Landscape is a dynamic phenomenon that almost continuously changes. The overall change of a landscape is the result of complex and interacting natural and spontaneous processes and planned actions by man. However, numerous activities by a large number of individuals are not concerted and contribute to the autonomous evolution of the landscape in a similar way as natural processes do. There is a well-established need to detect land use and ecological change so that appropriate policies for the regional sustainable development can be developed. Landscape change detection is considered to be effectively repeated surveillance and needs especially strict protocols to identify landscape change. This paper developed a series of technical frameworks on landscape detection based on Landsat Thematic Mapper (TM) Data. Through human-machine interactive interpretation, the interpretation precision was 92.00% in 1986 and 89.73% in 2000. Based on the interpretation results of TM images and taking Yulin prefecture as a case study area, the area of main landscape types was summarized respectively in 1986 and 2000. The landscape pattern changes in Yulin could be divided into ten types.

The features of physical geography in the transitional region between Qinling Mountains and Huanghuai Plain possess transitional characters evidently in two directions: one is from the western mountain to the eastern plain and the other is from southern subtropical zone to northern temperate zone. Torrential rain, especially strong torrential rain is frequent in the transitional region, and there are many torrential rain centers. A majority of torrential rain is distributed among 100-200 m asl. The winter temperature at 100-400 m asl is higher than that in Huanghuai Plain whose altitude is lower than that of the transitional region, and the highest temperature in January appears at 350-400 m asl. The thickness of warm slope belt in the transitional region varies from 100 m to 250 m asl. The formation of torrential rain and warm slope belt is the result of joint action of atmospheric circulation and local terrain. Frequent torrential rains and warm slope belt had tremendous influences on the soil properties, plant distribution and local climate in the transitional region.

Scenario modelling and the risk assessment of natural disasters is one of the hotspots in disaster research. However, up until now, urban natural disaster risk assessments lack common procedures and programmes. This paper selects rainstorm waterlogging as a disaster to research, which is one of the most frequently occurring hazards for most cities in China. As an example, we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing’an District of Shanghai. Based on the basic concept of disaster risk, this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods. Through this analysis of vulnerability and exposure, we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments. A grid-based Geographical Information System (GIS) approach, including an urban terrain model, an urban rainfall model and an urban drainage model, was applied to simulate inundation area and depth. Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys, which were further applied to analyse vulnerability, exposure and loss assessment. Finally, the exceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities. A framework was also developed for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss. This is a new exploration for small-scale urban natural disaster scenario simulation and risk assessment.

Based on the statistics of glacier area variation measured in the Chinese Tianshan Mountains since 1960, the response of glacier area variation to climate change is discussed systematically. As a result, the total area of the glaciers has been reduced by 11.5% in the past 50 years, which is a weighted percentage according to the glacier area variations of 10 drainage basins separated by the Glacier Inventory of China (GIC). The annual percentage of area changes (APAC) of glaciers in the Chinese Tianshan Mountains is 0.31% after the standardization of the study period. The APAC varies widely for different drainage basins, but the glaciers are in a state of rapid retreat, generally. According to the 14 meteorological stations in the Chinese Tianshan Mountains, both the temperature and precipitation display a marked increasing tendency from 1960 to 2009 at a rate of 0.34℃·(10a)^-1 and 11 mm·(10a)^-1, respectively. The temperature in the dry seasons (from November to March) increases rapidly at a rate of 0.46℃·(10a)^-1, but the precipitation grows slowly at 2.3 mm·(10a)^-1. While the temperature in the wet seasons (from April to October) grows at a rate of 0.25 ℃·(10a)^-1, but the precipitation increases at 8.7 mm·(10a)^-1. The annual and seasonal climatic trends accelerate the retreat of glaciers.

One of the noticeable consequences of China's opening up and integration into the world economy has been an explosive demand for intellectual dialogue and knowledge exchange between China and the outside world. Despite this new demand for globalization in knowledge production, existing geographical research undertaken within and outside China has remained by and large separated because of the formidable barriers of different ideological convictions, linguistic and cultural traditions, and paradigms and practices of knowledge production. In the studies of economic geography, the gap between China and the Western world has remained so pronounced that a “bridge” or a “common ground” is badly needed (Yeung and Lin, 2003; Liu, 2009; Lin, 2009a). This situation will become self-evident when one compares the Chinese journal Jingji Dili with the English journal Economic Geography— two journals with the same title and yet totally different contents to address different audience. Against this backdrop, World Economic Geography produced by Du Debin and his associates stands out as a timely, bold, and ground-breaking contribution that fills an awkward gap existing between China and the Western world in the studies of economic geography.

Development of Xiong'an New District (XND) is integral to the implementation of the Beijing-Tianjin-Hebei (BTH) Integration Initiative. It is intended to ease the non-capital functions of Beijing, optimize regional spatial patterns, and enhance ecosystem services and living environment in this urban agglomeration. Applying multi-stage remote sensing (RS) images, land use/cover change (LUCC) data, ecosystem services assessment data, and high-precision urban land-cover information, we reveal the regional land-cover characteristics of this new district as well as across the planned area of the entire BTH urban agglomeration. Corresponding ecological protection and management strategies are also proposed. Results indicated that built-up areas were rapidly expanding, leading to a continuous impervious surface at high density. Urban and impervious surface areas (ISAs) grew at rates 1.27 and 1.43 times higher than that in the 2000s, respectively, seriously affecting about 15% area of the sub-basins. Construction of XND mainly encompasses Xiongxian, Rongcheng, and Anxin counties, areas which predominantly comprise farmland, townships and rural settlements, water, and wetland ecosystems. The development and construction of XND should ease the non-capital functions of Beijing, as well as moderately control population and industrial growth. Thus, this development should be included within the national ‘sponge city’ construction pilot area in early planning stages, and reference should be made to international low-impact development modes in order to strengthen urban green infrastructural construction. Early stage planning based on the existing characteristics of the underlying surface should consider the construction of green ecological patches and ecological corridors between XND and the cities of Baoding, Beijing, and Tianjin. The proportion of impervious surfaces should not exceed 60%, while that of the core area should not exceed 70%. The development of XND needs to initiate the concept of ‘planning a city according to water resource amount’ and incorporate rainwater collection and recycling.

China’s investments, financial incentives and deductions in terms of ecological conservation are based at the county level. Therefore, the monitoring and assessment of the effects of ecological conservation at the county level is important to provide a scientific basis for the assessment of the ecological and environmental quality at the county scale. This paper quantitatively estimated the dynamics of high-quality ecosystems and vegetation coverage over the past 15 years, and their relationships with the number of ecological conservation programs at the county level were analyzed. Then, the effects of ecological conservation measures on ecological changes at the county level and their regional suitability were assessed and discussed. The results showed that counties with a percentage of high-quality ecosystems greater than 50% were primarily distributed in northeastern China, southern subtropical China and the southeastern Qinghai-Tibet Plateau, and those with a percentage lower than 20% were mostly distributed in northwestern China, the southwestern karst region and the North China Plain. In recent decades, ecological conservation has focused on ecologically fragile regions; more than five ecological conservation programs have been implemented in most counties of the Three River Source Region in Qinghai Province, southeastern Tibet, western Sichuan, the Qilian Mountains, southern Xinjiang and other western regions, while only one or zero have been implemented in the eastern coastal area of China. Over the past 15 years, the proportional area of high-quality ecosystems has increased in approximately 53% of counties. The vegetation coverage of counties in the Loess Plateau, Huang-Huai-Hai Plain, Beijing-Tianjin-Hebei (Jing-Jin-Ji), Sichuan-Guizhou-Chongqing, and Guangdong-Guangxi provincial-level areas has increased significantly. However, it decreased in northern Xinjiang, central Tibet, central and eastern Inner Mongolia, the Yangtze River Delta and other regions. The relationships between the numbers of ecological conservation programs and the indicators of ecosystem restoration response, such as high-quality ecosystem and vegetation coverage, do not show positive correlations. These results suggest that ecological conservation programs should be planned and implemented according to the distribution patterns of high-quality ecosystems and that restoration measures such as afforestation should follow natural principles and regional differentiation under the background of climate change.

This review summarizes the effects of vegetation on runoff and soil loss in three dimensions: vertical vegetation structures (aboveground vegetation cover, surface litter layer and underground roots), plant diversity, vegetation patterns and their scale characteristics. Quantitative relationships between vegetation factors with runoff and soil loss are described. A framework for describing relationships involving vegetation, erosion and scale is proposed. The relative importance of each vegetation dimension for various erosion processes changes across scales. With the development of erosion features (i.e., splash, interrill, rill and gully), the main factor of vertical vegetation structures in controlling runoff and soil loss changes from aboveground biomass to roots. Plant diversity levels are correlated with vertical vegetation structures and play a key role at small scales, while vegetation patterns also maintain a critical function across scales (i.e., patch, slope, catchment and basin/region). Several topics for future study are proposed in this review, such as to determine efficient vegetation architectures for ecological restoration, to consider the dynamics of vegetation patterns, and to identify the interactions involving the three dimensions of vegetation.

This study presents a soil and water integrated model (SWIM) and associated statistical analyses for the Huaihe River Basin (HRB) based on daily meteorological, river runoff, and water resource data encompassing the period between 1959 and 2015. The aim of this research is to quantitatively analyze the rate of contribution of upstream runoff to that of the midstream as well as the influence of climate change and human activities in this section of the river. Our goal is to explain why extreme precipitation is concentrated in the upper reaches of the HRB while floods tend to occur frequently in the middle reaches of this river basin. Results show that the rate of contribution of precipitation to runoff in the upper reaches of the HRB is significantly higher than temperature. Data show that the maximum contribution rate of upstream runoff to that of the midstream can be as high as 2.23%, while the contribution of temperature is just 0.38%. In contrast, the rate of contribution of human activities to runoff is 87.20% in the middle reaches of the HRB, while that due to climate change is 12.80%. Frequent flood disasters therefore occur in the middle reaches of the HRB because of the combined effects of extreme precipitation in the upper reaches and human activities in the middle sections.

There is a lack of simple ways to predict the vegetation responses to the East Asian Monsoon (EAM) variability in China due to the complexity of the monsoon system. In this study, we found the variation of the Western Pacific Subtropical High (WPSH), which is one of the major components of the EAM, has a profound influence on the vegetation growth in China. When the WPSH is located more to the west of its climate average, the eastern and northwestern parts experience increased yearly-averaged normalized difference vegetation index (NDVI) and gross primary productivity (GPP) by 0.3%-2.2%, and 0.2%-2.2%, respectively. In contrast, when the WPSH is located more to the east of its climate average, the above areas experience decreased yearly-averaged NDVI and GPP by 0.4% to 1.6%, and 1.3% to 4.5%, respectively. The WPSH serves as a major circulation index to predict the response of vegetation to monsoon.

The influence of monsoon climatic characteristics makes the tropics of China different from those of other parts of the world. Therefore, the location of the northern boundary of China’s tropical zone has been one of the most controversial issues in the study of comprehensive physical regionalisation in China. This paper introduces developments in the study of the northern boundary of China’s tropical zone, in which different scholars delimit the boundary with great differences based on different regionalisation objectives, indexes, and methods. The main divergence of opinion is found in different understandings of zonal vegetation, agricultural vegetation type, cropping systems, tropical soil type and tropical characteristics. In this study, we applied the GeoDetector model, which measures the spatial stratified heterogeneity, to validate the northern boundaries of the tropical zone delimited by six principal scholars. The results show that the mean q-statistic value of the higher latitude boundary delimited by Ren Mei’e is the largest (q=0.37), suggesting that, of the rival views, it best reflects the regional differences between China’s tropical and subtropical zones, but it is not necessarily suitable for guiding the development of tropical agriculture. The mean values of the q-statistics of Zheng Du’s line and Yu Xianfang’s line around the Leizhou Peninsula at a lower latitude were smaller, at 0.10 and 0.08 respectively, indicating that the regional differences were smaller than those of Ren Mei’e’s boundary. Against the background of global climate change, the climate itself is changing in fluctuation. It is, thus, worth our further research whether the northern boundary of the tropical zone should not be a fixed line but rather should fluctuate within a certain scope to reflect these changes.

Soil humic carbon is an important component of soil organic carbon (SOC) in terrestrial ecosystems. However, no study to date has investigated its geographical patterns and the main factors that influence it at a large scale, despite the fact that it is critical for exploring the influence of climate change on soil C storage and turnover. We measured levels of SOC, humic acid carbon (HAC), fulvic acid carbon (FAC), humin carbon (HUC), and extractable humus carbon (HEC) in the 0-10 cm soil layer in nine typical forests along the 3800-km North-South Transect of Eastern China (NSTEC) to elucidate the latitudinal patterns of soil humic carbon fractions and their main influencing factors. SOC, HAC, FAC, HUC, and HEC increased with increasing latitude (all P<0.001), and exhibited a general trend of tropical < subtropical < temperate. The ratios of humic C fractions to SOC were 9.48%-12.27% (HAC), 20.68%-29.31% (FAC), and 59.37%-61.38% (HUC). Climate, soil texture, and soil microbes jointly explained more than 90% of the latitudinal variation in SOC, HAC, FAC, HEC, and HUC, and interactive effects were important. These findings elucidate latitudinal patterns of soil humic C fractions in forests at a large scale, and may improve models of soil C turnover and storage.

Ecosystem services, which include water yield services, have been incorporated into decision processes of regional land use planning and sustainable development. Spatial pattern characteristics and identification of factors that influence water yield are the basis for decision making. However, there are limited studies on the driving mechanisms that affect the spatial heterogeneity of ecosystem services. In this study, we used the Hengduan Mountain region in southwest China, with obvious spatial heterogeneity, as the research site. The water yield module in the InVEST software was used to simulate the spatial distribution of water yield. Also, quantitative attribution analysis was conducted for various geomorphological and climatic zones in the Hengduan Mountain region by using the geographical detector method. Influencing factors, such as climate, topography, soil, vegetation type, and land use type and pattern, were taken into consideration for this analysis. Four key findings were obtained. First, water yield spatial heterogeneity is influenced most by climate-related factors, where precipitation and evapotranspiration are the dominant factors. Second, the relative importance of each impact factor to the water yield heterogeneity differs significantly by geomorphological and climatic zones. In flat areas, the influence of evapotranspiration is higher than that of precipitation. As relief increases, the importance of precipitation increases and eventually, it becomes the most influential factor. Evapotranspiration is the most influential factor in a plateau climate zone, while in the mid-subtropical zone, precipitation is the main controlling factor. Third, land use type is also an important driving force in flat areas. Thus, more attention should be paid to urbanization and land use planning, which involves land use changes, to mitigate the impact on water yield spatial pattern. The fourth finding was that a risk detector showed that Primarosol and Anthropogenic soil areas, shrub areas, and areas with slope <5° and 25°-35° should be recognized as water yield important zones, while the corresponding elevation values are different among different geomorphological and climatic zones. Therefore, the spatial heterogeneity and influencing factors in different zones should be fully considered while planning the maintenance and protection of water yield services in the Hengduan Mountain region.

Accumulation occurs widely in fluvial processes. Accurately accounting for the effects of previous water and sediment conditions on accumulation is essential for studying riverbed evolution. In this study, to reveal the physical mechanisms of accumulation, various geometric observations of both the upstream and downstream reaches of dams on several typical fluvial channels were analyzed. The changes in water and sediment conditions were defined as external disturbances. Assuming that the probability of an external disturbance conforms to a Poisson distribution, and that the response intensity induced by an individual disturbance decays exponentially over time, a mathematical description of the accumulation of internal responses to external disturbances is given. Furthermore, a corresponding theoretical model for simulating the spatiotemporal readjustments of characteristic river variables is proposed based on stochastic theory. The proposed models are then applied to investigate spatiotemporal readjustment in the upper and lower reaches of dams following their construction. The results indicate that temporally, the vertical, lateral, and overall readjustment rates of the reaches are relatively fast in the early period following dam construction but then decrease rapidly over time. Accumulated riverbed degradation, channel width, and sedimentation continuously increase until a new dynamic equilibrium is reached. These phenomena reflect the representative accumulation characteristics of fluvial processes. Spatially, the erosion intensities in downstream reaches decrease nonlinearly along the channel until eventually diminishing. The unbalanced spatial distribution of erosion intensity arises from the system response characterized by propagation in space but decay over time, which is characteristic of accumulation phenomena after disturbances. The results of the developed model show that the spatiotemporal readjustments of the studied cross-sections and channel reaches can be accurately described by the unified theoretical formula derived herein. The model predictions show good agreement with observed field data with determination coefficients of 0.92, 0.93, 0.76, and 0.95 for vertical, lateral, longitudinal, and overall readjustments, respectively. The proposed theoretical models account for both the accumulation characteristics of fluvial processes and their spatial distributions. In demonstrating the proposed approach, this study provides a theoretical basis and new calculation method for quantitatively describing the spatiotemporal readjustments of non-equilibrium fluvial channels following external disturbances.

International and domestic circumstances have led to new opportunities and higher requirements for the development of geographic science in China. In this paper, we propose a modified disciplinary structure for geographic science in China in the new era. Geographic science in China can be categorized into four secondary disciplines, i.e., integrated geography, physical geography, human geography, and information geography, according to the current situation and expected trends. The tertiary disciplines under each secondary discipline are nearly fully developed, and a few quaternary disciplines under the tertiary disciplines are widely accepted and used in China. We hope this new disciplinary structure can play a breakthrough role in improving the branches of geographic science, promoting the development of emerging disciplines under the framework of geographic science, and supporting national and international development strategies in the new era.

Physical geography, one of the branches of geography, is the basic discipline of geographic science. And it is the scientific foundation of ecology, environmental science and other related disciplines. Physical geography focuses on spatial characteristics, evolution and regional differentiation of the earth’s surface. In the new period of rapid development of social economy, and science and technology, physical geography is more closely and widely connected with human geography and, information geography. This paper analyzed the forming process of the physical geography, expressed sub-discipline structure of integrated physical geography, sectoral physical geography, human living-environment geography, and proposed the development strategy of physical geography and its sub-branch disciplines, key priority of development goals and directions in China.

Human geography is a discipline that studies the formation and evolution of the geographical distribution pattern of human activities. The main research objects of human geography focus on human activities and human-environment relationship. The scientific questions to be answered by human geography cover both natural science and social science, and thus it has distinctive interdisciplinary features. In China, human activities’ economic and social processes play an essential role in explaining the law in human geography discipline as human society development is approaching or has entered the post-industrialization stage. The logic and methods of social science have become important tools through which human geography’s changes in processes and patterns of human geography can be reasonably discussed and adequately understood. The research methodology of human geography shows integration characteristics between natural sciences and social sciences. The outcomes of human geography research reveal scientific laws in geographical distribution patterns and the evolution of human activities. It becomes one of the primary disciplines for both the national and local governments to manage and optimize spatial development and protection patterns. It has wide applications in spatial planning, regional strategy and policy-making, and the modernization of spatial governance. The unique feature in integrating academic research and policy-making applications provides human geography discipline in China a superiority of leading the world in the discipline. Besides integrated human geography, human geography in China has five subdisciplines: economic geography, urban geography, rural geography, socio-cultural geography and political geography. Each subdiscipline has priority and critical research fields and coordinates with the rest of the subdisciplines.

The advent of the information era has resulted in exceptional advances in geographic science. The domain of geographic science has expanded from traditional physical and human geography to physical, human, and information geography, resulting in the emergence of the field of information geography. Three subdisciplines have gradually formed, i.e., geographic remote sensing science, geographic information science, and geographic data science. With a view towards preparing a description of the disciplinary structure of geographic science for the “Development Strategy of Discipline and Frontier Research in China (2021-2035)”, this article summarizes the history, definition, and disciplinary structure of information geography. The strategic layout of the discipline, along with the goals and key directions of priority development fields, are also highlighted. The insights into this new discipline provided in this paper will promote the development and application of remote sensing and geographic information within the framework of geographic science, advancing the synthesis of geographic research and the integrated development of geographic science.

The rapid expansion of China’s urban agglomerations in recent decades has resulted in over-occupied ecological spaces and increased ecological pressure that are restricting healthy regional development. This paper examines the structure and characteristics of distribution of “production-living-ecological” spaces in five mega-urban agglomerations in China: Beijing-Tianjin-Hebei (BTH), the Yangtze River Delta (YRD), Guangdong-Hong Kong-Macao Greater Bay Area (GBA), Chengdu-Chongqing (CY), and the middle reaches of the Yangtze River (MYR). We analyze spatial and temporal variations in the ecological spaces and factors influencing them from 1990 to 2020, and examine the comprehensive ecological carrying capacity and status of ecological spaces in the past 30 years based on the available water resources, regulation of water and air quality, and leisure and recreation. The results show the following: (1) Urban agglomerations in different stages of formation and development represent varying area ratios of “ecological-production-living” spaces. The modes of expansion and evolution of the living spaces are dominated by multi-center combinations as well as the spatial structure of ecological spaces, including barrier, compact, discrete, and fully enveloping spaces. (2) From 1990 to 2020, the area occupied by living spaces in urban agglomerations continued to increase significantly while that of spaces for ecological production decreased. Except in the GBA, ecological spaces have exhibited a trend of increase in area, especially in the past 10 years. The area ratios and spatio-temporal variations in the “production-living-ecological” spaces indicate that the main functions of production and ecological spaces in mega-urban agglomerations have shifted from supply to regulation and culture, and reflect the transition from rapid urbanization to sustainable urbanization in China. (3) The comprehensive ecological carrying capacities of 78.6%, 73.1%, 54.5%, 56.3%, and 25.8% of cities in BTH, YRD, GBA, CY and MYR are severely overburdened. Water supply and the regulation of water quality are the main factors restricting the ecological carrying capacity of BTH and YRD while leisure and recreation services have hindered the capacities of GBA and CY. Policymakers thus need to pay attention to the conservation and rational layout of ecological spaces to reduce the ecological pressure in urban agglomerations. The work here can provide a scientific basis for the green and sustainable development of urban agglomerations as well as the optimized configuration of “production-living-ecological” spaces.

High-resolution mapping and monitoring of national land use/cover changes contribute significantly to the knowledge of the interaction between human activities and environmental changes. China’s Land Use/cover Dataset (CLUD) for 2020 and its dynamic changes in 2015-2020 were developed to extend the CLUD to over 30 years (i.e., the 1980s to 2020 at 5-year intervals) by integrating remote sensing big data and knowledge-based human-computer interaction interpretation methods. This integrating method for CLUD 2020 improved the efficiency of national land use/cover mapping and the accuracy of land use pattern change detection compared to earlier CLUD products, with an overall accuracy of 95%. The intensity of land use change decreased across China in 2015-2020 compared to 2010-2015, although both characteristics of its spatial changes were similar. The cropland area continued to shrink at national scale in 2015-2020, with two regional hotspots including the widespread conversions from dry land into paddy land in Northeast China and the coexistence of widespread land cultivation and cropland abandonment in Xinjiang of Northwest China. Built-up land area continued to expand in China, showing consistency between 2015-2020 and 2010-2015, in which hotspots transited from the surroundings of coastal megacities to the city surroundings of the central and western zones. For natural land, although the woodland and grassland decreased in 2015-2020, its magnitude expanded compared to 2010-2015. In comparison, the water body area in Qinghai-Tibet Plateau increased significantly under the continuous impact of climate change. These characteristics of land use change were closely related to the development strategy of the top-level design of the 13th Five-Year Plan (2016-2020) (e.g., ecological civilization construction and high-quality development).

Eco-environmental sustainability is the basis for sustainable development in ecologically fragile areas. Land consolidation plays an important role in coordinating human-land relationships and achieving economic growth and eco-environment protection. Taking the Loess Plateau as the study area, this paper diagnoses the associated eco-environmental problems and their chain effect. The research results show that the overall eco-environment of the region is still relatively fragile. An eco-environment multi-subject co-management model, a scale-differentiated management model, and an elements comprehensive management model are proposed to improve the eco-environmental management efficiency after implementing land consolidation in the plateau. This paper takes the Gully Land Consolidation Project in Baota district of Yan’an city in Shaanxi province as an example to illustrate the relationship between land consolidation and eco-environmental sustainability in the Loess Plateau. Policy implications for eco-environmental protection in the Loess Plateau are proposed.

The nexus exploration among land use/land cover change, ecosystem services and human well-being has been increasingly crucial in the context of Future Earth. However, the spatial heterogeneity and the entwining process among these three aspects have not yet been in-depth and systematically explored. Here we identified the spatiotemporal pattern of ecosystem services during the past 20 years in Yushu, the eco-fragile region and the centre of Qinghai-Tibet Plateau, as well as clarified its relationships with land use change and human well-being. We revealed that: (1) The structure of the ecosystem and land use in this area have been increasingly stable, and the ecological projects have exerted a positive impact. (2) Although the ecological environmental issues still need more attention, the ecosystem services of the area have been positively developing. (3) Derived by the ecosystem services increase, environmental projects and policies, the human well-beings of culture and education performed much better than other aspects. (4) It is crucial to carry out long-term ecological projects and increase educational investment for maintaining the stability of this ecologically fragile area. This study provides significant support for the regional ecological sustainability decision making, especially for the Qinghai-Tibet Plateau, the roof of the world.

Analyzing long term urban growth trends can provide valuable insights into a city’s future growth. This study employs LANDSAT satellite images from 1990, 2000, 2010 and 2019 to perform a spatiotemporal assessment and predict Ahmedabad’s urban growth. Land Use Land Change (LULC) maps developed using the Maximum Likelihood classifier produce four principal classes: Built-up, Vegetation, Water body, and “Others”. In between 1990-2019, the total built-up area expanded by 130%, 132 km² in 1990 to 305 km² in 2019. Rapid population growth is the chief contributor towards urban growth as the city added 3.9 km² of additional built-up area to accommodate every 100,000 new residents. Further, a Multi-Layer Perceptron - Markov Chain model (MLP-MC) predicts Ahmedabad’s urban expansion by 2030. Compared to 2019, the MLP-MC model predicts a 25% and 19% increase in Ahmedabad’s total urban area and population by 2030. Unaltered, these trends shall generate many socio-economic and environmental problems. Thus, future urban development policies must balance further development and environmental damage.

Accurate and rapid evaluation of the regional eco-environment is critical to policy formulation. The remote sensing ecological index (RSEI) model of the Guangxi Beibu Gulf Economic Zone (GBGEZ) during 2001-2020 was established and evaluated using four indices: dryness, wetness, greenness, and heat. This paper proposes an information granulation method for remote sensing based on the RSEI index value that uses granular computing. We found that: (1) From 2001 to 2020, the eco-environmental quality (EEQ) of GBGEZ tended to improve, and the spatial difference tended to expand. The regional spatial distribution of the eco-environment is primarily in the second-level and third-level areas, and the EEQ in the east and west is better than that in the middle. The contribution of greenness, wetness, and dryness to the improvement of EEQ in the study region increased year by year. (2) From 2001 to 2020, the order of the contribution of the EEQ index in the GBGEZ was dryness, wetness, greenness, and heat. (3) The social and economic activities in the study region had a certain inhibitory effect on the improvement of the EEQ.

In tropical regions, mangrove forests are located in the inter-tidal areas between land and sea, and are at risk from both freshwater and seawater floods. Using satellite-derived Normalized Difference Vegetation Index (NDVI) products, this study compared the differences in resistance and resilience of mangrove ecosystems to freshwater and seawater floods in Southeast Asia, and analyzed the spatial characteristics of the stability of mangrove ecosystems under floods in representative areas. Results show that mangroves tended to have lower mean resistance (28.24 vs. 37.32) and higher mean resilience (3.74 vs. 3.56) under freshwater floods, compared to seawater floods. Their resistance increased with the distance from rivers, such that the resistance of coastal areas to freshwater and seawater floods was lower than that of inland areas. These areas with lower resistance showed higher resilience compared to those with higher resistance. Damaged mangroves hardly fully recovered to their normal NDVI levels one year after seawater floods, especially in coastal areas. Although the occurrence of seawater floods was relatively rare in the past, it is likely to increase under more-intense climate extremes in the future, and the threat to the survival of mangroves may also increase. Thus, it is essential to evaluate the stability of mangrove ecosystems under floods.

Traditional trade routes that penetrate the natural barrier of the Himalayas are critical for connecting major Chinese and South Asian markets. Research on these trade routes can contribute significantly to facilitating the construction of the South Asian Corridor and enhancing trans-Himalayan connectivity. Combining historical literature, field surveys, and geographic information system (GIS) techniques, this study examined the spatial distribution characteristics and evolution process of the routes, focusing on transverse valleys of the Himalayan arc. The key findings were as follows. First, there are 21 traditional trade routes traversing the Himalayan region: six Sino-Nepalese routes, four Sino-Bhutanese routes, and eleven Sino-Indian routes. Second, the evolution of traditional trade routes has entailed five distinct phases: an incipient period (pre-7th century), formation (7th century-842 AD), development (842-1959), decline (1959-1962) and recovery (1962-present). Third, the incipient and formative developmental phases were prompted by the spread of Buddhism and the exchange of goods. The stability of local governments in Tibet and Central China and favourable border trade policies along with Britain’s colonial expansion and commercial interests stimulated further development of traditional trade routes. However, India’s strategic miscalculation and “Forward Policy” instigated the decline phase, while the demands of regional cooperation and development are currently the key drivers of the restoration and construction phase. Finally, to shelve disputes, promote cooperation and development, and enhance political mutual trust, governments should recover and construct traditional trade routes by replanning and constructing border trade markets, expanding border trade, developing pilgrimage and tourism, and strengthening cross-border cooperative research under global climate change.

This essay combines the Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS) nighttime light data and the Visible Infrared Imaging Radiometer Suite (VIIRS) nighttime light data into a “synthetic DMSP” dataset, from 1992 to 2020, to retrieve the spatio-temporal variations in energy-related carbon emissions in Xinjiang, China. Then, this paper analyzes several influencing factors for spatial differentiation of carbon emissions in Xinjiang with the application of geographical detector technique. Results reveal that (1) total carbon emissions continued to grow, while the growth rate slowed down in the past five years. (2) Large regional differences exist in total carbon emissions across various regions. Total carbon emissions of these regions in descending order are the northern slope of the Tianshan (Mountains) > the southern slope of the Tianshan > the three prefectures in southern Xinjiang > the northern part of Xinjiang. (3) Economic growth, population size, and energy consumption intensity are the most important factors of spatial differentiation of carbon emissions. The interaction between economic growth and population size as well as between economic growth and energy consumption intensity also enhances the explanatory power of carbon emissions’ spatial differentiation. This paper aims to help formulate differentiated carbon reduction targets and strategies for cities in different economic development stages and those with different carbon intensities so as to achieve the carbon peak goals in different steps.

Research on the carbon budget and zoning for carbon compensation in major functional zones (MFZs) is important for formulating strategies for low-carbon development for each functional zone, promoting the collaborative governance of the regional ecological environment, and achieving high-quality development. Such work can also contribute to achieving peak emissions and carbon neutrality. This paper constructs a theoretical framework for the carbon budget and carbon compensation from the perspective of the MFZ, uses 157 county-level units of the Beijing-Tianjin-Hebei urban agglomeration (BTHUA) as the study area, and introduces the concentration index, normalized revealed comparative advantage index, and Self Organizing Mapping-K-means (SOM-K-means) model to examine spatio-temporal variations in the carbon budget and carbon compensation zoning for the BTHUA from the perspective of MFZs. The authors propose a scheme for the spatial minimization of carbon emissions as oriented by low-carbon development. The results show that: (1) From 2000 to 2017, the carbon budget exhibited an upward trend of volatility, its centralization index was higher than the “warning line” of 0.4, and large regional differences in it were noted on the whole. (2) There were significant regional differences in the carbon budget, and carbon emissions exhibited a core-periphery spatial pattern, with a high-value center at Beijing-Tianjin-Tangshan that gradually decreased as it moved outward. However, the spatial pattern of carbon absorption tended to be stable, showing an inverted “U-shaped” pattern. It was high in the east, north, and west, and was low in the middle and the south. (3) The carbon budget was consistent with the strategic positioning of the MFZ, and the optimized development zone and key development zone were the main pressure-bearing areas for carbon emissions, while the key ecological functional zone was the dominant zone of carbon absorption. The difference in the centralization index of carbon absorption among the functional zones was smaller than that in the centralization index of carbon emissions. (4) There were 53 payment areas, 64 balanced areas, and 40 obtaining areas in the study area. Nine types of carbon compensation zones were finally formed in light of the strategic objectives of the MFZ, and directions and strategies for low-carbon development are proposed for each type. (5) It is important to strengthen research on the carbon balance and horizontal carbon compensation at a microscopic scale, enrich the theoretical framework of regional carbon compensation, integrate it into the carbon trading market, and explore diversified paths for achieving peak emissions and carbon neutrality.

Research on the spatio-temporal correlation between the intensity of human activities and the temperature of earth surfaces is of great significance in many aspects, including fully understanding the causes and mechanisms of climate change, actively adapting to climate change, pursuing rational development, and protecting the ecological environment. Taking the north slope of Tianshan Mountains, located in the arid area of northwestern China and extremely sensitive to climate change, as the research area, this study retrieves the surface temperature of the mountain based on MODIS data, while characterizing the intensity of human activities thereby data on the night light, population distribution and land use. The evolution characteristics of human activity intensity and surface temperature in the study area from 2000 to 2018 were analyzed, and the spatio-temporal correlation between them was further explored. It is found that: (1) The average human activity intensity (0.11) in the research area has kept relatively low since this century, and the overall trend has been slowly rising in a stepwise manner (0.0024·a^-1); in addition, the increase in human activity intensity has lagged behind that in construction land and population by 1-2 years. (2) The annual average surface temperature in the area is 7.18 ℃ with a pronounced growth. The rate of change (0.02 ℃·a^-1) is about 2.33 times that of the world. The striking boost in spring (0.068 ℃·a^-1) contributes the most to the overall warming trend. Spatially, the surface temperature is low in the south and high in the north, due to the prominent influence of the underlying surface characteristics, such as elevation and vegetation coverage. (3) The intensity of human activity and the surface temperature are remarkably positively correlated in the human activity areas there, showing a strong distribution in the east section and a weak one in the west section. The expression of its spatial differentiation and correlation is comprehensively affected by such factors as scopes of human activities, manifestations, and land-use changes. Vegetation-related human interventions, such as agriculture and forestry planting, urban greening, and afforestation, can effectively reduce the surface warming caused by human activities. This study not only puts forward new ideas to finely portray the intensity of human activities but also offers a scientific reference for regional human-land coordination and overall development.