With the rapid development of the Internet, Internet of things, and cloud computing technology, data with geographical location and time tag are accumulated in an explosive way, and this indicates that we are in the era of big spatiotemporal data. In addition to the typical "4V" characteristics, big spatiotemporal data also contain rich semantic information and dynamic spatiotemporal patterns. Although massive spatiotemporal data have promoted the evolvement of various cross-disciplinary studies, traditional methods of data processing and analysis would no longer meet the requirements of efficient storage and real-time analysis of such data. Therefore, it is of great importance to integrate big spatiotemporal data with high-performance computing/cloud computing. To address this problem, this article begins with the concept and origin of big spatiotemporal data, and introduces its unique characteristics. Then, the performance requirements generated by current big data applications are analyzed, and the status quo of the underlying hardware and software is summarized. Furthermore, the article comprehensively reviews parallel processing, analysis, and mining methods for big spatiotemporal data. Finally, we conclude with the challenges and opportunities of storage, management, and parallel processing analysis of big spatiotemporal data.
Transfer of carbon emissions embodied in inter-regional trade is an important reason that leads to inter-regional carbon leakage and inequity of regional carbon emission reduction responsibility, which has significant impact on global carbon emission pattern and carbon emission reduction effect. Therefore, studying the spatial-temporal evolution pattern and internal driving mechanism of carbon emission transfer and developing corresponding optimization policies are of great practical significance to improving the overall efficiency of carbon emission reduction and the comprehensive regional economic and ecological benefit, which has attracted extensive attention of scholars, and has gradually become one of the key issues of regional sustainable development and ecological economic research. This research systematically reviewed relevant studies about transfer of carbon emissions embodied in inter-regional trade in China and abroad, with special emphasis on summarizing the research progress and their application, as well as the future research directions of transfer of carbon emissions embodied in inter-regional trade. These directions include strengthening collaborative research between transfer of carbon emissions embodied in international and inter-provincial trade, revealing the dynamic driving forces and driving mechanism of transfer of carbon emissions embodied in inter-regional trade, and exploring innovative carbon emission transfer reduction mechanisms that are based on the shared production and consumption accounting principle.
The framework of sustainable livelihoods analysis (SLA) can be used for semi-urbanized farmers working in cities in order to promote urbanization in China and is suitable for research at household scale in China's western regions for improving sustainable rural development. This article first summarizes the concept and analytic framework of sustainable livelihoods, and from the comprehensive perspective of geography, develops a theoretical and analytic framework that is applicable to China's empirical study, based on the sustainable livelihoods of semi-urbanized farmers and sustainable rural development. Second, based on the program "Assessment of livelihoods status of semi-urbanized farmers, and obstructive factors and policy intervention of the transformation to urban residents" supported by the National Natural Science Foundation of China, the international and Chinese research on sustainable livelihoods, and the empirical research progress on the transformation from semi-urbanized farmers to urban residents and sustainable rural development in China, are introduced. Finally, this article presents the key themes of future research including integrated study of the transformation from semi-urbanized farmers to urban residents and sustainable rural development; comprehensive research of willingness and obstructive factors of transforming semi-urbanized farmers to urban residents; interactions of semi-urbanized farmers and rural development and the effect of transformation to urban residents; and integrated research of sustainable livelihoods and sustainable rural development.
Urbanization is essentially a geographical concentration of population and industry, and change of landscape patterns. The proportion of the urbanized population in China has increased to more than 50% during the recent decade. The rapid growth in such a short time period has not only led to an improvement of material wealth and a higher standard of living, but also caused severe environmental pollution, particularly the air pollution in many urbanized regions of China. In this research, multi-resolution remote sensing images, meteorological records, environmental monitoring data, and ground survey records were employed at multiple scales to understand the relationship between rapid urbanization and urban air quality, taking PM2.5 concentration as an indicator of air quality. The key findings are in the following three areas: (1) The spatial-temporal patterns of PM2.5 concentration in China; (2) The spatial-temporal patterns of the relationship between urban PM2.5 pollution and rural PM2.5 pollution in China's major cities; and (3) The linkage between urbanization and PM2.5 concentration at global, regional, city, and local scales. The results of this research also encourage different approaches to urbanization study in order to mitigate the negative impact caused by urban air pollution, both in China and in other rapidly developing mid- and low-income countries.
With the shift from Fordist to post-Fordist production, producer services have replaced manufacturing as the central activities in shaping regional economies and reorganizing the city systems of the "post-industrial" societies. Based on a critical evaluation of the existing literature, and an elaboration of the deliveries of the project" A study of the multi-scalar growth dynamics of producer services and its urbanization effects: from the political economy perspective" supported by the National Natural Science Foundation of China, this article discusses the applicability of the existing theories when they are used to understand the growth dynamics of producer services and its spatial effects in China. The main findings include: (1) producer services development shows similar pattern to that in the West, but exhibits its unique characteristics as well; (2) due to the distinctive relationships between the state and the market, the state and enterprises, and the central and local governments in China, existing theories and explanations, developed on the basis of the Western experiences, have yielded important insights but at the same time show limitations to account for the uneven growth of producer services in China; and (3) the dramatic expansion of producer services has led to the rapid growth of large cities and the emergence of mega-city regions, which have reshaped the economic space and reorganized the urban system in China. However, different from its Western counterparts, the spatial effects in China need to consider the impacts from the manufacturing industry.
Drawing from the key research results of the National Natural Science Foundation supported youth project "Study on industrial cluster restructuring mechanism from the perspective of local entrepreneurship—Case study in the Pearl River Delta, China" (No. 41301109), this article summarizes the literature and research results on the interacting relationships between local entrepreneurship and industrial clusters. It focuses on two aspects—the cluster environment that facilitates the emergence and growth of local entrepreneurship, and the agency and strategies of local entrepreneurs in industrial cluster restructuring. The primary research results are as follows. First, successful entrepreneurs in the clusters enhance the entrepreneurial intentions of others. Also, the embeddedness in personal relations with suppliers and customers has proven to exert significant impact on the locational preferences toward the clusters of origin, thus driving the localization of entrepreneurial activities. Second, cluster ecology and entrepreneurial ecosystem should become the focal point of study on the growth of entrepreneurial activities. The dynamic organizational relations with the parent companies are also important for the growth of spin-offs in the clusters. Meanwhile, local entrepreneurs active make and shape the clusters. In the mature industrial cluster in the core city of Guangzhou of the case study area—the Pearl River Delta, it is found that the new-generation start-ups could influence the spatial evolution of industrial cluster by their locational choice behaviors. In the periphery city, Jieyang, the institutional entrepreneurship carried out by the local entrepreneurs is an important way to upgrade and restructure the traditional industries. The interscalar strategies are applied by the local entrepreneurs to build up global pipelines, by which the resources and networks at different spatial scales are flexibly converged and leveraged. At the end of the article, future prospects with regard to the interacting relationship between local entrepreneurship and industrial cluster, both in terms of research context and methodology, has been discussed.
The humid region of Southeast China is one of the most prominent areas of environmental problems. Eutrophication of water bodies is a major problem that hampers the economic and social developments in the region. Especially in recent years, affected by government policies and market forces, the development of hilly and mountainous areas was intensified. Increasingly more virgin bamboo forests have been developed into economic land (such as tea garden). However, the land-use and land-cover change brings economic benefits as well as changes of soil pore structure and hydrological processes, which greatly affect the migration and transformation of nutrients in the soil. Within the National Natural Science Foundation of China (NSFC) supported project “Research on the physical mechanism and numerical simulation of hillslope soil hydrological processes in the hilly region of the Taihu Lake Basin” we made important progresses in the following three aspects: (1) spatiotemporal variations and influencing factors of hillslope soil moisture under different land use; (2) hillslope hydrological processes and water balance; and (3) influencing mechanism of hillslope soil hydrological processes. Despite these progresses, further research should focus on mechanisms of such processes, which would be of great importance for the control of eutrophication of the Taihu lake and non-point source pollution.
The Tibetan Plateau is surrounded by regions of the fastest growing atmospheric pollutants. The westerlies and the South Asian monsoon circulation transport the pollutants from Central Asia and South Asia to the inland of the Tibetan Plateau, which have important effects on the regional climate and environment. The concentration of black carbon in the snow and ice showed a clearly increasing trend during the recent few decades in the eastern and southern Tibetan Plateau, which might be associated with accelerated melting of snow and glaciers, and directly affected the hydrological processes on the plateau. However, the amount of transboundary transport of black carbon from South Asia is not clear and the knowledge of its impact on climate and cryosphere over the Tibetan Plateau is still limited. The development of atmospheric pollutants monitoring network on the Tibetan Plateau and the application of the high-resolution regional climate-atmospheric chemistry coupled model provide an opportunity for quantitative assessment of external transported pollutants and their climatic effects on the plateau. The project of “Simulation of transboundary transport of black carbon from South Asia and its impact on climate over the Tibetan Plateau,” which was supported by the National Natural Science Foundation of China, focused on the following three aspects: (1) Systematic assessment of the high-resolution regional climate-atmospheric chemistry coupled model performance in the simulation for the Tibetan Plateau. Based on the simulation of distribution, transportation, and deposition processes of black carbon over the Tibetan Plateau and surrounding regions, the climatic effects were investigated; (2) Examination of the mechanism of pollutant diffusion , and evaluation and comparison of the climatic effects induced by the anthropogenic and natural sources; (3) Quantitative estimation of the contribution of external pollutants outside the Tibetan Plateau. The results show that the black carbon from South Asia provided the highest contribution, which was 61.3% in the non-monsoon period and 19.4% in the monsoon season. This study revealed the effect of transboundary black carbon on the Tibetan Plateau, which may provide a scientific basis for improved management and prediction of the cryosphere and water resources in the core region of the Belt and Road initiative, and for police-making of climate change adaption and diplomatic negotiations.
This study focused on the Young Scientist Fund in geography supported by the National Natural Science Foundation of China (NSFC) from 1987 to 2016. Using bibliometrics analysis method, keywords frequency was analyzed and compared with the NSFC general projects in the same period by the four sub-disciplines of geography—physical geography, human geography, geographic information science, and environmental geography. Change of research characteristics and selected topics were also tracked. Seven representative keywords were chosen to study the change of topics in these cutting-edge research areas. The growth of young scholars was analyzed through their follow-up funding from the NSFC. This study shows that from 1987, the Young Scientist Fund project topics have been at the frontier of the study on the patterns and processes of the land surface environment and human economic system. Technological innovation was the main driving force of the Young Scientist Fund projects in geography. The research continued to be quantitative and innovative and the topics were gradually expanded to be integrative. The Young Scientist Fund has significantly promoted technological and theoretical innovations of geography in China.
The Tibetan Plateau (TP) is located in the southwest of China and central Asia, with a mean elevation higher than 4000 m and area of 3×106 km2. It is named "the roof of the world". The TP and surrounding areas together is also called "the Third Pole". The TP has 1200 lakes greater than 1 km2 in area, which accounts for approximately 50% of the total number and area of lakes in China. It is the sources of the Yellow River, the Yangtze River, the Indus, Ganges, Brahmaputra, Irrawaddy, Salween, and the Mekong, and therefor known as "Asia's water tower". In the past several decades, the TP experienced a faster warming than other regions in the world. The climate of the TP is also getting wetting. Lakes are indicators of climate change. The TP has the dense distribution of lakes with little disturbance of human activities. The utilization of multi-sensors’ data has provided a useful tool to monitor lake change in the remote TP. Several studies of lake changes have been conducted focusing on the following scientific questions: (1) how many lakes are on the TP and what are the spatial and temporal changes of the number, area, and abundance of these lakes? (2) the increased mass over the TP from glaciers or lakes? (3) under anthropogenic warming, how did the water and cryosphere cycles change on the two adjacent largest Plateaus in the world, the Tibetan and the Mongolian Plateaus, over the last four decades? and (4) how did the lake water storage and water balance change? These studies are of great significance to the understanding of the third pole of the world, the state of regional water resources and changes, and ecological civilization and ecological security construction. They also provide an important scientific basis for the planning of the third polar national park. The quantitative understanding of lake water balance and mechanisms and driving factors of lake change needs further work in the future.
Soil moisture is an important boundary condition of land-atmosphere interactions and plays a major role in the Earth's water and energy cycles. It directly affects the hydrological processes such as precipitation, runoff, infiltration, and evapotranspiration, and can provide direct information for flood and drought monitoring. Accompanied by the continuous development of space science and technology, especially the successful launching of the first L-band satellite mission of Soil Moisture and Ocean Salinity (SMOS) using passive microwave interference imaging technology, L-band passive microwave remote sensing has become a key tool in large-scale soil moisture mapping. New issues regarding L-band application including "detection and mitigation of radio frequency interference", "vegetation optical depth retrieval and vegetation effects correction", and "soil roughness parameterization" have been studied extensively. In this article, we summarize the latest research results of the project "Vegetation effects on soil moisture estimation using multi-angle observations at L-band" funded by the National Natural Science Foundation of China, and review the research progress made regarding the above issues. The future development of soil moisture microwave remote sensing is also prospected. The review of the research progress and the prospect of the cutting-edge issues will be helpful for the demonstration and implementation of China's future satellite missions, and promote the microwave remote sensing of soil moisture and application in eco-hydrology studies at the global and regional scales.
Incorporating the research results of the the National Natural Science Foundation supported project "Quantifying the effect of river water temperature on riverbed hydraulic conductivity of broad-shallow rivers in the arid area" (No. 41301025), this article summarizes the basic scientific issues and the current research progress in the field of water exchange between intermittent rivers and aquifers in arid areas of northwestern China. Riverbed at the lower reaches of rivers in the arid regions of northwestern China is shallow, wide, and sandy. Such riverbed experiences several dry/wet alternations and freezing-thawing process each year. Due to the influence of river temperature and river flow conditions, the riverbed as an important interface of river-aquifer systems exerts significant temporal and spatial variability, which has become a key issue in understanding surface water and groundwater exchange. Hyporheic zone hydrology, which focuses on river-aquifer interaction, is facing new opportunities and challenges under the current changing environment and rapidly developing interdisciplinary research.
This study focused on the Young Scientist Fund in geography supported by the National Natural Science Foundation of China (NSFC) from 1987 to 2016. Through the collection and analysis of information including applicants' profile, supporting institution, and follow-up funding, this study revealed the Young Scientist Fund support for the sub-disciplines of geography and their regional distribution characteristics. The gender, age, affiliation, and academic title of the project managers and their abilities to generate further funding from the NSFC were also analyzed. The 30 years' implementation of the Young Scientist Fund helped to bring up a great number of outstanding young scholars in various sub-disciplines of geography, which has laid a solid foundation for the cultivation of talents in geography in China.