, and the SND index was calculated. The spatial distribution trend of SND was discussed, and the relationship between SND and the factors that affect the evolution mechanism of regional landform was explored further. Results show that: (1) The SND can be calculated formally. It can quantify the development of the loess landform well*2) The SND of the LPGE has evident spatial differentiation that increases from southwest to northeast. High values appear in Shenmu of Shaanxi, Shilou of Shanxi, and northern Yanhe River, whereas the low values are mainly distributed in the southern loess tableland and the inclined elongated ridge area of Pingliang in Gansu and Guyuan in Ningxia*3) In the Wuding River and Yanhe River, the SND decreases with the increase in flow length (FL*In the North-Luohe River and Jinghe River, the SND increases with FL*4) SND is significantly correlated with gully density and sediment modulus and moderately correlated with hypsometric integral. As for the mechanism factors analysis, the relationship between loess thickness and SND is not obvious, but SND increased first and then decreased with the increase of precipitation and vegetation in each geographical division, and we found that the land use type of low coverage grassland has greater erosion potential.
This study uses two forms of the Palmer Drought Severity Index (PDSI), namely the PDSI_TH (potential evapotranspiration estimated-by the Thornthwaite equation) and the PDSI_PM (potential evapotranspiration estimated by the FAO Penman-Monteith equation), to characterize the meteorological drought trends during 1960-2016 in the Loess Plateau (LP) and its four subregions. By designing a series of numerical experiments, we mainly investigated various climatic factors' contributions to the drought trends at annual, summer, and autumn time scales. Overall, the drying trend in the PDSI_TH is much larger than that in the PDSI_PM. The former is more sensitive to air temperature than precipitation, while the latter is the most sensitive to precipitation among all meteorological factors. Increasing temperature results in a decreasing trend (drying) in the PDSI_TH, which is further aggravated by decreasing precipitation, jointly leading to a relatively severe drying trend. For the PDSI_PM that considers more comprehensive climatic factors, the drying trend is partly counteracted by the declining wind speed and solar radiation. Therefore, the PDSI_PM ultimately shows a much smaller drying trend in the past decades.
Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and socioeconomic databases of the counties in Beijing-Tianjin-Hebei region, this paper comprehensively calculates the environmental stress index (ESI) for the urban agglomeration using the entropy weight method (EWM) at the county scale and analyzes the spatiotemporal patterns and the differences among the four types of major functional zones (MFZ) for the period 2012-2016. In addition, the socioeconomic driving forces of environmental stress are quantitatively estimated using the geographically weighted regression (GWR) method based on the STIRPAT model framework. The results show that: (1) The level of environmental stress in the Beijing-Tianjin-Hebei region was significantly alleviated during that time period, with a decrease in ESI of 54.68% by 2016. This decrease was most significant in Beijing, Tangshan, Tianjin, Shijiazhuang, and other central urban areas, as well as the Binhai New Area. The level of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated by 2016. (2) The spatial spillover effect of environmental stress increased further at the county scale from 2012 to 2016, and spatial locking and path dependence emerged in the cities of Tangshan and Tianjin. (3) Urbanized zones (development-optimized and development-prioritized zones) were the major areas bearing environmental pollution in the Beijing-Tianjin-Hebei region in that time period. The ESI accounted for 65.98% of the whole region, where there was a need to focus on the prevention and control of environmental pollution. (4) The driving factors of environmental stress at the county scale included population size and the level of economic development. In addition, the technical capacity of environmental waste disposal, the intensity of agricultural production input, the intensity of territorial development, and the level of urbanization also had a certain degree of influence. (5) There was spatial heterogeneity in the effects of the various driving factors on the level of environmental stress. Thus, it was necessary to adopt differentiated environmental governance and reduction countermeasures in respect of emission sources, according to the intensity and spatiotemporal differences in the driving forces in order to improve the accuracy and adaptability of environmental collaborative control in the Beijing-Tianjin-Hebei region.
Modern railway projects, characterized by “natural monopoly”, large investment, and far-reaching influences, are highly dependent on the institutional and cultural environments in China. The countries along the Belt and Road are characterized by weak institutions, unstable politics, and poor technology foundations, which are largely different from China. These factors are severe obstacles to international technology transfer. By summarizing the experiences from the Mombasa-Nairobi Standard-Gauge Railway (SGR) project, this study proposes a framework for embedded technology transfer with a technology-institution-culture nexus. The results indicate that technology localization, including technology standards, management mode, and industrial chain, should be realized in the process of technology transfer. Then, the host government ought to overhaul its institutional and policy framework to support the infrastructure projects. Moreover, the cultural conflicts between the transferor and transferee should be taken seriously. This experience could provide references for other international infrastructure technology transfers.
In the past 40 years, cultivated land has faced the continued anthropogenic interference, which has become a significant issue for cultivated land preservation during rapid urbanization. The purpose of this research was to reveal the spatio-temporal evolutionary characteristics of cultivated land and the correlation between rural population variation and farmland change in China. Fifty county-level administrative units in Zhejiang Province were selected as the study area wherein spatio-temporal evolution comparative analysis for every 5 years from 2000 to 2015 was conducted. This study used the pool method to estimate the impacts of the rural population variation, average slope, average elevation, rural residential disposable income, primary industry proportion, and road density on farmland utilization efficiency from the spatial perspective, which is represented by landscape metrics including the mean patch size, edge density, area weighted mean shape index, and area weighted mean patch fractal dimension. This study showed that the cultivated land landscape index continued to rise after 2000 and then started decreasing after 2010, indicating a reduction in human interference after 2010. The spatial variation of rural population of all county-level administrative units decreased from 2000 to 2010, and 62% of them began to increase after 2010. The regression analysis results showed that the spatial variation of rural population was significantly and negatively correlated with the cultivated land landscape while the rural residential disposable income, average slope and primary industry proportion were all significantly and positively related to the cultivated land landscape index. The results implied that the loss of the agricultural labor force and the difficulty of sloping farmlands adapting to mechanized farming were unconducive to farmland utilization efficiency improvement, and the increase in nonagricultural activities in rural areas would increase the difficulty of cultivated land preservation. Our analysis suggests that local governments should improve the production efficiency of fragmented land or strengthen the construction control of housing and facilities in rural areas according to their regional urbanization development situation.
Since the implementation of the economic reform and opening up policy in 1978, China has miraculously created long-term high-speed economic growth, but has also had to face the problem of excessive consumption of resources as well as an intensification of environmental pollution. As a result, China is now facing a slowdown in development. China must maintain a certain speed of development to realize its goal of being a powerful nation, and becoming a developed country by 2050. To this end, China is facing a transformation of its economic development. There is a need to agree on an expected economic growth rate, along with the corresponding development modes or means of regulation in the medium- and long-term periods. This study developed a systematic-dynamic model to simulate the coupling relationship between economic growth, development modes, and the environmental supply system, and explored the possible options for future economic growth as well as the resource use and environmental protection requirements (the main factors). The results showed that to achieve the development goal of becoming a developed country by 2050, while maintaining a good ecological environment, the suitable growth rate for China's economy is 3.8%-6.3%. Within this range, a growth rate of 3.8%-4.4% was found to be relatively safe, while a growth rate of 4.4%-6.3% required further technical progress. This study provides an early warning in regard to China's environmental and development status. The study was a response to the “Future Earth” framework document and, in terms of development speed, it developed a theoretical system for the determination of resource and environmental carrying capacity (RECC).
Payments for Ecosystem Services (PES) programs have been implemented in both developing and developed countries to conserve ecosystems and the vital services they provide. These programs also often seek to maintain or improve the economic wellbeing of the populations living in the corresponding (usually rural) areas. Previous studies suggest that PES policy design, presence or absence of concurrent PES programs, and a variety of socioeconomic and demographic factors can influence decisions of households to participate or not in the PES program. However, neighborhood impacts on household participation in PES have rarely been addressed. This study explores potential neighborhood effects on villagers’ enrollment in the Grain-to-Green Program (GTGP), one of the largest PES programs in the world, using data from China’s Fanjingshan National Nature Reserve. We utilize a fixed effects logistic regression model in combination with the eigenvector spatial filtering (ESF) method to explore whether neighborhood size affects household enrollment in GTGP. By comparing the results with and without ESF, we find that the ESF method can help account for spatial autocorrelation properly and reveal neighborhood impacts that are otherwise hidden, including the effects of area of forest enrolled in a concurrent PES program, gender and household size. The method can thus uncover mechanisms previously undetected due to not taking into account neighborhood impacts and thus provides an additional way to account for neighborhood impacts in PES programs and other studies.
Land use and land cover (LULC) alteration has changed original energy balance and heat fluxes between land and atmosphere, and thus affects the structure characteristics of temperature and humidity fields over urban heterogeneous surfaces in different spatio-temporal scales. Lanzhou is the most typical river valley city of China, it is chosen as the case study. Typical river valley terrain, rapid urbanization and severe air pollution have caused unique urban climate and urban heat island (UHI) effects in Lanzhou. Firstly, the spatial structure characteristics and dynamic evolution of temperature and humidity fields in autumn are simulated by mobile measurement experiment and GIS spatial analysis method. The results show that temperature and humidity fields have significant dynamic change within a day, and have multiple center and multiple intensity level characteristics. Then, LULC and normalized difference vegetation index (NDVI) are extracted from remote sensing images, the distribution patterns of temperature and humidity fields have close relationships with LULC and NDVI. Moreover, there is a significant positive correlation between impervious surface area and thermal field intensity. A positive correlation between NDVI value and humidity field intensity has been found as well as a negative correlation between NDVI value and thermal field intensity. Finally, heat fluxes and energy balance characteristics between ground and atmosphere are analyzed based on the Bowen-ratio System experiments. This study could provide theoretical support and practical guidance for urban planning, urban eco-environment construction and air pollution prevention of river valley city.
Water retention is important in forest ecosystem services. The heterogeneity analysis of water-retention capacity and its influencing factors is of great significance for the construction of water-retention functional areas, restoration of vegetation, and the protection of forest ecosystems in the Beijing-Tianjin-Hebei region. A total of 1366 records concerning water-retention capacity in the canopy layer, litter layer, and soil layer of forest ecosystem in this region were obtained from 193 literature published from 1980 to 2017. The influencing factors of water-retention capacity in each layer were analyzed, and path analysis was used to investigate the contribution of the factors to the water-retention capacity of the three layers. The results showed that mixed forests had the highest water-retention capacity, followed by broad-leaved forests, coniferous forests, and shrub forests. In addition, no matter the forest type, the ranking of the water-retention capacity was soil layer, canopy layer, and litter layer from high to low. The main influencing factors of water-retention capacity in forest canopy were leaf area index and maximum daily precipitation (R 2=0.49), and the influencing coefficients were 0.34 and 0.30, respectively. The main influencing factors of water-retention capacity in the litter layer were semi-decomposed litter (R 2=0.51), and the influencing coefficient was 0.51. The main influencing factors of water-retention capacity in the soil layer were non-capillary porosity and soil depth (R 2=0.61), the influencing coefficients were 0.60 and 0.38, respectively. This study verifies the simulation of the water balance model or inversion of remote sensing of the water-retention capacity at the site scale, and provides scientific basis for further study of the impact of global change on water retention.
Global large-scale urbanization and climate change have become indisputable scientific facts yet are unresolved issues, and are a common concern for mankind. The relationship between these two topics is unclear and it is not known how to deal appropriately at the scientific level with climate change in the process of urbanization. Further exploration of the science, management and practice, are needed to achieve global and regional sustainable development. This paper first considers the basic facts concerning mass urbanization and climate change and summarizes the interactions and possible mechanisms of urbanization and climate change. Urbanization leads to the heat island effect, an uneven distribution of precipitation and extreme weather, together with a local-regional-global multi-scale superposition effect, which aggravates the consequences of global climate change. The impact of climate change on urbanization is mainly manifested in aspects such as changes of energy consumption, mortality, and the spread of infectious diseases, sea level rise, extreme weather damage to infrastructure, and water shortages. This paper also briefly reviews relevant international research programs and action coalitions and puts forward an analysis framework of multi-dimensional sustainable urbanization which can adapt to and mitigate climate change, from the perspective of the four key dimensions—population, land use, economy, and society. It is imperative that we strengthen the interdisciplinary activities involving the natural and social sciences, take urbanization and other human activities into consideration of the land - atmosphere system, and explore the human-land-atmosphere coupling process. The adaptation and mitigation from the perspective of human activities, as represented by urbanization, might be the most critical and realistic way to deal with climate change.
Understanding the manifestations and underlying drivers of agricultural land use change in China is of great importance for both domestic and global food security. However, little is known about the holistic pattern of agricultural land use change across China, especially from the perspective of intensity since the evidence has been gathered mainly through case studies at local levels. This study conducts a systemic review of agricultural land use change and its underlying drivers in China by aggregating 169 relevant case studies from 123 publications. The cases related to intensification and disintensification, which are the two types of agricultural land use change, are generally equal, accounting for 50% of the total number of cases. Intensification and disintensification can be further divided into the same three categories: expansion/contraction of agricultural land, changes in agricultural land use activities and changes in land management intensity. Demographic, economic, technological, and institutional drivers, together with location factors, are frequently noted as significant underlying drivers, while sociocultural drivers and farm(er) characteristics are less frequently recognized. Finally, three major land use change trajectories are summarized mainly concerning rising labor costs and the concomitant increase in off-farm employment, the ecological improvement policy, and advances in agricultural technology.
Based on a total of 519 images, the composite images with the lowest possible cloud cover were generated at pixel level with image synthesis method on Google Earth Engine (GEE) platform. The Remote Sensing Ecological Index (RSEI) was adopted, and calculated in an efficient way with the assistance of parallel cloud computing of the GEE platform. The RSEI was used in this paper to evaluate and monitor the eco-environmental quality of the Lhasa Metropolitan Area. Results show that: (1) The ecological quality is better in the west than in the east of Lhasa Metropolitan Area, with Lhasa as an approximate dividing point. The ecological quality improved and then deteriorated dramatically before 2000, with the mean RSEI value dropping from 0.51 to 0.46; the trend was followed by a gradual increase up until 2017, with the mean RSEI value increased from 0.46 to 0.55. (2) The RSEI is weakly and positively correlated with socioeconomic indicators. This indicates that the population growth and economic development did not negatively influence the ecological quality, but actually boosted it. (3) The GEE can serve as an efficient computing platform for the assessment and monitoring of eco-environmental quality in vast regions.
As one of the most critical impact factors of global change, historical land-use change is an indispensable input in climate and environment simulations. To better understand the cropland change in the Guanzhong area, gazetteers, statistics, and survey data were collected as data sources. Methods of registered tax-paying cropland data collection, selection of time points, and data interpolation and calibration were used to reconstruct changes in the cropland area. The cropland area data at the county level were allocated to 1 km×1 km grid cells. The total cropland area in the Guanzhong area was influenced by changes in population, wars, natural disasters, and land-use types, and it fluctuated from 1650 to 2016. From 1780 to 1830, the cropland expanded in the northern and western parts of Guanzhong area, and the cropland in the north of Qinling Mountains increased slightly. The spatial pattern of cropland reached its maximum range in 1980, and the cropland area declined in the whole study area, especially in the cities of Xi’an and Xianyang in 2016. The comparison between HYDE 3.2 and the data obtained in this study showed that the grid cells of HYDE 3.2 exhibit lower values of cropland area fractions in the Guanzhong Basin and higher values in high-altitude areas around the Guanzhong Basin as compared to those in this study.
Land cover change has presented clear spatial differences in the New Eurasian Continental Bridge Economic Corridor (NECBEC) region in the 21st century. A spatiotemporal dynamic probability model and a driving force analysis model of land cover change were developed to analyze explicitly the dynamics and driving forces of land cover change in the NECBEC region. The results show that the areas of grassland, cropland and built-up land increased by 114.57 million ha, 8.41 million ha and 3.96 million ha, and the areas of woodland, other land, and water bodies and wetlands decreased by 74.09 million ha, 6.26 million ha, and 46.59 million ha in the NECBEC region between 2001 and 2017, respectively. Woodland and other land were mainly transformed to grassland, and grassland was mainly transformed to woodland and cropland. Built-up land had the largest annual rate of increase and 50% of this originated from cropland. Moreover, since the Belt and Road Initiative (BRI) commenced in 2013, there has been a greater change in the dynamics of land cover change, and the gaps in the socio-economic development level have gradually decreased. The index of socio-economic development was the highest in western Europe, and the lowest in northern Central Asia. The impacts of socio-economic development on cropland and built-up land were greater than those for other land cover types. In general, in the context of rapid socio-economic development, the rate of land cover change in the NECBEC has clearly shown an accelerating trend since 2001, especially after the launch of the BRI in 2013.
The theory on the cyclic adaptation between society and ecosystems sheds new light on the evolution and internal structure of human-environment systems. This paper introduces the risk index (RI) and adaptation capacity index (ACI) to evaluate the rural human-environment system. An evaluation index system for the adaptability of rural human-environment systems is configured in the context of climate change and policy implementation. On this basis, the stages, features, dominant control factors, and evolution mechanism were examined vis-à-vis the adaptability of the rural human-environment system in Darhan Muminggan Joint Banner from 1952 to 2017. The main results are as follows: (1) The evolution of the rural human-environment system can be divided into three stages, namely, the reorganization and rapid development stage (1952-2002) with population, cultivated land, livestock and degraded grassland increasing by 260%, 13%, 134% and 16.33%, respectively. The rapid to stable development stage (2003-2010) with population increasing by 2.8%; cultivated land, livestock and degraded grassland decreasing by 2.3%, 13.6% and 10.7%, respectively. The stable to release stage (2011-2017) with population, cultivated land, livestock and degraded grassland decreasing by 2.6%, 0.2%, 10.6% and 3.8%, respectively. (2) With the passage of time, the ACI of the rural human-environment system first increased slightly (-0.016-0.031), followed by a slight decline (0.031-0.003), and culminating in a rapid increase (0.003-0.088). In terms of spatial patterns, adaptability is high in the middle, moderate in the north, and low in the south. (3) The evolution of adaptability in the rural human-environment system was mainly controlled by the per capita effective irrigation area (22.31%) and the per capita number of livestock (23.47%) from 1990 to 2000, the desertified area (25.06%) and the land use intensity (21.27%) from 2000 to 2005, and the per capita income of farmers and herdsmen (20.08%) and the per capita number of livestock (18.52%) from 2010 to 2007. (4) Under the effects of climate change and policy interventions, the cyclic adaptation of the rural human-environment system was propelled by the interactions between two kinds of subjects: farmers and herdsmen on the one hand and rural communities on the other hand. The interaction affects the adaptive behavior of the two kinds of subjects, which in turn drives the cyclic evolution of the system. As a result, the system structure and functions developed alternatively between coordinated and uncoordinated states. Small-scale adaptive behaviors of farmers and herdsmen have a profound impact on the evolution of the rural human-environment system.
As one of the most ecologically sensitive issues in the world, migration now plays an important role in population growth on the Qinghai-Tibet Plateau. To promote sustainable development in the world’s third pole, it is necessary to investigate population migration on the Plateau. Using 2010 census data, a spatial database of county-level migrants on the Plateau was constructed, and migrants were divided into short-distance and long-distance migrants according to the hukou-registered origins. Measuring migration intensity allowed the spatial pattern of population migration on the Plateau to be ascertained. The driving factors were identified using spatial regression models, and the main conclusions are as follows: (1) In 2010, there were 1.23 million inter-county migrants on the Qinghai-Tibet Plateau, and the overall migration intensity reached 10.50%. There existed significant spatial differences in population migration intensity on the Plateau at that time, and the provincial or prefectural capitals were attractive destinations for migrants. Northwestern Qinghai, which boasted mining industries, constituted a significant spatial cluster with a relatively high migration intensity. However, most areas on the Plateau attracted relatively few migrants, especially in western and northern parts of Tibet, which were sparsely populated and uninhabitable. (2) There were 0.95 million short-distance migrants and 0.28 million long-distance migrants. The short-distance migration intensity was 8.14%, while the long-distance migration intensity was only 2.36%. Short-distance migration was the main form of population migration, with a pattern similar to the layout of overall population migration intensity. Only a few county-level units strongly attracted long-distance migrants, which were mostly distributed in northwestern Qinghai. (3) Economic factors were considered fundamental drivers for migrants to live on the Plateau. Destinations with high levels of economic development and more opportunities in non-agricultural jobs proved more attractive for migrants. For short-distance migrants, urbanization level also proved a considerable driving factor for in-migration. However, long-distance migrants were mainly affected by the job chances of the secondary industry on the Qinghai-Tibet Plateau.
Developing a comprehensive understanding of inter-city interactions is crucial for regional planning. We therefore examined spatiotemporal patterns of population migration across the Qinghai-Tibet Plateau (QTP) using migration big data from Tencent for the period between 2015 and 2019. We initially used decomposition and breakpoint detection methods to examine time-series migration data and to identify the two seasons with the strongest and weakest population migration levels, between June 18th and August 18th and between October 8th and February 15th, respectively. Population migration within the former period was 2.03 times that seen in the latter. We then used a variety of network analysis methods to examine population flow directions as well as the importance of each individual city in migration. The two capital cities on the QTP, Lhasa and Xining, form centers for population migration and are also transfer hubs through which migrants from other cities off the plateau enter and leave this region. Data show that these two cities contribute more than 35% of total population migration. The majority of migrants tend to move within the province, particularly during the weakest migration season. We also utilized interactive relationship force and radiation models to examine the interaction strength and the radiating energy of each individual city. Results show that Lhasa and Xining exhibit the strongest interactions with other cities and have the largest radiating energies. Indeed, the radiating energy of the QTP cities correlates with their gross domestic product (GDP) (Pearson correlation coefficient: 0.754 in the weakest migration season, WMS versus 0.737 in the strongest migration season, SMS), while changes in radiating energy correlate with the tourism-related revenue (Pearson correlation coefficient: 0.685). These outcomes suggest that level of economic development and level of tourism are the two most important factors driving the QTP population migration. The results of this analysis provide critical clarification guidance regarding huge QTP development differences.
Since the launch of China’s reform and opening up policy, the process of urbanization in China has accelerated significantly. With the development of cities, inter-city interactions have become increasingly close, forming urban agglomerations that tend to be integrated. Urban agglomerations are regional spaces with network relationships and hierarchies, and have always been the main units for China to promote urbanization and regional coordinated development. In this paper, we comprehensively consider the network and hierarchical characteristics of an urban agglomeration, while using urban flow to describe the interactions of the inter-city networks and the hierarchical generalized linear model (HGLM) to reveal the hierarchical driving mechanism of the urban agglomeration. By coupling the HGLM with a cellular automata (CA) model, we introduced the HGLM-CA model for the simulation of the spatial expansion of an urban agglomeration, and compared the simulation results with those of the logistic-CA model and the biogeography-based optimization CA (BBO-CA) model. According to the results, we further analyzed the advantages and disadvantages of the proposed HGLM-CA model. We selected the middle reaches of the Yangtze River in China as the research area to conduct this empirical research, and simulated the spatial expansion of the urban agglomeration in 2017 on the basis of urban land-use data from 2007 and 2012. The results indicate that the spatial expansion of the urban agglomeration can be attributed to various driving factors. As a driving factor at the urban level, urban flow promotes the evolution of land use in the urban agglomeration, and also plays an important role in regulating cell-level factors, making the cell-level factors of different cities show different driving effects. The HGLM-CA model is able to obtain a higher simulation accuracy than the logistic-CA model, which indicates that the simulation results for urban agglomeration expansion considering urban flow and hierarchical characteristics are more accurate. When compared with the intelligent algorithm model, i.e., BBO-CA, the HGLM-CA model obtains a lower simulation accuracy, but it can analyze the interaction of the various driving factors from a hierarchical perspective. It also has a strong explanatory effect for the spatial expansion mechanism of urban agglomerations.
The glacier is a crucial freshwater resource in arid and semiarid regions, and the vulnerability of the glacier change is intimately linked to regional ecological services and socio-economic sustainability. Taking the Tianshan Mountains region in China as an example, a basic framework for studying the vulnerability of glacier change was constructed so as to address factors such as physical geography, population status, socio-economic level, agricultural development, and social services. The framework was based on key dimensions, that is, exposure, sensitivity, and adaptability, and this constituted a targeted evaluation index system. We examined the spatial structure and spatial autocorrelation of the glacier change vulnerability using ArcGIS and GeoDa software. The influence and interaction of natural, social, economic, population and other factors on glacier change adaptability was examined using the GeoDetector model. The results suggested the following: (1) The vulnerability level decreased from the western region to the eastern region with significant differences between the two regions. The eastern region had the lowest vulnerability, followed by the central region, and then western region which had the highest vulnerability. (2) Significant positive and negative correlations were found between exposure, sensitivity, and adaptability, indicating that the areas with high exposure and high sensitivity to glacier change tended to have a low adaptive capacity, which led to high vulnerability, and vice versa. (3) The spatial heterogeneity regarding the ability to cope with glacier change reflected the combined effects of the natural, social, economic, and demographic factors. Among them, factors such as the production value of secondary and tertiary industries, the urban population, urban fixed-asset investment, and the number of employees played major roles regarding the spatial heterogeneity of glacier change.
This article contributes to a small but growing body of multi-sited and multi-scalar research on the Belt and Road Initiative. We focus on relations at the national, regional and international scales, and present original research from China and Turkey, to show how the Istanbul-Ankara high-speed railway has served as a testing ground for China’s Belt and Road Initiative (BRI). Its construction was initially funded by the European Investment Bank, but it is now part of the backbone of the Turkish Government’s Middle Corridor plan which enhances west-east connectivity and integration with the Caucasus and Central Asia. We show that in contrast to multinational corporations from the OECD that seek to remain footloose, Chinese state-owned enterprises (SOEs) seek to adapt to, apprehend and ultimately shape local institutions. In the case of Turkey this proved difficult given its institutional alignment with the European Union. Thus, while the railway project was completed successfully by a consortium led by a Chinese SOE, Turkey’s dynamic and complex regulatory environment discourages Chinese SOEs in the infrastructure sector. We conclude that the Turkish and Chinese governments are currently pursuing complementary territorial visions yet their cooperation is project-based and pragmatic.
Urban forests play an important role in the thermal comfort and overall life of local populations in large- and medium-sized cities. This study analyzes urban forest loss and maps land use and land cover (LULC) changes between 1991 and 2018 by evaluating the use of urban planning instruments for the mitigation of urban forest loss in João Pessoa, Brazil. For this purpose, satellite-derived LULC images from 1991, 2006, 2010 and 2018 and data on urban forest loss areas obtained using the Google Earth Engine were used. In addition, this paper also discusses the instruments used for integrated urban planning, which are (a) the legal sector, responsibility and nature; (b) the urban expansion process; and (c) the elements of urban infrastructure. The results show a clear shift in land use in the study area. The major changes in LULC classes occurred in urban areas and herbaceous vegetation, while the greatest loss was in arboreal/shrub vegetation. Thus, an increase in the pressure to occupy zones intended for environmental preservation could be estimated. Our results showed similar accuracies with other studies and more spatial details. The characteristics of the patterns, traces, and hotspots of urban expansion and forest cover loss were explored. We highlighted the potential use of this proposed framework to be applied and validated in other parts of the world to help better understand and quantify various aspects of urban-related problems such as urban forest loss mapping using instruments for integrated urban planning and low-cost approaches.
Mobile internet and wireless communication technologies have produced unprecedented location-aware data. Such big geospatial data can be used as a proxy measure of the ‘digital footprints’ left by us on the planet and provide a valuable opportunity to understand the dynamic and short-term human disturbance on the nature at fine scales. This study investigated the spatiotemporal variations of human’s digital footprints on the Qinghai-Tibet Plateau using smartphone-users-generated Tencent’s location request data. The results showed that human’s digital footprints cover less than 5% of Qinghai and Tibet, exhibiting either a U-shaped or an N-shaped temporal change pattern during the major festivals. Spatial changes of the digital footprints manifested a transition process from dispersion to concentration in Xining and Lhasa. Human disturbance assessment of seven large nature reserves on the plateau showed that the Qinghai Lake is the most disturbed one as shown by 14.6% of its area is stained with human digital footprints and the areal average of footprint intensity is 1.59, and the disturbance was significantly escalated during the National Day holiday. By contrast, the Qangtang and Hoh Xil are the least affected nature reserves with the two indices less than 1% and 0.1, respectively.
The Yarlung Zangbo River Basin (YZRB) is a key ecological protection area on the Qinghai-Tibet Plateau (QTP). Determination of the ecosystem service values (ESVs) can help recognize the benefits of sustainable management. It is gradually becoming the main path that constructs plateau spatial planning of integrating ecological protection, and achieves global sustainable development goals (SDGs) in China. In this paper, the spatio-temporal dynamic evolutions of the ESVs were estimated on the multiple scales of “basin, subbasin and watershed” from 1980 to 2015. The main factors influencing ESVs were explored in terms of physical geography, human activities, and climate change. It had been proposed that sustainable spatial planning including ecological protection, basin management, and regional development was urgent to set up. Our results show that the increase in wetland and forest and results in an increase of 9.4% in the ESVs. Attention should be paid to the reduction of water and grassland. Water conservation (WC), waste treatment (WT), and soil formation and conservation (SFC) are the most important ecosystem services in the YZRB. At present, the primary problem is to solve the ESVs decreasing caused by glacier melting, grassland degradation, and desertification in the upper reaches region. The middle reaches should raise the level of supply services. Regulation services should be increased in the lower reaches region on the premise of protecting vegetation. The ESVs in adjacent watersheds are interrelated and the phenomenon of “high agglomeration and low agglomeration” is obvious, existing hot-spots and cold-spots of ESVs. Additionally, when the altitude is 4500-5500 m, the temperature is 3-8°C, and the annual precipitation is 350-650 mm, ESVs could reach its maximum. A framework of sustainable plateau spatial planning could provide references to delimit the ecological protection red line, key ecological function zone, and natural resource asset accounting on the QTP.
