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  • ZHOU Jie, JU Nengpan, ZHANG Yan, TIAN Huabing, HE Chaoyang
    Online available: 2025-05-15
    Abstract:Debris flow disasters, characterized by their frequent occurrence and high destructiveness, are significantly constrained by the inadequate real-time performance and elevated false alarm rates inherent in conventional monitoring methodologies. This critical limitation underscores the urgent need to develop highly efficient and precise intelligent detection techniques to substantially enhance early warning capabilities. To address the challenges of poor real-time performance and high false alarm rates in traditional debris flow monitoring systems, an enhanced YOLOv8m-GCSlide model is proposed based on the YOLOv8 framework. The global context attention module (GCNet) is integrated into the backbone network to strengthen spatial dependency modeling of dynamic fluid boundaries in complex terrains, while a sliding loss function (SlideLoss) is designed to dynamically adjust classification thresholds and mitigate sample imbalance. Knowledge distillation is further applied to compress the model, resulting in a lightweight variant (YOLOv8n-GCSlide) with reduced computational complexity. A multi-source video dataset is constructed using publicly available resources, where frames are extracted at 0.25-second intervals to balance feature retention and training efficiency. Data augmentation techniques, including random cropping, rotation, scaling, Gaussian blur, and color jittering, are employed to enhance generalization, supplemented by negative samples (e.g., dry riverbeds, landslides) to reduce false positives. Experimental results demonstrate that the optimized model achieves 94.6%(+2.0%) detection accuracy, 88.0% recall, 95.9% mean average precision, and an inference speed of 244.1 FPS, outperforming mainstream lightweight models such as SwinTransformer and MobileNet variants. After compression, the model parameters are reduced by 88.1%, with a distilled version maintaining 94.6%(+1.2%) accuracy and 88.0% (+0.7%) recall while achieving 244.1 FPS. Field validation in Sedongpu Gully, a high-risk debris flow region, confirms practical applicability: under complex environmental interference, the model attains 82.3% recall, 4.2% false positive rate, and 240.6 FPS processing speed. The integration of global attention mechanisms and taskspecific loss functions is shown to effectively capture dynamic motion features and suppress environmental noise. Additionally, model compression techniques ensure a balance between accuracy and computational efficiency, enabling edge deployment for real-time disaster warnings. This approach provides a robust technical foundation for intelligent geological hazard monitoring systems, emphasizing high precision, low latency, and adaptability to resource-constrained scenarios.
  • DU Xinru, LU Zi, DING Jianghui
    Online available: 2025-05-14
    Abstract: This paper aims to develop solutions for two significant and urgent problems in air transportation. One is the contradiction between the bustle of main airspaces and the huge aviation industry development demand, and the other is the contradiction between the large-scale developments of aviation industry and the traditional aviation management mode. The application of continuous trajectory data and the development of airflow micro-temporal analysis technology have created the conditions for operational efficiency assessment in corridors-in-the-sky to meet the challenges of some key issues such as the detection of full process detection and economic effect measurement. This paper presents a framework for assessing the operational performance of air passenger flow including temporal variation and spatial state, internal composition relationship and external connection relationship. Based on the delayed trajectory data of flights and taking time delay cost as a feedback variable, a series of indicators of delay number, delay duration, delay occurrence area and delay propensity index are concluded, and the operational performance of air passenger flow of major corridors-in-the-sky in Sino-U.S. is compared. There are the following findings: the constraints on operational performance occur mainly in the maintenance phase of the airspace, where delayed trajectory clusters lead to longer Euclidean distances and narrower flight path activity, resulting in increased flight path rigidity or invariability and then reduced opportunities for multi-path selection. In addition, the limited over-flow capacity of the corridors-in-the-sky in China is likely to cause delays in delay-intensive segments and downstream delay contagion, and also leads to the accumulation of terminal delays. On this basis, this paper expected to play a certain role in improving the construction of corridors-in-the-sky, improving the utilization rate of airspace, promoting the reform of airspace configuration and also will bring a comprehensive technical support for optimisation of dynamic airspace and the implementation of the national strategic plan of “Airspace Channel”.
  • GUO Linghui, YAN Jingjing, LUO Yuanyuan, XU Zimeng, GAO Jiangbo, WU Shaohong, FENG Qianfeng
    Online available: 2025-05-13
    Abstract:The North China region is one of the important grain production bases in China, while climatic drought is the main natural disaster affecting agricultural production, always resulting in immense lose for the agriculture. Hence, exploring the spatiotemporal evolution and formation mechanism of drought in North China is an important basis for a quantitative understanding of drought mechanisms as well as the scientific prevention and control of drought disaster risk, insuring regional and even national food security. based on SPEI-3 and largescale circulation data, this study investigated systematically the spatial variation pattern of drought events during the growth period of winter wheat and its potential influencing factors from the perspective of key growth stages, by combining run length theory, cluster analysis and wavelet transform coherence methods. The results showed that the climate during the growth period of winter wheat in North China from 1961 to 2021 has been becoming moist, especially from the booting stage to the maturity stage, with humidification in Hebei, Henan, and Shandong provinces, and drying tendency in Shanxi province. Henan Province and its surrounding areas were characterized by larger frequency and shorter duration of drought were in during the growth period of winter wheat, while droughts in Hebei Province and northern Shandong Province were characterized by long duration, low frequency and high severity. The spatial clustering patterns of drought event appeared different during individual growth period. SPEI-3 was strongly related to circulation factors during the entire growth period, emergence-tillering period, overwintering-jointing period, and booting-maturity period of winter wheat, with critical influencing factor of TNA, PNA, AO, and NINO34, respectively. The results of this study could provide regional specific valuable insights for agricultural drought resistance and disaster reduction decision-making in North China.
  • LI Xiaolan, ZHANG Hongsheng
    Online available: 2025-05-13
    Abstract:Dust emission process is the primary component in the dust cycle. Quantitative and complete description of the dust emission process is the basis for accurate simulation and prediction of dust aerosols. Dust emission process is highly non-steady and non-uniform and has intermittent feature, also known as intermittent dust emission. How to accurately describe the intermittent dust emission process is an important scientific issue in current dust research. Based on the research results of dust emission processes from field experiment, wind tunnel experiment and numerical simulation during the past two decades, the development of observation techniques for intermittent dust emission process based on high-frequency measurements and its occurrence conditions and identification methods using relevant turbulence thresholds and intermittent factors are reviewed. The impact mechanism of boundary-layer turbulence structure and their thermal and dynamic-thermal effects during intermittent dust emission process are summarized. The development of dust emission parameterization schemes under different dust-emission mechanisms, particularly the methods to establish intermittent dust emission schemes via introducing gust variations, intermittent factors, or probability density distributions of turbulence parameters are discussed. Finally, some suggestions are put forward for the problems existing in current dust emission research and future potential research directions.
  • HUANG Jianping, LIAN Xinbo, WANG Rui, WANG Danfeng
    Online available: 2025-03-29
    Abstract:The ongoing public health challenges posed by climate change cannot be ignored. Monitoring and early warning of pathogenic microorganisms and infectious diseases is a key precondition for preventing large-scale public health crisis and biosecurity risks. However, insufficient research and attention have been paid to the monitoring and early warning of pathogenic microorganism spread due to climate and environmental change, especially for the health threats caused by airborne pathogenic microorganisms. By analyzing the necessity and foresight of monitoring and early warning of pathogenic microorganisms, the key scientific problems in the field of monitoring and early warning of pathogenic microorganisms and infectious diseases are summarized, and the research basis and conditions of monitoring and early warning methods and applications of infectious diseases are sorted out. It includes the impact of climate change on pathogenic microorganisms in the atmosphere, the monitoring of pathogenic microorganisms in the atmosphere, and the prediction model and system of infectious diseases. The urgent need to strengthen the basic research on the formation, source analysis, environmental evolution and transmission mechanism of atmospheric pathogenic microorganisms in the future is discussed in this paper. The research and development of high-precision real-time monitoring technology for pathogenic microorganisms in the atmosphere should be accelerated, and national and provincial pathogenic microorganisms and infectious disease monitoring networks should be established through multi-departmental cooperation. Multiple dimensions such as artificial intelligence, big data and genomics should be used as entry points to enhance data collection and sharing. Priority should be given to the development of prediction and early warning of infectious diseases to provide scientific and technological support for infectious disease monitoring and early warning and biosecurity risk prevention under the climate crisis.
  • HUA Wenjian, FENG Huiting, CUI Yazhu, HU Yuhan
    Online available: 2025-03-29
    Abstract: In the summer of 2022, the Yangtze River Basin experienced unprecedented heatwaves, which aroused wide attention from the scientific community. Affected by over a month of record-breaking high temperature and drought, this extreme event has not only caused increasingly serious losses to humans, economic and environment, but exacerbated food insecurity and hindered sustainable development. Therefore, a more comprehensive understanding of the extreme heat in the Yangtze River Basin in the summer of 2022 is essential for understanding the causes of changes in extreme events under the context of global warming, and for recognizing the impacts of human activities and natural variability, as well as evaluating the potential climate risks. The study firstly reviews the main characteristics, formation mechanisms and causes of the extreme high temperature in the Yangtze River Basin in the summer of 2022, and further summarizes the research progress of the 2022 summertime heat extremes in the last three years. Results show that 2022 summertime high temperature in the Yangtze River Basin is a rare extreme heat event. The occurrence of this event was mainly caused by the atmospheric circulation anomalies due to the western Pacific subtropical High and the South Asian High, the triple La Nina, the Atlantic and Indian SST forcing, and the land-atmosphere feedback (e.g., soil moisture and air temperature). In addition to the contribution of natural variability, human activities are also the main factors influencing the heat extremes. Without anthropogenic forcing, it is almost impossible to happen. Such rare extreme heatwaves are projected to become much more common under global warming. Finally, this study discusses the relevant research points and problems of the extreme high temperature.
  • WEI Feng, WU Baoxiang, XIE Wenxin
    Online available: 2025-03-29
    Abstract:Hydrocarbon compounds in Herbaceous plants play an important role for assessing ecological and environmental changes in cold and arid areas at high altitudes. The alkanes and olefins in Festuca brachyphylla Schult. & Schult. f. from high altitude cold and arid area, Tianshan mountain were analyzed by means of organic geochemical methods, for learning their geochemical characteristics and response to the environment. Results show that, for alkanes in, the carbon numbers range from C16 to C29. The average carbon chain length (ACLAlk) are 17.91~24.49, and the main peak carbon are C16, C18 and C29. For olefins, there are carbon number ranges of C16~C31, the average carbon chain length (ACLOle) of 22.19~26.23,and the main peak carbon mainly C16 and C20. Together, alkanes and olefins in the herb plants exhibit that their overall contents of low carbon number components (carbon number of alkane and olefins are ≤23 and <27, respectively) are relatively higher, and there are even-to-odd predominance in lower carbon number components but odd-to-even predominance in the higher, significantly. By comparing the hot and humid, drought environments, and others, it is found that Festuca brachyphylla Schult. & Schult. f. from high altitude cold and arid area, Tianshan mountain have unique geochemical characteristics, such as with higher content of low carbon alkanes and olefins, lower average carbon chain length (ACL) value, and differentiations of odd-even predominance (OEP) index between of the lower carbon hydrocarbons and of the highers. The average carbon chain length of olefin (ACLOle) value of herbaceous plants with good water supplement are larger, relatively. There is a close positive correlation between the average carbon chain length of alkanes (ACLAlk) and olefins (ACLOle) in Festuca brachyphylla Schult. & Schult. f.. The results obtained provide an important reference for understanding the ecological adaptation mechanism of herbaceous plants in high altitude cold and arid areas and evaluating the impact of environmental changes on ecosystems.
  • XIA Liuqing, ZHANG Min, WU Yuxiang
    Online available: 2025-03-27
    Abstract:The relative abundance of tricyclic terpanes has significant indicative value for revealing organic matter sources, depositional environments, and thermal evolution stages. While traditional coal-measure source rocks typically exhibit low tricyclic terpanes content, anomalously high abundances of tricyclic terpanes (relative to hopanes) have been detected in coal-measure source rocks from the Ordos and Tarim Basins. Therefore, an indepth investigation of their distribution patterns, compositional characteristics, and formation mechanisms is of substantial significance. This study employed conventional geochemical analysis methods and gas chromatography-mass spectrometry (GC-MS) to systematically analyze molecular geochemical characteristics of 30 coal-measure source rock samples from the study area. The research demonstrates that tricyclic terpanes in coal-measure source rocks present two distinct abundance patterns: low abundance tricyclic terpanes (ΣTT/C30H <2) and high abundance tricyclic terpanes (ΣTT/C30H>2). The low abundance tricyclic terpane samples exhibit a C19-21TT decreasing distribution pattern, formed in freshwater oxidizing environments, with hydrocarbongenerating parent material primarily derived from higher plants, and at low thermal maturity. The high abundance tricyclic terpane samples display distribution patterns with C23TT or C21TT as the dominant peak, formed in saline, sulfur-rich depositional environments, with hydrocarbon-generating parent material mainly sourced from bacteria and lower aquatic organisms, reaching mature to highly mature thermal evolution stages. Correlation analysis between maturity, depositional environment, and parent material input parameters with Σ TT/C30H values reveals that parameters characterizing depositional environment and hydrocarbon-generating parent material show more significant correlation with tricyclic terpane abundance. The results indicate that brackish, high-sulfur coal-forming environments and increased input of secondary products generated by microbial transformation of higher plants in hydrocarbon-generating parent material are the primary controlling factors for high abundance tricyclic terpanes in coal-measure source rock extracts, while thermal maturity serves as a secondary influencing factor. The molecular composition and formation mechanisms of high-abundance tricyclic terpanes in coal-measure source rocks offer critical molecular geochemical evidence for recognizing coal-forming environments, identifying hydrocarbon-generating organic matter, and assessing thermal maturity, thereby providing theoretical and practical guidance for coal-measure hydrocarbon exploration.
  • XIE Simin, DU Zhiheng, WANG Lei, YANG Fangping, CUI Hao, TAO Changlian, YANG Jiao, WU Tonghua, XIAO Cunde
    Online available: 2025-03-27
    Abstract: Subsea permafrost, formed by the inundation of terrestrial permafrost due to the sea-level variations during the glacial-interglacial cycles, is mainly distributed across the Arctic continental shelf. However, there is a large uncertainty in its distribution extent (approximately 1~2.7 million square kilometers). Subsea permafrost is considered a significant carbon reservoir in the Earth system, which stores vast amounts of organic carbon (OC) and methane (CH4) gas. With global warming and rising temperatures of Arctic Ocean waters, subsea permafrost is undergoing rapid degradation, which may exacerbate carbon release risks. Consequently, the subsea permafrost plays a significant role in influencing the global carbon cycle and climate change. The large CH4 emissions into the atmosphere have been observed in the East Siberian subsea permafrost region. However, the rates of subsea permafrost degradation, the magnitude of carbon reservoirs and gas release are still not clear. In particular, due to the rapid Arctic warming, the northward expansion and intensification of the North Atlantic Current which exacerbates the Atlantification of the Arctic Ocean, and dramatic increases in human disturbance, the climate risk would increase by the accelerated emission of CH4 from Arctic subsea permafrost. These variations will influence the human sustainability in the future. This paper systematically summarizes the spatial distribution, degradation rates, and carbon storage in Arctic subsea permafrost. The applications of methods for CH4 monitoring in the subsea permafrost were reviewed, including the fixed-point observations, aerial surveys, and remote sensing. Furthermore, this paper discusses factors influencing CH4 emissions, highlights the importance of studying the characteristics of Arctic subsea permafrost and its carbon cycle for global climate change, and identifies current challenges and suggests future research directions.
  • LI Chenhao, LIANG Wenjun, HU Hui, DONG Wenjie, LÜJianhua
    Online available: 2025-02-03
    Abstract:As the climate crisis intensifies, the Earth & Climate System Model as a key numerical simulation tool for predicting and responding to future climate change has become increasingly important. The Coupled Model Intercomparison Project (CMIP) aims to promote model development and deepen scientific understanding of the Earth’s climate system, and has become a core platform for international model exchange and application. This paper summarizes China’s participation in the sixth CMIP (CMIP6), and statistically analyzes the citation situation, research overview and characteristics of Chinese models in CMIP6-related studies. The results show that Chinese models are widely used and have a far-reaching impact, but lack highly cited achievements. It is necessary to integrate resources and focus on developing representative models. In addition, this paper briefly introduces the seventh Coupled Model Intercomparison Project (CMIP7) under preparation, and summarizes the opportunities and challenges China faces in model development. The application prospects of Chinese models are broad, but there is still room for improvement. China should continue to increase investment in research and development, maintain international competitiveness, and be well-prepared for continued in-depth participation in global climate change governance.
  • WU Jiakun, HU Xiaofei, PAN Baotian, CAO Xilin, WEN Zhenling, SUN Qiang, LI Menghao, ZHAO Qiming
    Online available: 2025-02-03
    Abstract:The Qilian Shan, the youngest mountain range formed by the northward expansion of the Tibetan Plateau, plays a crucial role in understanding the plateau’s expansion processes, uplift mechanisms, and the evolution of orogenic belts. Drainage system evolution responds rapidly to mountain uplift, making the study of drainage development and evolution a critical approach for investigating the uplift and expansion of the Qilian Shan. Based on chronological and provenance studies of geomorphic records, including erosion surfaces, river terraces, wind gaps and ancient river channels, and Cenozoic sedimentary strata, the current research on drainage system evolution in the Qilian Shan has yielded the following findings and insights: ① The formation and evolution of the upper reaches of the Yellow River in the eastern Qilian Shan involve a process of drainage reorganization driven by tectonic uplift or climate change, characterized by headward erosion and river capture; ② Research on river terraces in the Shiyang River and Heihe River basins of the northern Qilian Shan, as well as in the Lanzhou Basin of the eastern Qilian Shan, indicates climate change and tectonic uplift independently govern the timing (transitions between glacial and interglacial periods, and interglacial periods) and extent of river incision; Since the Holocene, terrace formation has been primarily driven by climate change, with river incision occurred during warm and humid periods; ③ River terraces reliably record the evolution processes of major tributaries of the Yellow River in the eastern Qilian Shan, including the Huangshui River (flow reversal) and the Datong River (river capture); ④ Study of chronology, provenance, and paleohydrology of Cenozoic sedimentary strata in the Yumu Shan of the northern Qilian Shan, as well as the Wulan and Chacha basins of the southern Qilian Shan, has reliably reconstructed the regional drainage evolution history, highlighting the significant potential of sedimentary strata for reconstructing reliable and detailed record of drainage evolution. Simultaneously, numerous critical issues remain unresolved, necessitating further investigation. Future research is expected to prioritize and emphasize in-depth studies on geomorphic surface and sediments dating, the integration of multi-source methods for provenance analysis, continuous exploration of geomorphic features, as well as advancements in numerical simulations and simulation modeling studies.
  • GUAN Min, ZHANG Yong, LI Yun, YAO Yixin, CHANG Yuan, SHAO Yikai
    Online available: 2025-02-02
    Abstract: During more than 50 years of continuous research and technological innovation, China's Fengyun Meteorological Satellite System has got significant achievement. 21 Fengyun satellites have been launched. Currently, 9 of them are operating stably in orbit, forming a comprehensive observation system that includes geostationary orbit and sun synchronous polar orbit satellites. By reviewing the development history and current status of Fengyun meteorological satellites and remote sensing instruments, the effectiveness of ground segments in data reception, processing, and operation, as well as the construction and service of application systems, the technical capabilities of Fengyun meteorological satellites, their ground segments and application systems have been analyzed comprehensively. Through comparative analysis with major countries around the world in terms of meteorological satellite network observation, remote sensing instrument technology, and ground segment operation capabilities, it is found that Fengyun Meteorological Satellites not only have a complete orbit layout and remote sensing instrument configuration, but its remote sensing instrument detection capability has reached the international advanced level, although some performance indicators still have room for improvement. The ground segments have established an efficient data reception, processing, and service process, with advanced data pre-processing technology and sub-pixel level geolocation accuracy. The radiometric calibration accuracy is 3% in the visible band and 0.2 K in the infrared band. In addition, the Fengyun Meteorological Satellite System has established a comprehensive and complete quantitative product system for atmospheric, land, marine, and space weather, and has established a radiation correction field for Chinese remote sensing satellites, and carried out authenticity verification of remote sensing products. Fengyun satellite data has been widely used in various fields such as weather forecasting, climate change research, ecological environment monitoring, and natural disaster warning, and its application level is constantly improving. In the future, the Fengyun meteorological satellite observation system aims to evolve towards establishing a hybrid-architecture space observation system, achieving comprehensive and precise perception of observation elements, enabling intelligent and efficient operation of satellite-ground systems, integrating emerging technologies in data processing, expanding remote sensing application scenarios, and fostering international cooperation and sharing.
  • ZHANG Jingyong
    Online available: 2024-12-19
    A new framework for studies of climate change projections and disaster risks oriented towards carbon neutrality was built up, based on a division method of positive emissions period-net zero period-net negative period. Focusing on main Belt and Road regions, future mean and extreme climate change projections and disaster risks oriented towards carbon neutrality were systematically addressed under SSP1-1.9 and SSP1-2.6 sustainable development pathways. It is projected that over global carbon neutrality or net-zero periods, climate change will exhibit new characteristics and patterns, and disaster risks will undergo new changes over the main Belt and Road regions. The newly developed framework provides a new scheme for climate change projections and disaster risks assessment. It is proposed that the seventh assessment report of Intergovernmental Panel on Climate Change (IPCC) and the other future assessment report on climate change should include climate change projections and disaster risks assessment oriented towards carbon neutrality, which can provide new scientific knowledge for jointly dealing with climate change and achieving sustainable development. In addition, the role and application of Artificial Intelligence in future climate change projections and climate disasters assessment are discussed.
  • ZHAO Qiang, ZHENG Yongguang, JING Yu, FENG Dian, LIU Juju
    Online available: 2024-12-13
    Abstract:Short-duration heavy precipitation is one type of the most important severe convective disaster weather in China, which is prone to cause urban waterlogging and secondary geological disasters such as mountain torrents, mudslides, and landslides. This paper reviews the main progress in short-duration heavy precipitation in China in recent years, and compared the relevant research findings of the United States and Europe briefly, covering the spatiotemporal distribution characteristics and diurnal variation characteristics of short-duration heavy precipitation; the atmospheric circulation situation and environmental conditions for the occurrence and development of short-duration heavy precipitation in major regions of China; the radar echo characteristics and raindrop characteristics; the impact of topography and urbanization on short-duration heavy precipitation and its mechanism; and then the application of artificial intelligence in the potential forecasting, short-term forecasting, and nowcasting of short-duration heavy precipitation in China. With global warming, the frequency and intensity of short-duration heavy precipitation are increasing. In the future, it is necessary to further study its formation mechanism and environmental conditions, improve the spatiotemporal resolution of observations, strengthen the application of new observation data, enhance the forecasting capability of highresolution rapid update cycle assimilation numerical weather prediction models through the fusion analysis of multi-source and dense observation data, optimize the deep learning model and algorithm, especially in the development of large deep learning models to enhance the forecasting and early warning capabilities for shortduration heavy precipitation.
  • WANG Wenyu, XU Jian, WANG Zhenzhan, LU Hao, LIU Jingyi, ZHANG Dehai
    Online available: 2024-12-12
    Abstract: Long-term observations and data analysis of the Earth’s middle and upper atmosphere, an important region for the study of atmospheric processes and even climate change for the study of human activities and climate change, are still sorely lacking. Terahertz limb-sounding technology can obtain atmospheric profiles all day and near all-weather with high vertical resolution (about 1~5 km), and is particularly sensitive to some of the halogen gases associated with ozone depletion which is an important method to measure the Earth's middle and upper atmosphere parameters. The Earth’s middle and upper atmosphere constitutes a crucial region for studying atmospheric processes and even climate change. However, there remains a significant lack of long-term observational data and comprehensive analysis for this atmospheric layer. Terahertz limb sounding technology has emerged as a vital tool for measuring atmospheric parameters in these regions, capable of obtaining atmospheric profiles with relatively high vertical resolution (1~5 km) under near-all-weather conditions with diurnal availability. Particularly sensitive to halogen gases associated with ozone depletion, this technology offers unique advantages. Focusing on terahertz limb sounding technology, this study systematically reviews the technological evolution and current status of terahertz payloads: While existing systems have successfully achieved high vertical resolution measurements of multiple trace gases in the middle and upper atmosphere, current payloads still face challenges such as bulky system configurations and inadequate noise suppression capabilities. Based on newly developed prototype payloads, next-generation terahertz detection systems primarily emphasize advancements in low-noise and miniaturization technologies. Regarding data processing, conventional physical retrieval algorithms suffer from low computational efficiency. The introduction of artificial intelligence technology demonstrates potential to significantly enhance retrieval efficiency while maintaining accuracy. Future development urgently requires breakthroughs in core technologies including terahertz low-noise receivers and high-resolution digital spectrometers, which will further propel the advancement of terahertz limb sounding technology in China.
  • NI Jie, WU Tonghua, ZHANG Xue, ZHU Xiaofan, CHEN Jie, DU Yizhen
    Online available: 2024-11-19
    The Three Rivers Source Region (TRSR) is an important water source and ecological reserve in China, and revealing the changes in the characteristics of its freeze-thaw index can provide a scientific basis for the assessment of the local permafrost environment as well as the response to climate change. In this study, the temporal and spatial characteristics of the Air Freezing and Thawing Indices (AFTI) in the TRSR for the period 1979-2022 were analyzed using the day-by-day air temperature data from a high-resolution near-surface meteorological forcing dataset for the Third Pole region (TPMFD) by means of air freezing and thawing index and other methods. The results show that the mean value of the freezing index in the TRSR over the past 44 years is 1 930.23 °C·d, exhibiting a spatial pattern of gradually decreasing from west to east. In contrast, the thawing index displays an opposite spatial pattern with an average value of 879.25 °C·d. Overall, the freezing index in the TRSR has shown a fluctuating decreasing trend at a rate of -10.01 °C·d/a for the last 44 years with an abrupt change in 2001, while the thawing index has shown a fluctuating increasing trend at a rate of 6.29 °C·d/a with no significant abrupt change. Altitude, as a key factor of freezing and thawing indices in the TRSR, showed a significant correlation, and for every 100 m increase in altitude, the thawing index in the TRSR decreased by about 87 °C·d, and the freezing index increased by about 107 °C·d.
  • SONG Wanjuan, WANG Li, XU Shiguang, HUANG Ni, NIU Zheng
    Online available: 2024-11-08
    Deep space exploration, serving as a pivotal avenue for uncovering the universe's mysteries and fostering sustainable development, has emerged as the foremost strategic frontier in space technology. After decades of development, this technology has been widely used in the exploration of various celestial bodies in the solar system. In February 2015, the first deep space exploration satellite targeting the Earth, the Deep Space Observatory (DSCOVR), was successfully deployed at the Sun-Earth Lagrange Point 1 (L1), providing new perspectives and data for the study of Earth system science, while also posing new challenges to traditional satellite data research. This paper comprehensively analyzes more than 100 related papers and conference summaries published on the official website of the National Aeronautics and Space Administration (NASA) since the launch of DSCOVR. From the three levels of basic research, applied research and special research, this paper comprehensively reviews the development status, advantages and future development direction of deep space earth observation. This study reveals that deep space Earth observation can integrate existing satellite-aircraftground systems, establishing a benchmark for multi-source data fusion to create globally comprehensive, highfrequency temporal, and multi-spectral datasets for an integrated Earth observation system. It provides temporally consistent, spatially continuous, and spectrally stable global observation data, showing significant potential in the study of large-scale geophysical phenomena across the atmosphere, biosphere, hydrosphere, and lithosphere. Future advancements in sensor innovation, optimized detection technologies, and diversified observation points are expected to enable all-temporal, all-directional, and all-dimensional Earth observation. This will enhance our understanding of physical, chemical, and biological systems on Earth.
  • YU Wenzheng, WANG Minyan, WEI Zhudeng, YU Longhui
    Online available: 2024-11-08
    To investigate the evolution of extreme runoff at the regional scale and its climatic driving mechanisms, the Huangshui River Basin, sensitive to climate change, was selected as a case study. Daily average flow data were collected from seven stations within the basin. Mann-Kendall (M-K) trend analysis and mutation tests were used to assess the interannual variation of extreme runoff and its associations with extreme precipitation and extreme high temperatures.The results show that over the past 60 years, the extreme high flow index in the basin has decreased significantly, while the extreme low flow index has increased notably. The frequency index did not show any significant trend, but all indices demonstrated persistence. A mutation in the high flow index occurred around 2000, while mutations in the low flow and frequency indices were noted in 2010. In terms of cycles, a short cycle of approximately three years was observed for all indices. Additionally, the frequency index exhibited a long cycle of 32.5 years. The variations in runoff were significantly related to an overall increase in extreme precipitation intensity, a decrease in precipitation duration, and the intensification of extreme high temperatures in the basin. Extreme high flow was positively correlated with extreme precipitation and negatively correlated with extreme high temperatures. In contrast, extreme low flow showed a primary positive correlation with extreme high temperatures, with a less significant correlation to extreme precipitation. These findings provide important insights for the utilization of water resources and flood disaster reduction in the Huangshui River Basin.
  • DU Jingwen, TONG Chenchen, HUANG Ching-Sheng
    Online available: 2024-11-08
    Deriving shape factor in analytical models for flow in double-porosity media is partially empirical. This study proposes a new flow equation and new shape factor for matrixes without empirical derivations in considering the problem of the standard pumping test in double-porosity confined aquifers. For a single fracture-strip matrix medium, a new analytical model incorporating the new flow equation and new shape factor is developed; the analytical solution is derived. For a fracture network-matrix medium, a finite element solution depending on the new flow equation and new shape factor is built without discretizing the space in each matrix. Results show the shape factor for the strip matrix is the reciprocal of the square of the matrix width, for the circular matrix is the reciprocal of the square of the radius, but for other shapes of matrix is an empirical parameter. The relative error of the fracture drawdown predicted by the analytical solution with the new shape factor is less than 5%. The relative error considering existing shape factors is, however, about 99%. When the ratio of the fracture area to the total medium area (defined as fracture density) exceeds 62%, the fracture networkmatrix medium can be regarded as a double-porosity continuous medium. The finite element solution has applied to a field standard pumping test.
  • WANG Shuting, CAO Shuyun, ZHAN Lefan, LIU Jianhua, CHENG Xuemei
    Online available: 2024-11-08
    It is of great significance to clearly define the mineral deformation and slip system for in-depth analysis of the intrinsic mechanism of mineral response to external stress and temperature, as well as its rheological weakening process. The rapid development of science and technology and its deep integration in the geological field provide an opportunity for detailed analysis of structural deformed behavior and mechanism. This study takes quartz and amphibole in typical naturally deformed rocks as examples. Based on microstructure analysis, the comprehensive analysis was conducted on the massive mineral lattice preferred orientation data accumulated using the Electron Backscatter Diffraction (EBSD) probe mounted on the Field Emission Scanning Electron Microscope (FESEM). Based on microstructural features, EBSD mapping data, dislocation geometry types, and properties, a detailed analysis method for grain boundary trace and misorientation (axes) is elaborated. It is revealed that strain adjustment and grain refinement process of the quartz are mainly through the {m} slip system dominated by subgrain rotational recrystallization mechanism in quartz veins. It is also found that in mylonitic amphibolites, the amphibole porphyroclasts exhibit strong deformation behavior of fine-grained under the dominance of subgrain rotational recrystallization. The amphibole exhibits the interaction of multi-slip systems dominated by the [001] direction through dislocation creep in the banded amphibolites. Therefore, combining the EBSD grain boundary trace with the misorientation axis analysis method and microstructure features can completely count the micro-geological information (composition, shape, grain size, orientation, boundary, strain, etc.) of deformed minerals, and well reveal the orientation evolution law from the grain interior to between grains (or matrix). Moreover, the dominant slip system in the mineral deformation process can be effectively defined and related to the deformation environment, which has important geological significance.
  • LI Jun, ZHAO Yang, CHEN Zhaozhou, ZHANG Lele, CAO Huan, LI Shichang
    Online available: 2024-10-18
    Abstract: The prediction of borehole collapse pressure plays a key role in drilling safety, reducing construction cost and realizing efficient drilling. The fracture development in complex ultra-deep geological conditions has a great influence on the prediction of borehole collapse pressure. The conventional methods are mostly based on finite element simulation for 3D geomechanical modeling and 3D collapse stress prediction. Although the method is highly accurate, it requires huge computing power resources. In order to solve this problem, an efficient and fast in-situ stress modeling method flow driven by seismic data is proposed in this paper, which is then used for 3D collapse pressure prediction. Firstly, combined with multi-scale data of pre-stack seismic and rock mechanics logging, a combined spring model with curvature properties is established to complete the efficient and rapid modeling of three-dimensional in-situ stress field, and is used to calculate threedimensional borehole stress. Secondly, based on the maximum likelihood attribute, the fracture development is obtained from 3D seismic data to provide 3D weak surface attribute parameters for the study area. Finally, the collapse model of sliding along fracture plane is calculated by using Mohr-Coulomb criterion, and the collapse pressure prediction of fractured formation is realized from one-dimensional logging data to three-dimensional working area. The method is applied in the woodworking area of Tari, and the results show that the prediction results of the model are in good agreement with the measured data, reaching 93.79%. The prediction results of collapse pressure are in good agreement with the interpretation results of formation microresistivity scanning imaging, which verifies the feasibility of this method in predicting borehole wall collapse events. This study can realize the rapid modeling of collapse pressure with high precision, and effectively provide an integrated solution of geological engineering for drilling construction in ultra-deep and complex areas.
  • LEI Wenjie, LUO Dongliang, CHEN Fangfang, LIU Jia, PENG Yifei, LI Shizhen, SHEN Qi
    Online available: 2024-10-18
    Abstract:The thermal regime of soil is vital for indicating the presence and thermal stability of permafrost. To investigate the long-term changes in the thermal regime of permafrost in the Headwater Area of the Yellow River (HAYR), we first constructed a mathematical model for soil heat transfer to simulate the dynamics of ground temperatures at six boreholes using the HYDRUS-1D model. The reliability and applicability of the model were confirmed through parameter calibration procedures. Subsequently, the changes in permafrost thermal regime from 1979 to 2018 in the HAYR were simulated using monthly air temperature data extracted from the China Meteorological Forcing Dataset (CMFD). The model simulations revealed an abrupt change in mean annual ground temperature in the HAYR after 1999. Prior to 1999, the changing rates were from ?0.037 to 0.026 °C/a, whereas after 1999, they ranged from 0.006 to 0.120 °C/a. The abrupt increase in mean annual air temperature in 1998 and the occurrence of extreme climate disasters in 1999 were identified as the primary reasons for the sudden changes in permafrost thermal regime in 1999. The rise in permafrost temperature and the decrease in its thermal stability are expected to have various impacts on the water resources conservation function and biogeochemical cycle. This study can provide scientific and technological support for clarifying the response patterns of plateau permafrost to climate change and for strengthening zoning and control of the ecological environment in the HAYR.
  • SUN Jianhua, TIAN Fuyou, XIA Rudi, ZHENG Linlin, HUANG Yue
    Online available: 2024-10-18
    Abstract:To improve the understanding of the formation mechanism and forecast accuracy of severe convective winds(SCWs), the important achievements of the formation mechanism and forecasting methods of severe convective winds and related convective systems were reviewed. Firstly, the spatial and temporal distribution characteristics of severe convective wind in the world are briefly introduced. SCWs in China mainly occur in the eastern region, with high-frequency areas in northern North China, central and southern Northeast China, and Guangdong Province. Then, the relationship between the organizational modes and structural features of the parent convective systems that generates SCWs, the influence of atmospheric environmental conditions, forecasting methods are summarized. Squall lines and bow echoes are important convective systems that generate SCWs, especially strong SCWs. The rear inflow jet and meso-γ-scale vortices in squall lines or bow echoes are important structural features that generate SCWs. The environmental conditions and forecasting methods for SCWs are summarized. The environmental thermal and dynamic factors can affect the generation and intensity of SCWs, but the intensity of convective activity mainly depends on the covariant relationship between convective effective potential energy and vertical wind shear. Numerical model forecasting, physics-based methods (ingredients-based method), and deep learning/machine learning methods are currently the main methods used in short-term forecasting operations for SCWs. Finally, it is indicated that the following issues associated with SCWs in China should be studied, including detailed spatiotemporal distribution characteristics, formation mechanisms of SCWs under different environmental conditions, and forecasting methods.
  • HE Jinqiu, LI Haipeng, HOU Mingcai
    Online available: 2024-10-18
    Abstract:The study of source-to-sink systems is an important field of research focused on understanding the entire process of material transport from source areas, such as mountain ranges or other landforms, to sink areas like river basins, lakes, or the ocean. This process involves the weathering of parent rock, the erosion of materials, their transport via various agents (such as wind, water, or ice), and their eventual deposition at sink locations. Analyzing this system helps reveal dynamic surface changes, material cycling mechanisms, and how these processes respond to environmental shifts over time. Understanding these complex processes is crucial for a variety of scientific fields, including geomorphology, environmental science, and natural resource management. Traditional methods used to study these systems, such as field observations and laboratory analyses, often face several limitations. Data availability, low spatial-temporal resolution, and ambiguity in interpretation make it difficult to capture the rapid and dynamic changes occurring in natural systems. Furthermore, these methods are not well-suited for analyzing long-term evolutionary processes or large-scale systems. As a result, numerical modeling has become a critical tool in the study of source-to-sink systems, addressing these traditional limitations by simulating complex processes over varying spatial and temporal scales. These models provide more quantitative insights into the dynamics of erosion, transport, and deposition under different environmental conditions.This paper highlights five key numerical tools commonly used in source-to-sink research: Dionisos, SEDSIM, Landlab, goSPL, and Delft3D. Each tool has specific advantages that make them suitable for different research needs. Dionisos, for instance, is particularly effective for modeling large-scale, long-term basin filling processes, but it may not be as effective for simulating small-scale, dynamic changes. SEDSIM, which is based on hydrodynamic equations, offers highly accurate results, especially in clastic sedimentary processes, though it tends to be slower and more focused on specific types of sediments. Landlab is highly customizable and capable of multi-process simulations, but it requires advanced programming skills for its effective use. goSPL excels at handling global-scale, high-resolution simulations, though it struggles with localized phenomena and demands significant computational resources. Delft3D, meanwhile, is ideal for small-scale, fine-detail simulations, particularly in coastal, riverine, and lacustrine environments, although it faces challenges in large-scale applications.As computational power continues to grow and algorithms improve, future advancements in sourceto- sink modeling are expected. The integration of big data and AI will likely play a key role in driving further developments, enabling more accurate predictions, facilitating multidisciplinary integration, and fostering the intelligent evolution of the field.
  • HUANG Baorong, ZHOU Zhe, CHU Huaqiang, DAI Chaomeng, YANG Shouye, ZHANG Yalei
    Online available: 2024-10-18
    Abstract:Carbon neutrality is a crucial strategy for combating global warming, and Negative Emissions Technologies (NETs) are key to achieving this goal. The ocean, as the largest carbon reservoir on Earth, plays an irreplaceable role in regulating the global carbon cycling and holds significant potential for negative emissions. Ocean alkalinity enhancement is regarded as a highly efficient and ecologically beneficial negative emissions technology. This technology not only increases ocean alkalinity by adding alkaline minerals to seawater, thereby enhancing the absorption of atmospheric CO2, but also improves the buffer capacity to resist the ocean acidification. This study introduces the mechanisms and advancements in ocean alkalinity enhancement research at multiple scales, based on the dissolution theory of carbonates in the ocean. Assessing the potential for negative emissions and associated costs reveals several challenges regarding implementation pathways, environmental impacts and public acceptance. Considering the specific conditions of China's coastal regions and the characteristics of ocean alkalinity enhancement technology, the study proposes the pathway integrated with wastewater treatment plant and coastal engineering. Furthermore, it presents an innovative concept on the application of ocean alkalinity enhancement and enriches the scientific understanding of blue carbon sinks.
  • LI Yue, WANG Ying, LI Yuecong, ZHANG Ruchun, MA Linyuan, YOU Hanfei, WANG Rongrong, CAO Yihang, XU Qinghai
    Online available: 2024-10-17
    阿里地区作为高寒荒漠草原的代表区域,是青藏高原独有的荒漠草原类型。其相对花粉 产量和相关花粉源范围,是基于花粉进行植被和气候定量研究的重要参数之一。基于阿里地区37 个样点的现代表土花粉和植被数据,利用ERV模型的不同子模型,以藜科花粉为参考种,估算了禾 本科、藜科、蒿属、菊科、十字花科和委陵菜属6 种主要花粉类型的相对花粉产量及相关花粉源范围。 结果显示,子模型2 估算结果最为理想,计算得到的研究区相关花粉源范围为1 550 m。主要花粉类 型的相对花粉产量如下:藜科(1.000),蒿属(1.286±0.058),菊科(0.689±0.043),委陵菜属(0.139± 0.008),十字花科(0.763±0.063)和禾本科(0.003±0.006)。留一法和REVEALS 模型检验表明,上述 相对花粉产量和相关花粉源范围结果均较为可信,可应用于区域植被重建。
  • LIU Yu, WU Zhijun, PU Xiao, MIN Xiangyu, SHENG Anxu, LI Ziyan, CAI Yanjiang, YU Zhen, ZHANG Jianjun
    Online available: 2024-09-27
    Abstract: Statistical analysis was conducted on submission, acceptance, review and grant funding of various projects managed by the discipline of Environmental Geosciences, Department of Earth Sciences, National Natural Science Foundation of China in 2024. Academic achievements of the completed projects in 2023 were partly summarized according to research subjects. This might provide enlightenment for potential project applicants.
  • ZHANG Liang, WANG Dong, ZHANG Xiaowen, ZHANG Jianheng, LU Shasha, LENG Shuying
    Online available: 2024-09-27
    Abstract:The application, peer-reviewing and funding statistic data of different types of projects in the Marine and Polar Sciences Division (Code: D06) in the Department of Earth Science at National Natural Science Foundation of China (NSFC) in the year of 2024 are analyzed in this article. Issues found in the management of NSFC funds are summarized as well. The information could help researchers to improve the quality of their proposals for NSFC funds and final reports of completed projects. In summary, D06 received proposals in General Program, Youth Science Fund, and Less Developed Regions Fund from 409 institutions in 2024, 46 more than last year. The number of proposals received in D06 raises to a new record of 3 191, 702 more than last year. In terms of final reports of completed projects, more projects added NSFC project number into the acknowledgement of their publications. However, the quality of some final reports could still be improved according to the rules.
  • LI Wei, GE Fei, YANG Yali, HE Jianjun, SHANG Huazhe, LIU Zhijuan
    Online available: 2024-09-27
    Abstract:The DivisionⅤ(Atmospheric Sciences Discipline) of the Department of Earth Sciences, National Natural Science Foundation of China (NSFC), has successfully completed the application, mail review, panel review, and funding results summaryof 2023 as scheduled. In terms of project applications, the Atmospheric Sciences Discipline received 2 312 applications for General Program, Young Scientists Fund, and Fund for Less Developed Regions in 2024, with an increase of 19.9% compared to 2023. From the perspective of review results, the comprehensive scores of the mail reviews for these three types of projects in 2024 were slightly lower than those in 2023.When determining the priorityprojects for panel review, the discipline layout wasconsidered.Two sections (i. e., the second-level application codes D0509 to D0515) were appropriately tilted toward the Supporting Technology and Development Fields. Under the equal conditions, preference was given to female applicants. After the panel review, the Atmospheric Science Discipline funded a total of 423 projects in the above three types, and successfully completed the funding plan determined by the Earth Science Department.With the aspect of concluding achievements, a total of 337 projects were completed in 2023, with the indicators such asthenumberof publications slightly increased compared to 2022.
  • GAO Yang, XIONG Juhua, ZHANG Zhonghao, LIU Jian, GENG Jing, ZHANG Da, GAO Linlin, WANG Fenglong, XIE Haichao, LI Wende
    Online available: 2024-09-25
    Abstract: National Natural Science Foundation of China (NSFC) is the main funding institution of fundamental research in China. Geography (or geographical science), as an important component of Earth sciences, is a fundamental discipline that studies the patterns of spatial differentiation, temporal evolution processes, and interaction mechanisms of natural factors, human elements, geographic information, and geographic complexes. It mainly includes three sub-disciplines: human geography, physical geography, and information geography. The acceptance of grant project application, the review of proposals, and the evaluation of project reports for the geography discipline are centrally managed by the Division of Geography in the Department of Earth Sciences of NSFC. This paper introduces the application and acceptance, review process, deliberation, and funding status of the NSFC projects for the three major sub-disciplines of geography during the 2024 annual centralized acceptance period. A statistical analysis was conducted on the research outcomes of projects completed at the end of 2023, highlighting the main research advancements achieved by some selected projects.
  • ZHENG Yuanming, XIAO Jun, LÜ Zeng, LI Wenbiao
    Online available: 2024-09-19
    Abstract: This paper systematically analyzes the application, acceptance, evaluation, and funding of the projects managed by the Geochemistry Discipline (Application Code: D03) of the Earth Sciences Department of National Natural Science Foundation of China in 2024, and analyzes the project completion and precautions in 2023. In 2024, the total number of applications for geochemical projects increased by 21% compared to 2023, among which the number of general projects increased by 45.5%. In the past four years, the total number of supporting units applying for projects has kept increasing continuously, and Earth’s surface geochemistry (D0310) has become a new growth point of the discipline. The general projects and youth projects are mainly based on “free-exploration basic research”, while the key projects in the field of “resource and energy formation theory and supply potential” are mainly based on “goal-oriented basic research”. In recent years, geochemistry discipline has remained characterized by a relatively small number of applications and slow growth. In the future, in-depth research and discussions should be conducted on how to maintain the inherent strengths in isotopic theories and technologies within the geochemistry discipline, guide the deep integration of basic research with target orientation and national needs, and promote the deep intersection and integration of geochemistry discipline with other disciplines. While expanding the direction of the field, efforts should be made to create highquality and advantageous disciplinary directions in geochemistry.
  • ZHENG Yuanming, HUANG Yuangeng, WANG Yang, ZENG Gang, LANG Xianguo, LIANG Changyu, SONG Zezhang, REN Jianguo
    Online available: 2024-09-19
    Abstract:To better understand the application status of geological science funding projects, improve the quality of proposals and final reports, and identify the current research hotspots in this discipline, this article analyzes the application, review, and funding situation of geological science projects (Code D02) in 2024. It examines issues in the acceptance and review process, and summarizes the completion of the 2023 annual closing projects along with the main research progress across various disciplines. Additionally, using the proposals for the general and young scientists funds related to Earth’s ecosystem evolution and energy fields in 2024 as samples, the word cloud analysis method is employed to statistically analyze the keywords in these proposals. This analysis reveals the research hotspots in this field and each sub-discipline, providing a valuable reference for scientific researchers applying for projects.
  • ZHAO Zheng, LIU Cheng, FENG Xiao, CHEN Shuotong, GONG Jingwen, LIU Zhiwei, WANG Yan, XIA Shaopan, LIU Xiaoyu, BIAN Rongjun, ZHANG Xuhui, CHENG Kun, ZHENG Jufeng, LI Lianqing, PAN Genxing
    Online available: 2024-09-13
    Abstract:Ecosystem functions and services provided by soil in earth surface has been considered as the key foundation supporting global society and environment sustainability. All of these functions and services are closely linked to aggregate hierarchy system of the soil cover. In this review, key ecosystem functions and services provided by soil including accumulation and stabilization of organic carbon, biodiversity conservation, Extracellular Enzyme Activities (EEAs) mediating biogeochemical cycling are overviewed linking to development of aggregate hierarchy system. In particular, understanding these functions and services by aggregate system in line with methodology updating of aggregate separation, characterization and data analysis/ synthesis are discussed in depth. The discussions are focused on potential mechanistic linkage of multi-functions of these soil carbon sequestration, microbial diversity protection and EEAs modulation to the diverse micro-scale spatial pattern of the different hierarchies of aggregate size fractions. Following, the dual structure of soil aggregates and the associated pore system is highlighted in the diverse provisioning of the above mentioned functions and services. In the way, we point to the diversity of the aggregate-pore structure of the hierarchy aggregate systems of or within a soil as the key to understand the formation and development of the above mentioned functions and services for a give soil system. Meanwhile, through re-visiting and exploring the original data in some cases of soil aggregate studies published, we propose some novel methods for better characterizing the key roles of soil aggregate system in provisioning the ecosystem services and the improvement with rational practices or reasonable interference so as to guide sustainable soil management. Finally, comments on the importance of soil aggregate study in the research of Earth system sustainability. We urge a holistic understanding of soil aggregates as fundamental soil functioning units, instead of a direct agent in field process. Considering a key player in biogeochemical cycling and soil health, we call for a well-designed but long pursuing study of soil hierarchy aggregate systems and a global unification of soil aggregate characterizing and parameterization. This should be considered as a core foundation of soil system science in the late 21th century.
  • ZHAO Zheng, FENG Xiao, LIU Cheng, CHEN Shuotong, LIU Zhiwei, WANG Yan, XIA Shaopan, LIU Xiaoyu, BIAN Rongjun, ZHANG Xuhui, CHENG Kun, ZHENG Jufeng, LI Lianqing, PAN Genxing
    Online available: 2024-08-04
    Abstract:With the increasing concerns for ecosystem functioning and services provided by soil, the study on soil aggregates has been increasingly a streamline discipline of modern soil science with the continuing updating of consensus and the methodology. In this review, we provide a holistic overview of understanding and characterizing soil aggregate system emerged for over last two decades. Evolution of concepts of soil aggregation, size fractionation and structural characterization is displayed, and separation and examination of the biophysical structure are discussed, as well as the final core scientific consensus of soil hierarchy system is synthesized. The main point of view of understanding soil aggregates include the followings. ① Soil aggregates are considered as the minimum micro-architecture and functional units, comprised of mineral particles, organic matter and (micro-) biome via their interaction and co-occurrence, thus noting their basic functional particles of soil in nature; ② The micro-spatial distribution of soil aggregates at different hierarchy levels results in the heterogeneity but functional diversity of a soil; ③ The final nature of soil aggregates could be envisaged of the embedded bio-pore system, created via the dual structure of aggregate and the associated pore system governed by the hierarchy aggregate system; ④ A soil aggregate system is generally represented by the three major hierarchies of aggregate size fractions including macroaggregates, microaggregates and silt/clay fraction, with the macroaggregates formed via binding microaggregates and/or silt-clay particles with coarse organic matter in a mode of pomegranate; ⑤ Wet sieving of field moist samples are recommended for preparation of soil aggregate separates despite of dry or moist sieving often used for samples from dry lands; ⑥ The μCT tomography technology is a powerful tool to quantify and visualize the pore system of soil aggregates, potentially linking to soil life processes and ecosystem services. Global cooperation is urged to develop unified protocol for fractioning, quantifying and visualizing the soil hierarchy system of aggregates of world soils. With the developments, the complexed soil system, particularly of the biodiversity of soil, can be explored at aggregate scale. Based on the updated understanding and characterization of soil aggregate system, nature-based solutions for global soil management policy and technical options will be provided for developing Earth sustainability.
  • Zhou Guangsheng, Zhou Mengzi, Zhou Li, Ji Yuhe
    Online available: 2024-06-21
    The paper summarizes recent progress in the observation, mechanism and model of landatmosphere interaction, and pointed out that the existing observational studies have not taken into account the effects of both the changes of terrestrial ecophysiology and atmospheric boundary layer on land-atmosphere fluxes. As a result, they restrict the parameterization of land surface process, parameter inversion from satellite remote sensing, and the operational application of land surface process model. In order to realize comprehensive understanding of land-atmosphere interaction and the development of land surface process models, it is pointed out that the studies on the effects of changes in terrestrial ecophysiology and atmospheric boundary layer on landatmosphere interactions and the operational application of land-surface process models are needed to be emphasized in the future, the main tasks to be concerned include: (1) three-dimensional observation of the landatmosphere interaction across the boundary layer, (2) application of multi-source data in the land-atmosphere interaction across the boundary layer, (3) development and operational application of land surface process model.
  • Li Zhenghong, Zhou Liang, Gao Hong, Wang Wenda, Wei Wei
    Online available: 2024-06-16
    The development of mountainous towns is limited by terrain and landforms, resulting in an urban expansion model dominated by new city construction. The geographical spatial manifestation of this model is that the construction of new cities is far from the main urban area, and the urban construction land gradually expands towards higher slopes (i.e., the gradient expansion of construction land). Although gradient expansion solves the problem of land resource scarcity in mountainous towns, it also increases the risk of geological disasters such as land subsidence. Exploring the law of gradient expansion and identifying disaster risks are paramount. The study selected three new cities with severe gradient expansion as typical case areas and used DEM to obtain the gradient expansion areas of the new areas from 2017 to 2022. Based on Sentinel-1A SAR data from 2016 to 2020, SBAS InSAR technology was used to obtain surface deformation information, revealing the spatial correlation between gradient expansion and land subsidence in the new areas. ① The results show that from 2017 to 2022, the gradient expansion phenomenon in Yan’an New Area, Liangjiang New Area, and Lanzhou New Area was significant, with gradient expansion areas accounting for 53.5%, 51.0%, and 45.2%, respectively. Yan'an New Area, which is most severely affected by terrain, has the highest proportion of gradient expansion areas, and the gradient expansion speed is consistent with the urban expansion speed trend. ② The maximum settlement velocities in Yan’an New Area, Liangjiang New Area, and Lanzhou New Area are 28mm/a, 30mm/a, and 29 mm/a, respectively. Settlement mostly occurs at the front of the expansion of the new area, and there are different scale gradient expansion areas around the settlement area. ③ The intensity of gradient expansion is positively correlated with the rate of land subsidence, and the clustering distribution of areas with high gradient expansion intensity and high ground subsidence rate indicates that urban gradient expansion accelerates the occurrence of land subsidence in the expansion area. The study has positive significance in exploring the correlation between urban gradient expansion and land subsidence and promoting sustainable development of mountainous cities.
  • GE Jiawang, TANG Xiaolong, ZHAO Xiaoming, ZHU XiaoMin, QI Kun
    Online available: 2024-06-16
    Previous sequence stratigraphy research mainly focuses on the two-dimensional seismic interpretation in its dipping direction, while the variations of sequence architectures in vertical provenance direction is the focus and difficulty of current research. This study takes the Late Pleistocene (0.125 Ma to today) shelf margin stratigraphic successions of the Qiongdongdong Basin as an typical example. The internal structure and combination characteristics of the systems tract units are established and identified, according the methods of typical stratal terminations, stratal stacking patterns, and shelf-edge migration trajectory. The systems tract in the studied sequence are classified from bottom to top, including the lowstand systems tract (LST), the transgressive systems tract (TST), the highstand systems tract (HST), and the falling stage systems tract (FSST). Among them, the part of the interface within the falling stage systems tract (WSTS) divides the FSST into early and late phases. The WSTS interface is the transitional surface for the positive to negative angle of the migration trajectory of the shelf-edge and for the stratal stacking transition from progradation to degradation. The stabilized and collapsed types of shelf-edge sequence architectures have developed in the Upper Pleistocene of the western part of the eastern Qiongdongnan Basin. With the change of relative sea-level, the stabilized shelf-edge mainly develops multi-phase shelf margin deltaic and deep-water fan deposits, while the collapsed shelf-edge mainly develops large-scale canyons and mass transport deposits. In response to the a short sea-level rising but a prominent falling cycle, the late Pleistocene shelf-edge sequences are composed of thin or undeveloped LST and TST units, and a thick FSST unit, whereas the active faults in the outer shelf locations increase the proportion of the HST unit in sequences. The pre-existing slope break geomorphology, fault activities and asymmetric sea-level fluctuation coevally lead to a diverse of the sequence architectures in the study area. The quantitative exploration of highfrequency sequence stratigraphic driving mechanisms is the future development trend of the Pleistocene stratigraphy, and this study provides a potential reference significance for the standardization of 3D sequence stratigraphic investigations.
  • YAN Shishuai, YAN Quanshu, SHI Xuefa, YUAN Long
    Online available: 2024-06-16
    In the global subduction systems, the subduction input includes normal oceanic slabs and some buoyant oceanic plateaus. Both of them will exert different geological effects on the subduction zone. Thus, performing the study on the interaction of oceanic plateau and subduction zone will be significant for understand the subduction zone geodynamics and the lateral accretion processes of continental crust. This study summarized the geological and geophysical characteristics of some typical oceanic plateaus that are currently closing to a subduction zone. These, combined with geological and geophysical features of adjacent subduction zones and some recent numerical simulation data, have been used to discuss the geological effects of the interaction between oceanic plateau and subduction zone. In the aspects of kinematics and geometry, buoyant oceanic plateaus can generally resist subduction, lead to subduction retreatment and reversal of subduction polarity, and thereby form a new subduction zone. The subduction process in some subduction zones will be terminated due to the arrival of oceanic plateaus, and the plateaus finally accrete to the mature arc/crustal margins and become part of continental crust. However, recent studies have shown that part of oceanic plateaus does not lead to the termination of the subduction process, but rather contribute to the occurrence of flat subduction, thereby result in tectonic shortening and thickening of the overlying plate in the subduction zone area, and the gradual migration of magmatic activity toward intraplate setting. Geochemically, these oceanic plateaus with enriched compositions will not only affect subduction zone lava geochemistry and the formation of hydrothermal deposits, but possibly contribute to the formation of mantle heterogeneity. Finally, this study put forward some key scientific issues on the interaction of oceanic plateaus with subduction zones, including the detailed crust/mantle structure of subduction zone, the geological and geochemical response of the island arc and backarc basin to the new subduction tectonic framework of “Oceanic plateau-Trench”, and quantitative correlations between the factors controlling whether plateaus are accreted or subducted remain unclear.
  • LIANG Pengbin, MU Jianxin, GAO Yongpeng, TIAN Lide, LI Lintao
    Online available: 2024-06-04
    Abstract:Ice thickness and storage are the prerequisites for glaciological studies such as predicting future glacier changes, estimating available freshwater resources, and assessing potential sea level rise. Based on ground-penetrating radar (GPR) thickness data from 31 glaciers in western China, parameters of the GlabTop 2 (Glacier Bed Topography) model was calibrated and optimized. The simulation of ice thickness on the Qiangtang Plateau and the assessment of the total amount of glacier water resources reveal the following results: ①The average ice thickness simulated by the GlabTop2 model closely matches the measured average thickness, with a correlation of 0.87 and an RMSE of 18.2 m. Overestimation and underestimation of ice thickness by the model are 9% and -17% respectively. The ice thickness distribution along flow is better captured than the distribution across flow; ②The GlabTop2 model estimates that the ice storage of glaciers on the Qinghai-Xizang Plateau in 2022 is (177.6±26.6) km3, with an average ice thickness of (88.2±12.3) m. The glacier volume is mainly distributed between 5 600 and 6 200 m, amounting to (148.28±22.24) km3, which accounts for 84.4% of the total glacier volume of the Qiangtang Plateau. The glacier volume in other elevation bands is relatively small.
  • ZHU Tangliu, LIU , Zhidan, ZOU Li, ZHONG Xihuang, XI Jiahong
    Online available: 2024-06-02
    Abstract: The high sequestration efficiency and strong sequestration potential of land-sea interaction regions are important nature-based, long-term solutions to climate change and the achievement of “carbon peaking” and “carbon neutrality”. In order to reveal the sources and forms of dissolved organic matter (DOM) in the land-sea interaction stratigraphy along the south coast of Laizhou Bay, and to enrich the understanding of carbon sources and sinks in the land-sea interaction region, the interstitial water from drill core was collected from November to December 2021 and analyzed for UV-visible absorption spectra and three-dimensional fluorescence spectral signatures of chromophoric dissolved organic matter (CDOM). The analyses showed that dissolved organic carbon and a(320) are both characterized by large and high concentrations after the second transgression. The difference in dissolved organic matter composition and properties of terrestrial-phase interstitial water is greater than that of marine-phase interstitial water. Of the five fluorescence components identified by parallel factor analysis and matched by OpenFlour, the humus-like components contributed 77% of the total fluorescence intensity, except for the bottom stratum. The fluorescence index and biogenic index show that the core interstitial water chromophoric dissolved organic matter is dominated by the contribution of microbial reproduction activities, and the longer the burial, the more significant the microbial contribution, and there is no significant difference between the terrestrial and marine phases. The results of principal component analysis show that the compositions have some differences in different sedimentary stages, but the composition and properties of the interstitial water dissolved organic matter gradually converge as the sedimentary process occurs. The humus is highly matured in long time scales.