Commuting is an important part of primary school students’ travel behavior, which has been concerned for a long time. We found that the commute-mode choice behavior of primary school students in the context of regional segmentation shows strong characteristics in space, but has not yet been considered in traditional research. To fill this gap, this study summarizes the commute-mode choices of primary school students with different characteristics based on the Beijing School Commute Survey. And the geographically weighted regression (GWR) model is built to analyze the zonal heterogeneity of the impact of personal characteristics, family factors and school factors on the primary school students’ commute- mode choices from a low-carbon perspective. The results demonstrate that the possibility of primary school students choosing low-carbon commuting modes is positively correlated with the grade, commuting time, commuting escort type and housing category, but is inversely related with the commuting distance and the distance from the school to the city center. The coefficient estimates of explanatory variables vary across regions. Finally, we put forward policy suggestions regarding promoting the low-carbon commuting structure, such as developing the urban slow traffic system, which serve as a reference for policymakers.

Promoting regional coordinated development strategy is one of the important strategies in the new period of China. Faced with the reality of unbalanced and insufficient regional development in China, it is objectively necessary to construct one or more main axes supporting the coordinated and balanced development of regions to become the identification line representing the pattern of coordinated regional development. The results show that the Bo-Tai line, the northwest-southeast axis connecting Bole of Xinjiang and Taipei of Taiwan, can be built into national development backbone line and regional balanced development line, just perpendicular to Hu Line. In 2016, the area of southwest half and northeast half of Bo-Tai Line accounts for 60%: 40%, while the population accounts for 45%: 55%, the economic aggregate accounts for 40%: 60%, the per capita GDP ratio accounts for 44%: 56%, the population density ratio accounts for 38%: 62%, the economic density ratio accounts for 32%: 68%, and the urbanization level ratio accounts for 48%: 52%. The main average indicators are gradually tending to balanced development pattern. Further analysis shows that Bo-Tai Line is a strategic shoulder pole connecting two core zones of “the Belt and Road”, and is the peaceful reunification line of China’s national tranquility and Taiwan’s return. Bo-Tai Line is also a solid line supported and connected by comprehensive transportation channels and a Pipa type symmetrical line for the development of cities and urban agglomerations. It is the backbone of the two-way opening up and the linkage development line between land and sea. It is also an important dividing line that promotes the coordinated development of the eastern, central and western regions, and addresses the imbalance and inadequacy of regional development. Bo-Tai Line plays an irreplaceable strategic role in promoting the coordinated and balanced regional development. It is suggested that the construction of Bo-Tai Line should be included in the national development strategy, and the development strategic plan of Bo-Tai Line should be formulated to fully release the multiple potential functions. We should build three strategic support points: the northwest endpoint, the central strategic node and the southeast endpoint; carry out a comprehensive scientific investigation of the Bo-Tai Line, and strengthen the scientific cognition and publicity; promote China’s development in a higher- level, higher-quality, more coordinated, safer and more civilized direction. Let Chinese know about the Bo-Tai Line, let the world know about the Bo-Tai Line, and let the Bo-Tai Line truly become the backbone of the great rejuvenation of the Chinese nation.

Associated with the rapid economic development of China, the level of urbanization is becoming a serious concern. Harbin, the capital city of Heilongjiang Province, China and one of the political, economic, cultural, and transportation centers of the northeastern region of China, has experienced rapid urbanization recently. To examine the spatial patterns of long-term urbanization and explore its driving forces, we employed the impervious surface fraction derived from remote sensing image as a primary indicator. Specifically, urban impervious surface information for the central city of Harbin in 1984, 1993, 2002, and 2010 was extracted from Landsat Thematic Mapper image using a Linear Spectral Mixture Analysis (LMSA). Then, the spatial and temporal variation characteristics and the driving factors of percent impervious surface area (ISA) changes were analyzed throughout this 26-year period (1984 to 2010). Analysis of results suggests that: (1) ISAs in the central city of Harbin constantly increased, particularly from 1993 to 2010, a rapid urbanization period; (2) the gravity center of impervious surface area in the central city was located in Nangang District in 1984, moving southeast from 1984 to 1993, northwest from 1993 to 2002, and continuing toward the southeast from 2002 to 2010; and (3) the urban growth of the central city can be characterized as edge-type growth.

The impact of reservoirs on downstream river channel change has been a scientific issue in fluvial geomorphology during the last few decades. However, it is still a difficult issue as to how to express quantitatively the channel adjustment in the Inner Mongolian reach of the Yellow River induced by the joint operation of upstream reservoirs. Based on the shape parameters of channel cross-sections at four gauging stations in this river reach over a flooding season in two periods, 1978-1982 and 2008-2012, the present work investigated the channel changes in terms of shape parameter change rate under the same controlling water level in each flooding season at the channel cross-sections. Results showed that most of the change rates of the parameters evidently increased over a flooding season in both periods. However, the change rate of each parameter at the cross-sections decreased evidently in the latter period, compared with the former period. At the same time, the distribution pattern of the change rate of the shape parameters along the cross-sections thus changed from a convex curve in the former period to an S-shaped curve in the latter period. The obvious decrease of the change rates is related to the joint operation of the Liujiaxia and Longyangxia reservoirs. The reservoirs stored a large volume of water and decreased the peak discharge and maximum velocity in the flooding season; as a result, the erosion ability of the flood decreased accordingly. With the joint operation of the large reservoirs, the Inner Mongolian channel shrunk markedly. Therefore, the channel will present the possibility of an extreme flood in the future. Consequently, it is reasonable to adjust the function of the reservoirs in future. The total water and sediment discharges and the peak discharge in flooding seasons should be effectively controlled. Continuous shrinkage of the channel can thus be avoided and it can be ready for a potential extreme flood.

The Qinling Mountain Range (QMR) spans a large region in China and is an important area of hominin activities. Many Paleolithic sites are found in Bahe, South Luohe, and Hanjiang river valleys in the northern, eastern, and southern part of the range, respectively. The Danjiang River valley acts as a channel connecting these valleys and stretches from the north to the south of the QMR. The previous dating of the Paleolithic sites in the Danjiang valley mainly relied on geomorphologic comparison, stratigraphic correlation, fossil characteristics, and Paleolithic artifacts, indicating a lack of absolute data. In this study, we conducted a detailed geochronological investigation of the entire valley, and selected an ideal site—the Miaokou profile. Based on the identification of the loess-paleosol sequences, optically stimulated luminescence, and magnetostratigraphy, the Paleolithic artifacts of the Miaokou site located within the S5 and S6 layers of the profile belong to ~0.6-0.7 Ma. This suggests that the Paleolithic site is an old site in the Danjiang River valley, and this period also witnessed a rapid increase in the number of hominin sites during the Middle Pleistocene. Combining our results with previous reports across the QMR, we propose that the Danjiang River valley might have been a corridor for hominin migration, and is worthy of further investigation.

Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain. The area of saline land increased from 4627 km² in 1980 to 5416 km² in 2000, and then decreased to 5198 km² in 2015. The transformation between saline land and other land covers happened mainly before 2000, and saline land had transformation relationship mainly with cropland, grassland, and water body. From 1979 to 2007, groundwater depth fluctuated to increase and was mainly deeper than 3.3 m. Spatially, the area of the region where groundwater depth was deeper than 3.3 m increased from 46.7% in 1980 to 84% in 2000, while the area of the region almost occupied the whole region after 2000. Precipitation and evaporation changed little, while runoff decreased substantially. Shallow groundwater, change of cropland, grassland, and water body induced from human activities and decrease of runoff and increase of irrigation and water transfer from outer basin were the main reasons for land salinization before 2000. After 2000, groundwater with relatively great depth could not exert great influence on land salinization. Protection of grassland and wetland prevented the increase of the area of saline land.

It is significant to estimate terrestrial net primary productivity (NPP) accurately not only for global change research, but also for natural resources management to achieve sustainable development. Remote sensing data can describe spatial distribution of plant resources better. So, in this paper an NPP model based on remote sensing data and climate data is developed. And 1km resolution AVHRR NDVI data are used to estimate the spatial distribution and seasonal change of NPP in China. The results show that NPP estimated using remote sensing data are more close to truth. Total annual NPP in China is 2.645×10⁹ tC. The spatial distribution of NPP in China is mainly affected by precipitation and has the trend of decreasing from southeast to northwest.

This study analyzes the spatial patterns and driving forces of housing prices in China using a 2,872-county dataset of housing prices in 2014. Multiple theoretical perspectives on housing demand, supply, and market, are combined to establish a housing price model to explore the impact of land prices on housing prices. The relative impacts of land prices on housing prices at different administrative levels are then analyzed using the geographical detector technique. Finally, the influencing mechanism of land prices on housing prices is discussed. The main conclusions are as follows. (1) Housing prices have a pyramid-ranked distribution in China, where higher housing prices are linked to smaller urban populations. (2) Land prices are the primary driver of housing prices, and their impacts on housing prices vary over different administrative levels. To be specific, the effect of land prices is the strongest in the urban districts of provincial capital cities. (3) The internal influence mechanisms for land prices driving housing prices are: topographic factors, urban construction level, the agglomeration degree of high-quality public service resources, and the tertiary industrial development level. The urban land supply plan (supply policies) is the intrinsic driver that determines land prices in cities; through supply and demand, cost, and market mechanisms, land prices then impact housing prices.

The core objective of rural vitalization is to systemically establish a coupling pattern of various rural development elements including population, land and industry. As one of the prerequisites, land resources is required to be optimally allocated via land consolidation. Consequently, land consolidation contributes greatly to population agglomeration, industrial development and resources support under the context of combating rural decline. Based on the key elements affecting rural development, this paper elaborates the connotation of rural vitalization and land consolidation in the new era as well as their relationships. Furthermore, the paper analyzes the alternative paths for achieving rural vitalization via land consolidation, and discusses the future directions of land consolidation and rural vitalization. The conclusions are drawn as follows: (1) To cope with the loss and decline of the intrinsic elements in rural areas, rural vitalization is a development strategy aimed at realizing economic, political, cultural and ecological rejuvenation in rural area by reshaping socio-economic morphology and spatial pattern in rural territory. (2) From the perspective of rural vitalization, land consolidation is endowed with new connotation, which should not only target at activating the key elements of rural development, but also place emphasis on coordinating material space and spirit core as well as integrating the restructuring of the physical space and the rural governance system. (3) Land consolidation should be compatible with regional natural conditions and the current stage of socio-economic development. According to the principle of regional planning and classification strategy, the appropriate models and paths should be adopted to promote the benign interactions of population, land and industry based on engineering techniques and ecological means. (4) Under the background of national strategy of rural vitalization, it is necessary to reshape the value orientation of land consolidation based on a scientific understanding of urban-rural relations and rural territorial functions, coordinate land consolidation planning and rural vitalization planning under the unified spatial planning system, and explore the new model combining land consolidation and multifunctional agriculture.

Changes in rice production in Southern China are crucial to national food security. This study employed Landsat images to map the distributions of paddy rice-cropping systems in Southern China in 1990 and 2015. The impact of rice multiple cropping index changes on grain production capacity was then evaluated. Three important results were obtained for the 1990 to 2015 study period. First, the multiple cropping index for rice decreased from 148.3% to 129.3%, and 253.16×10 ⁴ ha of land area was converted from double-cropping to single-cropping rice, termed “double to single”. The area with the most dramatic changes is in the Middle-Lower Yangtze Plain. The rice-cropping system distribution in Southern China showed a change from north to south with double-cropping rice shrinking and single-cropping rice expanding. Second, the “double to single” conversion led to a reduction of 6.1% and 2.6% in rice and grain production, respectively. Hunan and Jiangxi Provinces, located in the main rice producing areas, and Zhejiang, which has shown better economic development, exhibited large reductions in rice production due to the “double to single” conversion, all exceeding 13%. Third, the grain production capacity of converted “double to single” paddy fields is equivalent to that of 223.3 × 10 ⁴ ha of newly reclaimed cultivated land, which is 54% of the total newly cultivated land reclaimed through the 2001-2015 land consolidation project. It is also 1.7 times the target goal for newly cultivated land in the national land consolidation plan for 2016-2020. Making full use of the converted “double to single” paddy fields can save 167.44 billion yuan in newly reclaimed cultivated land costs. Therefore, instead of pursuing low-quality new arable land, it is better to make full use of the existing high-quality arable land. Based on these results, the government should change the assessment method for cultivated land balance, and incorporate the sown area increased by improving the multiple cropping index into the cultivated land compensation indicator.

Accurately diagnosing and assessing complicated spatial linkages at various scales has become a crucial strategy for enhancing the efficacy of urban government policies and initiatives in the modern era. There is still room for improvement in identifying spatial scale disparities and coupling linkages in cities, although the standard research paradigm on urban sustainability has produced numerous positive outcomes. To advance urban sustainability research from the perspective of spatial coupling, this study used cluster and cross-tabulation analyses for considering urban sustainable development patterns from the requirements of both development scale and spatial accuracy. Subsequently, the spatial unit coupling relationship between district and street scales was explored. Our findings indicated significant scale dependence in the spatial divergence between the built environment sustainability levels of streets and the economic, social, and environmental sustainability levels of districts. The implication is that significant differences exist in the built environment levels of various sustainable development type districts. The scale effect of the spatial coupling relationship influences urban planning and the transition of sustainable development. Maintaining reasonable population density and maximizing the structure and quality of social public resources supply are priorities for streets with the highest habitat sustainability that are located in low-growth type districts. Priority should be given to population deconcentration for high habitat sustainable streets located in synergistic development type districts to increase the level of public service protection. Supporting facilities should be added to medium sustainable streets in low-growth areas to increase the mix of land use, which should encourage additional production activity concentration, thereby fostering overall economic strength. Further, increasing the accessibility of local public service facilities for low and medium sustainable streets located in ecologically biased areas should be prioritized, but a green and low-carbon orientation should be maintained during building.

A typical requirement in digital society is the rapid distribution and effective application of digital products. Geographical data bases are far more complex than other ones in that both attribute and spatial data have to be stored and handled under the same framework. On the other hand, the number of end users of digital cartographic data is explosively increasing, ranging from professional map makers to vehicle drivers and individual tourists. Thus arises a question: how can a data supplier give the “best” service to each user? In nature it involves such difficult problems as cartographic generalization and map simplification. In this paper, the author argues that the visual knowledge or perception experience can be effectively exploited and used to guide the process of data simplification. We have developed a prototype system with a subset of the vector road database covering Munich city.

This study presented a quantitative comparison of cockpit and doline karst by examining the numbers and characteristics of typical types of landform entities that are developed in Guilin (Guangxi, China), La Alianza (PR, USA), Avalton (KY, USA), and Oolitic (IN, USA). Five types of landform entities were defined: isolated hill (IH), clustered hills (CHs), isolated sinkhole (IS), clustered sinkholes (CSs), and clustered hills with sinkholes (CHSs). An algorithm was developed to automatically identify these types of landform entities by examining the contour lines on topographic maps of two cockpit karst areas (Guilin and La Alianza) and two doline karst areas (Oolitic and Avalton). Within each specific study area, the CHSs is the least developed type yet with a larger size and higher relief. The IH and IS entities are smaller in size, lower in relief, and outnumber their clustered counterparts. The total numbers of these types of entities are quite different in cockpit and doline karst areas. Doline karst is characterized by more negative (IS and CSs) than positive (IH and IHs) landforms and vice versa for cockpit karst. For example, the Guilin study area has 1192 positive landform entities in total, which occupy 9.81% of the total study area. It has only 622 negative landform entities occupying only 3.91% of the total study area. By contrast, the doline karst in Oolitic has 130 negative while only 10 positive landform entities. The positive and negative landforms in Oolitic occupy 12.68% and 2.61% of the total study area, respectively. Furthermore, average relief and slope of the landform entities are much higher and steeper in the cockpit karst than the doline karst areas. For instance, the average slope of CHs in Alvaton is 3.90 degrees while it is 19.78 degrees in La Alianza. The average relief of CSs is 4.07 m and 34.29 m in Oolitic and Guilin respectively. Such a difference within a specific area or between the cockpit and doline karst may reveal different controls on the development of karst landscape.

Under China’s innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis to analyze spatiotemporal differences of venture capital in the Beijing-Tianjin-Hebei urban agglomeration for the period 2005-2015. A gravity model and panel data regression model are used to reveal the influencing factors on spatiotemporal differences in venture capital in the region. This study finds that there is a certain cyclical fluctuation and uneven differentiation in the venture capital network in the Beijing-Tianjin-Hebei urban agglomeration in terms of total investment, and that the three centers of venture capital (Beijing, Shijiazhuang and Tangshan) have a stimulatory effect on surrounding cities; flows of venture capital between cities display certain networking rules, but they are slow to develop and strongly centripetal; there is a strong positive correlation between levels of information infrastructure development and economic development and venture capital investment; and places with relatively underdeveloped financial environments and service industries are less able to apply the fruits of innovation and entrepreneurship and to attract funds. This study can act as a reference for the Beijing-Tianjin-Hebei urban agglomeration in building a world-class super urban agglomeration with the best innovation capabilities in China.

Based on daily average temperatures and observation data from 74 meteorological stations in Chinese oases, we calculate five-day (pentad) average temperature ≤0℃ for the start and end pentad as well as pentads of cold period using linear regression analysis, nonparametric Mann-Kendall tests, the Morlet wavelet power spectrum, and correlation analysis. We also analyze spatial and temporal variations and their effects on the start and end pentad as well as pentads of cold period in Chinese oases. Results show that over the last 55 years, the start pentad of cold period has been postponed while the end pentad has been advanced. Overall, the pentads have gradually shortened over time at trend rates that are 0.3 p/10a, -0.27 p/10a, and -0.58 p/10a, respectively. Spatial differences are significant, especially for the Qaidam Basin oasis where the start pentad is the earliest, the end pentad is the latest, and the trend of change is most obvious. Mutation points for the start and end pentad as well as pentads of cold period were observed in 1990, 1998, and 1994, respectively. Of these, the start pentad and pentads of cold period show a periodic cycle, related to atmospheric circulation and El Nino events, while the end pentad exhibits a periodic cycle, related to solar activity. The Tibetan Plateau index (TPI), the Asian polar vortex area index (APVAI), and carbon dioxide emissions (CDE) are the main factors affecting cold period in the study area, whereas the South Asian summer monsoon (SASM) index exerts the greatest effect on the Qaidam Basin oasis. The start and end pentad as well as pentads of cold period increase in concert with latitude, longitude, and altitude; in response to these changes, the start pentad is advanced, the end pentad is postponed, and pentads of cold period are gradually extended. Results show that change in latitude is most significant. Overall, the start and end pentad as well as pentads of cold period show clear responses to regional warming, but there are different effects on each.

Based on dynastic period division and AMS¹⁴C dating performed on the sedimen-tary layers at Zhongba and Yuxi sites, and also the analysis of Na, Ca and Mg of 201 sedi-mentary samples from Zhongba site and that of Ca and Na in 47 sedimentary samples from Yuxi by using an inductively coupled plasma–mass spectrometry (ICP), we found that there were 35 time periods when the contents of Ca and Na were reversely correlated, i.e. when-ever the content of Ca was the highest, the content of Na was the lowest, and vice versa. Among them, there were 21 time periods when the content of Ca was the highest, and Na was the lowest, indicating that there were about 21 prosperous periods of ancient salt pro-duction at Zhongba site since 3000BC. Other 14 time periods with the peak values of Na while the low values of Ca indicate 14 declined periods of salt production at Zhongba site since 3000BC. The conclusion obtained from the reverse relationship between Ca and Na contents in this paper is consistent with that “the salt production at Zhongba site started in the new stone age, developed in the Xia and Shang dynasties, reached at the heyday in periods from the Western Zhou to the Han Dynasties, maintained stable to develop in the Tang and the Song dynasties, and gradually declined after the Song Dynasty because the sea salt were conveyed into Sichuan region, however, still had production in the 1970s–1980s”, educed from archeological exploration. All the above mentioned results indicate that there is a re-verse relationship obviously between the contents of Na and Ca in sediments at Zhongba site for ancient salt production, which can

Lunar landforms are the results of geological and geomorphic processes on the lunar surface. It is very important to identify the types of lunar landforms. Geomorphology is the scientific study of the origin and evolution of morphological landforms on planetary surfaces. Elevation and relief amplitude are the most commonly used geomorphic indices in geomorphological classification studies. Previous studies have determined the elevation classification criteria of the lunar surface. In this paper, we focus on the classification criteria of the topographic relief amplitude of the lunar surface. To estimate the optimal window for calculating the relief amplitude of the lunar surface, we use the mean change-point method based on LOLA (Lunar Orbiter Laser Altimeter) Digital Elevation Model (DEM) data and SLDEM2015 DEM data combining observations from LOLA and SELenological and Engineering Explorer Terrain Camera (SELENE TC). The classification criterion of the lunar surface relief amplitude is then determined according to the statistical analysis of basic lunar landforms. Taking the topographic relief amplitudes of 100 m, 200 m, 300 m, 700 m, 1500 m and 2500 m as thresholds, the lunar surface is divided into seven geomorphic types, including minor microrelief plains (< 100 m), minor microrelief platforms [100 m, 200 m), microrelief landforms [200 m, 300 m), small relief landforms [300 m, 700 m), medium relief landforms [700 m, 1500 m), large relief landforms [1500 m, 2500 m) and extremely large relief landforms (≥ 2500 m). The minor microrelief plains are mainly distributed in the maria and the basalt filled floors of craters and basins, while the minor microrelief platforms are mainly in the transition regions between the maria and highlands. The microrelief landforms are mainly located in regions with relatively high topography, such as wrinkle ridges and sinuous rilles in the mare. The small relief landforms are mainly scattered in the central peak and floor fractures of craters. The medium relief landforms are mainly distributed in the transition regions between crater floors and crater walls, between crater walls and crater rims, between basin floors and basin walls, and between basin walls and basin rims. Large and extremely large relief landforms are mainly found along crater walls and basin walls. The classification criteria determination for assessing lunar surface relief amplitude described in this paper can provide important references for the construction of digital lunar surface geomorphology classification schemes.

Arbuscular mycorrhizal fungi (AMF) are universally mutualistic symbionts that colonize the fine roots of most vascular plants. However, the biogeographical patterns and driving factors of AMF diversity of plant roots in grasslands are not well investigated. In this study, we used high-throughput sequencing techniques and bioinformatics to evaluate the AMF richness of 333 individual plant roots in 21 natural grassland ecosystems in northern China, including the Loess Plateau (LP), the Mongolian Plateau (MP), and the Tibetan Plateau (TP). The AMF richness showed a significant parabolic trend with increasing longitude. In regional situations, the AMF richness in the grasslands of the MP (60.4 ± 1.47) was significantly higher than those of the LP (46.4 ± 1.43) and TP (44.3 ± 1.64). Plant traits (including plant families, genera, and functional groups) explained the most variation in the AMF richness across China’s grasslands, followed by energy and water; soil properties had the least effects. The results showed the biogeographical patterns of the AMF richness and the underlying dominant factors, providing synthetic data compilation and analyses in the AMF diversity in China’s grasslands.

Knowledge innovation is a key component of urban innovation function and an important basis for modern urban development. Combining the multidisciplinary research of knowledge innovation, this paper constructs a measurement framework of urban knowledge innovation function from the perspective of urban geography and analyzes its spatial pattern and influencing factors. The conclusions are as follows: (1) The function of urban knowledge innovation refers to the tasks and roles it undertakes in the process of knowledge creation, knowledge dissemination and knowledge application, which is based on the internal knowledge stock and external practice conditions to meet the needs of human survival and development in the new era. The measurement dimensions include functional scale, functional intensity, functional scale, and functional vitality. (2) The development level of knowledge innovation functions in Chinese cities is uneven, and the cities with outstanding knowledge innovation functions are mainly concentrated in the eastern coastal areas and a few developed areas in the central and western regions, forming the diamond-shaped knowledge innovation structure with the Beijing-Tianjin, the Yangtze River Delta, the Pearl River Delta, Shaanxi-Chengdu-Chongqing as the four vertices and central Wuhan and Hefei as the center. According to the Jenks natural breakpoint method, it is divided into national-level, regional-level, local-level and knowledge-innovative development cities. (3) The spatial differentiation characteristics of urban knowledge innovation function are simultaneously affected by various natural and human factors. Among them, economic environment, opening environment, and cultural environment have the strongest interactive explanatory power with other factors, and are the dominant factors affecting the city’s knowledge innovation function. In the future, China should fully considers the status and characteristics of the city’s own knowledge economy development with corresponding policies and measures suitable for the development of the city’s knowledge economy, and strengthen the dominant position of human and social factors in the constructing the city’s knowledge innovation function.

With the objectives to acquire the fundamental data of the territorial resource, understand the impacts of human activities on the land use and cover patterns and evaluate the potential of the future exploitation, an intensive land cover classification with an accuracy of 93% has been completed for North Ningxia by remote sensing technique based on the adoption of a combination method composed of texture training, maximum likelihood classification and post-processing such as re-allocation and aggregation. This classification result was incorporated with the contemporaneous socio-economic and meteorological data for cross-sectional regression modelling to reveal the spatial determinants of the land cover patterns and understand the human-environmental relationships. A tentative evaluation on the potential of soil exploitation in the near future was carried out in combination with our land use and cover change detection results aiming at supplying some useful references for the central and local governments in their sustainable land use planning.

The pattern for utilization of rural space is closely related to rural transformation development (RTD). The problem of rural space utilization is an important manifestation of the uncoordinated relationship between land use patterns and rural development status during a transformation period. Considering the rural space utilization issue, this article seeks to analyze the interaction mechanisms between land use transition (LUT) and rural spatial governance and then build a rural spatial governance analysis framework based on LUT. Also, the paper explores the internal relationship between rural spatial governance and rural vitalization and discusses the research prospective of the interaction. The study found that: (1) Rural space utilization has systemic problems such as limited development space, ill-defined ownership and poor organization, which have become important obstacles for rural development. (2) The uncoordinated relationship between LUT and RTD is an important reason for the dilemma surrounding rural space utilization. (3) The LUT provides a basis for determining the timing of rural spatial governance, specifying spatial governance objectives, and clarifying rural spatial governance methods. (4) The construction of a comprehensive analysis framework of “matter-ownership-organization” of rural space based on the LUT has created conditions for the orderly promotion of rural spatial governance. (5) Rural spatial governance which facilitates the integration of urban-rural development is an important foundation for rural vitalization. (6) Interaction analysis of LUT, RTD and rural spatial governance is conducive to facilitating research on the operational mechanism of rural regional systems and to expanding the research field of rural geography.

Global climate change has become a major concern worldwide. The spatio-temporal characteristics of net ecosystem productivity (NEP), which represents carbon sequestration capacity and directly describes the qualitative and quantitative characteristics of carbon sources/sinks (C sources/sinks), are crucial for increasing C sinks and reducing C sources. In this study, field sampling data, remote sensing data, and ground meteorological observation data were used to estimate the net primary productivity (NPP) in the Inner Mongolia grassland ecosystem (IMGE) from 2001 to 2012 using a light use efficiency model. The spatio-temporal distribution of the NEP in the IMGE was then determined by estimating the NPP and soil respiration from 2001 to 2012. This research also investigated the response of the NPP and NEP to the main climatic variables at the spatial and temporal scales from 2001 to 2012. The results showed that most of the grassland area in Inner Mongolia has functioned as a C sink since 2001 and that the annual carbon sequestration rate amounts to 0.046 Pg C/a. The total net C sink of the IMGE over the 12-year research period reached 0.557 Pg C. The carbon sink area accounted for 60.28% of the total grassland area and the sequestered 0.692 Pg C, whereas the C source area accounted for 39.72% of the total grassland area and released 0.135 Pg C. The NPP and NEP of the IMGE were more significantly correlated with precipitation than with temperature, showing great potential for C sequestration.

With so many sports becoming increasingly popular, sports have come to play an important role in promoting the process of globalization and formatting the world city network (WCN). Previous studies have constructed the WCN based on the distribution of international sport federations (ISFs) and the sites of international sport events (ISEs), but there is still a lack of systematic research on the intercity connections caused by ISEs. Taking three most recent Olympic Games as cases, this paper explores intercity connections and WCN based on ISEs. The results show that (1) the Olympic WCN has city nodes around the world except in Antarctica, and the number and activity values of the cities in host countries may increase intensively during the Olympic Games. (2) A hierarchical city system with four tiers (global central cities, specialized central cities, national central cities and specialized cities) is formed by the intercity connections caused by the Olympic Games. (3) The WCN based on the Olympic Games, is made up of many subnetworks, while many differences occur due to the diverse decisions made by the Organizing Committee for the Olympic Games (OCOG), host cities or even host countries in the events associated with sponsorship activity and publicity activity. This study not only broadens the relevant fields of sports culture-oriented WCN research but also explores the instability of the WCN, which makes it an effective reference for WCN research based on ISEs.

Climate change is manifesting rapidly in the form of fires, droughts, floods, resource scarcity, and species loss, and remains a global risk. Owing to the disaster risk management, there is a need to determine the Dead Fuel Index (DFI) threshold of the fire occurrence area and analyze the spatio-temporal variation of DFI to apply prevention measures efficiently and facilitate sustainable fire risk management. This study used the MODIS Burned Area Monthly L3 (MCD64A1), Landsat Global Burned Area (BA) products, and MODIS Surface Reflectance 8-Day L3 (MOD09A1) data from 2001 to 2020 to calculate the values of the DFI in the study area before the occurrence of fire. The results showed that: (1) The inversion of the meadow steppe DFI values in the fire area was distributed in the range of 14-26, and the fire rate was the highest in the range of 20-22. The inversion of the typical steppe DFI values in the fire area was distributed in the range of 12-26, and the fire rate was the highest in the range of 16-22. (2) Areas with high fire DFI values included Khalkhgol, Matad, Erdenetsagaan, Bayandun, Gurvanzagal, Dashbalbar in Mongolia, and scattered areas of the Greater Khingan Mountains (forest edge meadow steppe area), East and West Ujumqin Banner, and Xin Barag Right Banner. The highest fire probability of fire occurred during October and April. (3) The DFI values were sensitive to changes in altitude. The results of this study may provide useful information on surface energy balance, grassland carbon storage, soil moisture, grassland health, land desertification, and grazing in the study area, especially for fire risk management.

Quantifying the contributions of climate change and human activities to ecosystem evapotranspiration (ET) and gross primary productivity (GPP) changes is important for adaptation assessment and sustainable development. Spatiotemporal patterns of ET and GPP were estimated from 2000 to 2014 over North China Plain (NCP) with a physical and remote sensing-based model. The contributions of climate change and human activities to ET and GPP trends were separated and quantified by the first difference de-trending method and multivariate regression. Results showed that annual ET and GPP increased weakly, with climate change and human activities contributing 0.188 mm yr^-2 and 0.466 mm yr^-2 to ET trend of 0.654 mm yr^-2, and -1.321 g C m^-2 yr^-2 and 7.542 g C m^-2 yr^-2 to GPP trend of 6.221 g C m^-2 yr^-2, respectively. In cropland, the increasing trends mainly occurred in wheat growing stage; the contributions of climate change to wheat and maize were both negative. Precipitation and sunshine duration were the major climatic factors regulating ET and GPP trends. It is concluded that human activities are the main drivers to the long term tendencies of water consumption and gross primary productivity in the NCP.

Based on remote sensing data of the Yangtze River Delta (YRD) in the years of 1991, 2001 and 2008, the paper built an index system of land use potential restraint factors in YRD, according to geological condition, terrain condition, water area, natural reserve area and basic farmland, and evaluated construction land potential based on the platform of GIS spatial analysis model. The results showed that: (1) the construction land increased rapidly since 1991 and reached 24,951.21 km² in 2008, or 21.27% of the total area. Among all the cities in the YRD, Shanghai took the greatest percentage, followed by Jiangsu and Zhejiang. Spatially, areas where government departments are located became the growth center of construction land. Prefecture-level cities were the fastest growth region and the changing trend showed circle layered characteristics and significant increase with Shanghai and Suzhou as the core. (2) The higher the quality of construction land potentials (CLP), the smaller the number of CLP units. High sensitive area accounted for the largest percentage (40.14%) among all types of constraint regions and this was followed by medium sensitive region (31.53%) of the whole region. (3) The comprehensive CLP in the YRD was 24,989.65 km², or 21.76% of the total YRD. The land use potential showed spatial distribution imbalance. CLP of Zhejiang was obviously larger than that of Jiangsu. CLP was insufficient in regional central city. Moreover, CLP in the YRD formed a circle layered spatial pattern that increasingly expanded centered in prefecture-level cities. Low potential area expanded from north to south. High potential area was mainly located in south YRD. Areas with zero potential in the YRD formed a northwest-southeast “Y-shaped” spatial pattern in north Hangzhou Bay. (4) CLP per capita in YRD was 0.045 ha/person and also unevenly distributed. Some 25.57% of the study units at county level nearly had no construction land and 8.24% of the units had CLP per capita below the national average level. CLP per capita in less than 25% of the county-level units was larger than the YRD average level, which were mainly located in Zhejiang. Therefore, research on the construction potential area in YRD was favorable for analysis of the development status and potential space of this region under the background of rapid urbanization and industrialization.

Comprehensive information on geographic patterns of leaf morphological traits in Chinese forests is still scarce. To explore the spatial patterns of leaf traits, we investigated leaf area (LA), leaf thickness (LT), specific leaf area (SLA), and leaf dry matter content (LDMC) across 847 species from nine typical forests along the North-South Transect of Eastern China (NSTEC) between July and August 2013, and also calculated the community weighted means (CWM) of leaf traits by determining the relative dominance of each species. Our results showed that, for all species, the means (± SE) of LA, LT, SLA, and LDMC were 2860.01 ± 135.37 mm², 0.17 ± 0.003 mm, 20.15 ± 0.43 m² kg^-1, and 316.73 ± 3.81 mg g^-1, respectively. Furthermore, latitudinal variation in leaf traits differed at the species and community levels. Generally, at the species level, SLA increased and LDMC decreased as latitude increased, whereas no clear latitudinal trends among LA or LT were found, which could be the result of shifts in plant functional types. When scaling up to the community level, more significant spatial patterns of leaf traits were observed (R² = 0.46-0.71), driven by climate and soil N content. These results provided synthetic data compilation and analyses to better parameterize complex ecological models in the future, and emphasized the importance of scaling-up when studying the biogeographic patterns of plant traits.

In the past few decades, economic globalization has driven rapid growth of cross-border trade and a new international division of labor, leading to increasing inter-country embodied carbon flows. Multi-region input-output (MRIO) analysis is used to identify embodied carbon flows between major world regions, including seven regions along the Belt and Road (BR), and the spatial distribution of production- and consumption-based carbon intensities. The results show that current embodied carbon flows are virtually all from BR regions to developed countries, with more than 95% of world net embodied carbon exports coming from BR regions. Consumption in the United States and European Union countries induce about 30% of the carbon emissions in most BR regions, indicating that the former bear a high proportion of consumers’ responsibility for the carbon emitted in the latter. For this reason, measuring environmental responsibilities from consumption rather than a production-based perspective is more equitable, while developing countries should be given a louder voice in the construction through dialogue and cooperation, in part in the context of the Belt and Road Initiative, of an inclusive global climate governance system.

Geomorphometry, the science of digital terrain analysis (DTA), is an important focus of research in both geomorphology and geographical information science (GIS). Given that 70% of China is mountainous, geomorphological research is popular among Chinese scholars, and the development of GIS over the last 30 years has led to significant advances in geomorphometric research. In this paper, we review Chinese progress in geomorphometry based on the published literature. There are three major areas of progress: digital terrain modelling methods, DTA methods, and applications of digital terrain models (DTMs). First, traditional vector- and raster-based terrain modelling methods, including the assessment of uncertainty, have received widespread attention. New terrain modelling methods such as unified raster and vector, high-fidelity, and real-time dynamic geographical scene modelling have also attracted research attention and are now a major focus of digital terrain modelling research. Second, in addition to the popular DTA methods based on topographical derivatives, geomorphological features, and hydrological factors extracted from DTMs, DTA methods have been extended to include analyses of the structure of underlying strata, ocean surface features and even socioeconomic spatial structures. Third, DTMs have been applied to fields including global climate change, analysis of various typical regions, lunar surface and other related fields. Clearly, Chinese scholars have made significant progress in geomorphometry. Chinese scholars have had the greatest international impact in areas including high-fidelity digital terrain modelling and DTM-based regional geomorphological analysis, particularly in the Loess Plateau and the Tibetan Plateau regions.

The operation of large-scale reservoirs have modified water and sediment transport processes, resulting in adjustments to the river topography and water levels. The polynomial fitting method was applied to analyze the variation characteristics of water levels under different water discharge values in the Jingjiang reach of the Yangtze River from 1991-2016. The segregation variable method was used to estimate the contributions of the varied riverbed evaluation, the downstream-controlled water level, and the comprehensive roughness on the altered water level at an identical flow. We find that low water levels in the Jingjiang reach of the Yangtze River from 1991-2016 are characterized by a significant downward trend, which has intensified since 2009. Riverbed scouring has been the dominate factor causing the reduced low water level while increased roughness alleviated this reduction. From 1991-2016, there was first a decrease followed by an increase in the high water level. The variation characteristic in terms of the “high flood discharge at a high water level” before 2003 transformed into a “middle flood discharge at a high water level” since 2009. The increased comprehensive roughness was the main reason for the increased high water level, where river scouring alleviated this rise. For navigation conditions and flood control, intensified riverbed scouring of the sandy reaches downstream from dams enhanced the effects that the downstream water level has on the upstream water level. This has led to an insufficient water depth in the reaches below the dams, which should receive immediate attention. The altered variation characteristics of the high water level have also increased the flood pressure in the middle reaches of the Yangtze River.