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  • Weijing MA, Yaochen WANG, Jingwen KOU, Haijiang YANG, Bing XUE, Xiaohua GOU
    Online available: 2023-11-24

    The matching of water and land resources often directly affects the food production situation in various regions, and is the basis for high-quality economic and social development and agricultural production modernization. Taking nine provinces along the Yellow River as an example, based on the cross-coupling of four elements, namely natural background of water resources, water resources for total water consumption control, the study construct a ternary synergistic model of water-cultivated land-grain by cross-coupling. The matching coefficients of water and soil resources from 2010 to 2020 under each scenario were calculated, and the temporal and spatial evolution characteristics of water and soil resources matching along the “province-city” scale of nine provinces along the Yellow River and the contribution degree of each element were analyzed. The results show that: (1) The matching degree of binary water and soil resources based on the natural background of water resources in nine provinces along the Yellow River is improved as a whole, and the matching pattern of water and soil resources is relatively stable but the regional differences are obvious, which is manifested as “high in the west and low in the east”. (2) Along the three-way coordinated matching pattern of water-arable land and grain in nine provinces along the Yellow River, from the perspective of the total amount of cultivated land and the amount of irrigated arable land in the natural background of water resources, three distribution patterns are roughly presented: The western and northeastern regions are severely water shortage areas, the northern and north-central regions usually have different degrees of water shortage, and the central and central and eastern regions show a diversified distribution pattern; From the perspective of total water consumption control, there is a big difference between the total amount of cultivated land and the three-way cooperative matching pattern of irrigated cultivated ground. (3) Under the four scenarios, the average contribution rate of water resources exceeded 50%, and the sum of the effective utilization coefficient of irrigation water and the contribution rate of irrigation quota exceeded 30%, indicating that increasing the effective utilization coefficient and setting a reasonable irrigation quota had a decisive impact on the change of water and soil resources matching. The results are helpful to increase the understanding of the relationship between water resources and exploitation, cultivated land production capacity and reclamation, and the interdependence and constraint of grain planting structure.

  • Minglan XU, Lin DU, Maofa GE
    Online available: 2023-11-24

    Aerosols over the oceans are of interest because of their climatic and environmental effects. When bubbles in seawater rise to the surface and burst, they enrich surface-active substances present in the sea surface microlayer into marine aerosols, thus affecting their physical and chemical properties. The sources and quantitative characterization methods of marine surface-active substances were reviewed. The effects of surface-active substances on the number concentration and particle size distribution of marine aerosols were elaborated, and the influencing mechanisms on the hygroscopicity, cloud condensation nucleation activity and ice nucleation activity were summarized. Due to different sources, types and other environmental conditions, the effects of surface-active substances on marine aerosol generation and physicochemical properties vary significantly, which makes it difficult to study the environmental and climatic effects of marine aerosols. In the future, further observational and modeling research on surface-active substances will be required to provide scientific support for improved regional and global modeling of marine aerosols.

  • SONG Wenjie, LIANG Yuzheng, TAO Zhen, ZHONG Qingxiang, HE Yicong
    Online available: 2023-11-24
    Soil organic carbon (SOC) comprises a crucial component of terrestrial ecosystem carbon pool because of its larger storage and longer resident time. Smaller changes in the SOC pool will have a significant impact on terrestrial carbon flux and the global climate change. The mechanism of composition, transformation and stability of SOC are mainly controlled by soil microbial properties. Therefore, this paper reviews the research results on the formation, transformation and stabilization of SOC mediated by microorganisms, aiming to further understand the function of soil carbon sequestration. SOC consists of plant-driven carbon and microorganismsdriven carbon. Plant carbon is the main source of SOC. Soil microbial activity is the main driving force for SOC formation, transformation and stabilization. Soil microorganisms decompose plant carbon to form easy turnover soil particulate organic carbon through “ex vivo modification” pathway. Microbial residual carbon (MRC) produced by soil microorganisms through “in vivo turnover” pathway and mineral-associated organic carbon (MAOC) formed by the interaction with soil clay minerals contribute to the stable SOC components, of which, the contribution rate of MRC to stable SOC was 38.74%. The equilibrium between the “priming effect” and the “ongoing buried effect” regulates the storage and stability of SOC. At the global scale, microbial activity mediating SOC change is subject to annual precipitation and soil environmental factors (SOC, TN, pH). In response to global changes, the mechanism of SOC quantity and quality controlled by coupling plant litter, microbial activity and soil matrix should be pay more attention, and Environmental dependence of microbial carbon use efficiency for understanding the carbon sequestration effect from soil microorganisms in the future.
  • Jun SUN, Ting GU, Dai JIA, Yang FU
    Online available: 2023-11-20

    N2O is an important greenhouse gas that also has a damaging effect on the ozone layer. N2O emissions have been observed during microalgae cultivation and in microalgae-based ecosystems such as eutrophic lakes. However, little has been reported on the important role of N2O balance in algae and the potential algal N2O production pathways. Relevant studies on N2O synthesis and fixation by algae in recent years are reviewed, with the main contents including the development of studies on the relationship between algae and N2O emissions, several possible pathways of N2O production and consumption in algae, the influence of the algal microenvironment on the distribution pattern of N2O, and the potential impacts on global climate change. However, considering that the Intergovernmental Panel on Climate Change currently does not consider the possible N2O emissions during algal blooms or algal aquaculture, it is called upon to intensify experimental studies related to algal N2O production globally, in order to take an important step towards a comprehensive clarification of the important roles played by algae in the emission and fixation of N2O and towards the comprehensive assessment of greenhouse gas emissions from aquatic ecosystems.

  • Wenjie SONG, Yuzheng LIANG, Zhen TAO, Qingxiang ZHONG, Yicong HE
    Online available: 2023-11-20

    Soil Organic Carbon (SOC) comprises a crucial component of terrestrial ecosystem carbon pool because of its larger storage and longer resident time. Smaller changes in the SOC pool will have a significant impact on terrestrial carbon flux and the global climate change. The mechanism of composition, transformation and stability of SOC are mainly controlled by soil microbial properties. Therefore, this paper reviews the research results on the formation, transformation and stabilization of SOC mediated by microorganisms, aiming to further understand the function of soil carbon sequestration. SOC consists of plant-driven carbon and microorganisms-driven carbon. Plant carbon is the main source of SOC. Soil microbial activity is the main driving force for SOC formation, transformation and stabilization. Soil microorganisms decompose plant carbon to form easy turnover soil particulate organic carbon through “ex vivo modification”pathway. Microbial Residual Carbon (MRC) produced by soil microorganisms through “in vivo turnover” pathway and mineral-associated organic carbon (MAOC) formed by the interaction with soil clay minerals contribute to the stable SOC components, of which, the contribution rate of MRC to stable SOC was 38.74%. The equilibrium between the “priming effect” and the “ongoing buried effect” regulates the storage and stability of SOC. At the global scale, microbial activity mediating SOC change is subject to annual precipitation and soil environmental factors (SOC, TN, pH). In response to global changes, the mechanism of SOC quantity and quality controlled by coupling plant litter, microbial activity and soil matrix should be pay more attention, and Environmental dependence of microbial carbon use efficiency for understanding the carbon sequestration effect from soil microorganisms in the future.

  • Shuai YIN, Hanlin LIU, Jianhua HE, Rufei WANG, Xiangxue LI, Zheng HUANG, Yongqiang ZHOU, Zixiao HE
    Online available: 2023-11-20

    Geo-stress is an important geomechanical property of underground rock, and the accurate evaluation of its magnitude and direction is of great significance to the stimulation scheme design of tight oil reservoir. In this paper, taking the tight oil sandstone reservoir as an example, the comprehensive evaluation of the magnitude and direction of geo-stress under the constraint of rock mechanics, differential strain, hydraulic fracturing and microseismic monitoring is systematically carried out. The results show that the three principal stresses all are a function of the buried depth. Fracturing is a tensile fracture and is directly affected by the horizontal minimum principal stress, so there is a good positive correlation between the fracture pressure and the horizontal minimum principal stress. There is no direct relationship between the rupture pressure and the horizontal maximum principal stress, which is mainly affected by rock strength and can reflect the Poisson's ratio property. Therefore, the horizontal maximum principal stress of rocks with high rupture pressure may be relatively low. Based on well wall caving method, drilling induced fracture method, focal mechanism analysis and microseismic monitoring, the present crustal stress direction of the target layer is determined to be NE45°~NE60°. The existence of natural fractures will lead to the deflection of the expansion direction of local artificial fractures, and the expansion of pressure fractures is mainly affected by the distribution and opening of natural fractures. Furthermore, the hydraulic fracture height and half-fracture length show negative correlation, and the natural fracture opening has a certain influence on the control of hydraulic fracture height. This study can provide scientific guidance for the evaluation of fracturing effect in highly heterogeneous tight oil reservoirs.

  • LIU Shaojun, LIU Yong, ZHAO Shengxian, ZHANG Jian, DENG Naier, DENG Hucheng, HE Jianhua, XU Hao, CAO Lieyan, HE Yuanhan, YIN Meixuan
    Online available: 2023-11-08
    Abstract:Stress field characterization and evaluation is an important part of deep shale gas exploration and development, which is of great significance in guiding the prediction of fracture crack direction, well network deployment and horizontal well location deployment. Taking Longyi 1 sub-section in Luzhou North District, Sichuan Basin as an example, through indoor experiments, logging interpretation comparison and stress field simulation prediction, we established the conversion relation equation of rock mechanics dynamic and static parameters, clarified the single well geostress characteristics, and completed the stress field perturbation analysis, realizing the zoning portrayal of the stress field in the study area. The results of the study show that: ① the rock mechanical parameters show the characteristics of “high Young’s modulus and low Poisson’s ratio”, which indicates that the target layer has high brittleness. The three-directional stress increases with the increase of burial depth, and the relationship between the stresses is SH > Sv > Sh. ② Comparison and analysis of four stress direction discrimination methods show that the horizontal maximum principal stresses in the study area range from 105° to 115° . The Fuji oblique inclination is deflected counterclockwise with respect to the regional stress direction between 75° ~85° , and the Desheng oblique inclination often maintains the regional stress direction. ③ Comparing the regional stress state, the dorsal inclined area is affected by the tensile stress, with the stress value decreasing and the stress direction being deflected clockwise; and the oblique inclined area shows the opposite tendency by the influence of the extruding stress. The maximum range of stress perturbation by fractures can be up to 1.8 km, and the intensity of stress perturbation by fractures with different strikes is ranked as NEE, NE, and NNE. ④ Based on the characteristics of fractures and stress field perturbation, the study area is classified into three types, namely, adjusting, transforming, and stabilizing zones. The results of this study provide an effective support for the optimization of subsequent development units to achieve a steady increase in the average EUR of a single well.
  • REN Jianguo, WANG Yang, LÜ Dawei, CHAI Peng, LI Dan, LI Zhiqing, XIAO Di
    Online available: 2023-10-09
    In order to better understand the application process and outcome of projects in the field of Geological Sciences, improve the quality of project applications and final reports, and understand the current research hotspots of this discipline, we analyzed the application, review, and funding outcomes of 2023 geology projects (application code D02). Problems in the process of proposal review and acceptance were identified. This paper summarizes the completion of the final project in 2022 and the research progress in the major disciplines. In particular, project proposals from 2023 and youth fund applications in the relevant branches of the field of deep Earth processes and dynamics were examined. The keywords of the set of applications from 2023 were analyzed using the “word cloud” statistical analysis method. The research hotspots in this field and each branch discipline were determined to provide a guide for future project applicants.
  • LI Wei, XIAO Jun, KANG Jinting, FANG Chenchen
    Online available: 2023-10-08
    We analyzed the 2023 funding schemes managed by the Division of Geochemistry (application code: D03), Department of Earth Sciences, National Natural Science Foundation of China, with the goal of understanding the challenges faced by the foundation and finding solutions. Data from the past five years related to the number and type of applications, rate of acceptance, peer review process, and funding status were included in our analysis. The summarized results show that: ① the total number of applications received by the Division of Geochemistry has decreased by 5.1% compared with the number received in 2022; ② in terms of research field, the group of applications coded as “surface geochemistry” was the fastest growing group, entering the top three codes in the Division of Geochemistry; and ③ the applicants and principals of projects in the Division of Geochemistry are all more than one year younger than the average age of all applicants under the Department of Earth Sciences. Overall, the Division of Geochemistry faces the challenges of small quantity of projects and slow growth; however, it has the advantage of relatively young research teams. To strengthen future development in the field of applied geochemical research, continued support of basic research (including theoretical and methodological studies) is needed on theories and methods. The research advances presented in project reports completed in 2023 are also discussed.
  • CHENG Huihong, SUN Changqing, REN Jie, SONG Xiaogang, ZHOU Jun
    Online available: 2023-10-07
    We summarized and analyzed the project applications in the fields of geophysics and space physics under General Programs, Young Scientists Fund, Fund for Less Developed Regions, and other programs managed by the Department of Earth Sciences in 2023. In this analysis, we focused on the submission and acceptance statistics and process, review of proposals, and grant awards. Additionally, we summarized the important research progress made in the major branches of these disciplines in 2022.
  • LENG Shuying, ZHANG Liang, TAN Xiaoxiao, JU Peng, SONG Wei, MAO Wei
    Online available: 2023-09-27
    Abstract: To better understand the state of science research funding and improve the quality of both proposals and final reports, we analyzed the processes of application, review, and funding in the fourth division (i.e., Marine and Polar Sciences Division) of the Department of Earth Science. Problems that occurred during the peer review process in 2023 are identified and discussed, and the performance of completed and ongoing research projects in 2022 is assessed. Compared to 2022, in 2023, 36 more institutions submitted proposals to the General Program, Youth Science Fund, and Less Developed Regions Fund of the Marine and Polar Sciences Division. The total number of applications decreased by 6, with 56 in the general program, 33 in the Youth Science Fund, and 17 in the Less Developed Regions Fund. In addition, the final reports of the completed projects in 2022 had issues, such as a low ratio of first acknowledgement of funding and poor report writing.
  • JIANG Qiang, QIU Nansheng
    Online available: 2023-09-19
    The three Cretaceous oceanic large igneous provinces—the Kerguelen, Ontong Java, and Caribbean large igneous provinces—have widely been regarded as the triggers of the two Cretaceous global oceanic anoxic events. The premise for ascribing a causal relationship between a large igneous province and an oceanic anoxic event is their synchronicity. However, due to the detrimental effect of seawater alteration of commonly used dating materials in oceanic basalts, the ages that have been published for oceanic large igneous provinces are not all robust. Here we compile all published dating results of oceanic large igneous provinces and assess the robustness of each age data. The results show that although the quality-filtered robust ages for the large igneous provinces can provide evidence for the existence of contemporaneous eruptions with the oceanic anoxic events, the eruptive duration and tempo of the large igneous provinces remain unclear. More age data are needed to constrain the possible causal relationship between the three large igneous provinces and the two Cretaceous global oceanic anoxic events.
  • ZHANG Kaixin, HUANG Chingsheng, WANG Chen, TONG Chenchen, WANG Zicheng
    Online available: 2023-04-11
    Various models have been developed for radially divergent tracer tests in two-zone confined aquifers of the skin and formation zones. However, existing numerical solutions require considerable computing time because of the fine spatial discretization of skins. The abrupt change in parameters near the skin-formation interface produces significant errors while predicting the spatiotemporal concentration near the interface, despite fine spatial discretization. In this study, a new model was developed for conducting radially divergent tracer tests in a partially penetrating well in a two-zone-confined aquifer. The skin was treated as a new transient Robin boundary condition specified at the skin-formation interface to reflect the effect of solute adsorption/release in the
    skin and achieve no skin discretization. A finite element solution for the model was developed. The analytical solution of the model modified for full penetration of the well was developed using the Laplace transform. These results suggest that the transient Robin boundary condition leads to accurate concentration predictions affected by negative skin. The analytical solution predicts reliable ranges of 0.47~0.48 m for the skin width w and 6.4~7.7 m for the longitudinal dispersivity α'l, whereas a traditional solution exhibits a range of 0.45 m≤w≤0.54 m and 0.6 m≤α'l≤10 m. The finite element solution required only 3% of the computing time for obtaining a finite element solution based on fine skin discretization. In conclusion, this study provides implications not only
    for theoretical advances but also for useful numerical methods.
  • LI Yu, DUAN Junjie, LI Haiye, GAO Mingjun, ZHANG Yuxin, XUE Yaxin
    Online available: 2023-04-11
    Lakes play an essential role in the evolution of regional water cycles and ecosystems. In previous studies on lake evolution, most lake sediment proxy indicators have been used to reconstruct lake and climate change processes. However, there is a lack of quantitative research on the lake water cycle characteristics. Based on the water balance model for watersheds and lakes in distinct periods and the lake energy balance model based on the simulation of the transient climate, water balance calculations and lake evolution simulations for six typical lakes in the Qinghai-Tibet Plateau and its surrounding areas were carried out in this study. The results showed that the precipitation and evaporation variabilities in Xiao Qaidam Lake and Lop Nur were relatively
    small during the Holocene. The precipitation and evaporation variability in Selinco and Namco were relatively large during the early–middle Holocene and were mainly controlled by temperature and net radiation changes. The precipitation and evaporation variabilities in Qinghai Lake and Zhuyeze were similar during the early and mid–late Holocene. This study systematically analyzed and calculated the evolution of lake water cycle elements in different climatic regions of the Qinghai-Tibet Plateau during the Holocene, which will help to understand the paleoclimatic mechanism of lake evolution in this region.
  • LIU Yu, ZHANG Fengshou, SUN Jianqiang, ZHU Zhiqiang, WANG Yu, YANG Zhongkang, ZHANG Xin, GUO Zhilin, ZHANG Bo, CHEN Tao
    Online available: 2022-12-06
    We analyzed the submissions, acceptances, reviews, and grant funding of various projects of National Natural Science Foundation of China in the Environmental Geosciences in 2022 and, pointed out the issues we withfound during the submission and review processes. Moreover, wWe also summarizedd the main research progresseses and outcomes of the completed funding projects byin the Division of Environmental Geosciences completed at the end of 2021.
  • HE Jianjun, GE Fei, LIU Zhe, ZHANG Yu, GUO Yucong, LI Jing
    Online available: 2022-12-01
    The Division V (Atmospheric Discipline) of the Department of Earth Sciences, the National Natural Science Foundation of China (NSFC), successfully completed the application, review, funding and conclusion of General Program, Young Scientists Fund, and Fund for Less Developed Regions in 2022. In terms of program applications, the Division V of Department of Earth Sciences received 1817 applications for the above three types of programs in 2022, with an increase of 5.9% over 2021. Among them, 11 applications were not accepted because they did not conform to the management specifications. From the perspective of project review, the comprehensive score in 2022 is slightly higher than that in 2021. The review expert group supports original and cross research, as well as technology research and development. In terms of funding, the number of the above three types of programs funded in 2022 increased by 7.0% compared with 2021, and 11.9% for the Youth Science Foundation. From the conclusion results, 314 projects were concluded in 2021, and the indexes such as published papers were equivalent to those in previous years. In 2022, the atmospheric discipline is included in the “Responsibility, Credibility, Contribution (RCC)” evaluation mechanism reform pilot discipline. In 2022, 97.3% of review comments return on time. 81.8% of the experts believed that RCC mechanism could improve the fairness of the expert evaluation, and 90.9% of the experts believed that RCC mechanism could make the experts pay more attention to the contribution of the evaluation opinions to the applicants.
  • REN Jianguo, CHU Hang, LÜ Dawei, SUN Wenjie, SONG Huanxin, LI Suping, CAO Mingjian
    Online available: 2022-11-30
    为了有效地指导地质学科科研人员和科研单位对次年基金项目的申报,以2022 年度国家自然科学基金委员会地球科学部地质学科所管理的各类项目为研究对象,对各类项目的申请、评审和资助情况,以及4 类科学问题属性项目的申报情况进行了分析,结果显示:①与2021 年度相比,2022 年度的项目申请中,除优秀青年科学基金项目申请数下降之外,其他项目申请数都有所增加;②2022 年度面上项目、青年科学基金项目和地区科学基金项目的评审数比2021 年度略有增加。此外,对2022 年1 月提交的项目进展报告和2021 年底结题的项目结题报告进行了梳理,总结了主要学科方向取得的研究进展。
  • WANG Yongsheng, MAWeiwei, YANG Juanhao, BAI Qiao
    Online available: 2022-11-30
    Continental subduction belt are usually formed following by the development of oceanic subduction, so the information of oceanic subduction and continental subduction should be recorded in the continental orogen. The Dabie Orogen records Triassic continent-continent collision between the South China Block and the North China Block, but there is almost no evidence of oceanic subduction. Based on the speculation that rocks related to oceanic subduction may be covered at the bottom of the Hefei Basin or migrated
    to the deep mantle during continental subduction, this work carried out detailed zircon LA-ICP-MS U-Pb dating and Lu-Hf isotope analysis for the basalt and diabase in the central Hefei Basin. The result show that both the diabase from the Dashushan and the basalt from the Xiaoshushan have obtained much late Paleozoic zircon ages, with the weighted average age of 338, 270 Ma and 349, 273 Ma, while the diabase from the Jimingshan is mainly of Early Cretaceous zircon ages. The zircon ages in these mafic igneous rocks are characterized by continuous distribution from the Paleoproterozoic to the Cretaceous. The two smallest ages indicate the time of the Cenozoic mafic magmatism, and other zircons are come from the recycling of ancient rocks. Based on the comprehensive analysis of zircon preservation under high temperature conditions and their source,it can be concluded that the late Paleozoic zircon in the Cenozoic mafic igneous rocks of the Hefei Basin comes from the magmatic rocks formed by the subduction of the PaleoTethys ocean. During the Triassic continent-continent subduction, the Paleozoic magmatic rocks were partly transported to the mantle depth, and then partially melted with the mantle during the subduction of the Cenozoic Pacific plate to form the Cenozoic mafic igneous rocks. This provides direct evidence for the occurrence of late Paleozoic oceanic subduction in the Dabie Orogen.
  • XIONG Juhua, GAO Yang, WU Hao, LI Xin, LIANG Dan, YU Wenping, MAMeihong, ZHOU Yongqiang, WANG Xiaofeng
    Online available: 2022-11-25
    National Natural Science Foundation of China (NSFC) receives widespread attentions and is the main funding institution of fundamental research in China. The submission and reception of proposals to the Division of Geography of the Department of Earth Sciences of the National Natural Science Foundation of China in 2022 were introduced in this manuscript. The analysis of the proposal reviews and grant funding processes was presented from three subdisciplines that were Physical Geography, Human Geography and Geographic
    Informatics, three types of projects that were General program, Young Scientists Funding Program and Regional Funding Project, and four types of attributes of scientific issues formulated by NSFC. Additionally, issues to be noted in the proposal submission and peer review were pointed out. For the funded projects at the end of 2021, firstly, we analyzed the closeout achievement of various projects, secondly, we focused on the representative achievements and, finally, we pointed the main problems in the project progress report and closing report.
  • LI Wei, XIAO Jun, HAO Lulu, HU Dongmei
    Online available: 2022-11-25
    We summarized the application, peer review, and acceptance of projects managed by Division of Geochemistry (D03), Department of Earth Sciences, National Natural Science Foundation of China in 2022, and introduced the research advances of completed projects in 2021. The results are: ① In 2022, the number of project applications for the discipline of geochemistry remains constant; ② The application formats have been improved and the rates of applications passing preliminary examination are significantly higher than ever before; ③ The submission rates of the General Program, Young Scientists Fund and Fund for Less Developed Regions
    exceed 143.5%; ④ By piloting the mechanism of “Responsibility, Credibility, Contribution” within three years, the Division of Geochemistry has recorded the attitude, justice and contributions of ca. 2000 peer-review experts, in order to explore how to better play the central role of peer-review in funding decisions;⑤ Significant progress have been made in Isotopic Geochemistry, Elemental Geochemistry, Geochronology, and Cosmochemistry in 2021.
  • LENG Shuying, ZHANG Liang, WU Renhao, WANG Lifang, WANG Hui, LE Chengfeng
    Online available: 2022-11-18
    To better understand the application situation for researchers, and further to improve the quality of proposals and final report of funded projects, this paper analyzed the situation of application, review and funded proposals in the fourth division in Earth Science Department (i. e., Ocean and Polar Science Division), sorted problems during proposal acceptance and external review process, and summarized the performance of funded projects ended in 2021. Comparing to 2021, five more institutions submitted General projects,Youth science funding,and Funding for Less Developed Regions proposals to the Ocean and Polar Science Division. The application number for all the three kinds funding increased, with increasing rate of
    13.8%, 10.4%, and 10.6%, respectively, wherein the subcode of D0611 (Ocean Engineering and Environmental Responding ) and D0613 (Oceanic Energy and Resource) have the highest increase rate. The number of application belongs to original innovation and interdisciplinary category increased, however, their ratio slightly decreased. The final report of funded projects ended in 2021 has issues such as insufficient summarization and low ratio of first acknowledgement of the funded project.
  • Huang Ping, ZhouShijie
    Advances in Earth Science.
    Online available: 2018-11-07
    Since tropical rainfall is important in the global energy and hydrologic cycle, the tropical rainfall changes under global warming arise extensive attention around the world in recent decades. The advances in the observational studies and model projection for the tropical rainfall changes under global warming are reviewed here. The frontiers in the mechanism of regional tropical rainfall changes and the approaches of rainfall change research are summarized. The large intermodel spread in the multi-model projections, the sources of uncertainty and the methods to reduce the uncertainty are also introduced. In the last, the challenges about the tropical rainfall changes are discussed.
  • He Yinjie, Wu Da fang, Liu Yan yan
    Advances in Earth Science.
    Online available: 2018-11-07
     The public rail transport system in cities can promote physical urban transition, resulting in land use and land cover change, changing the public daily behaviors and consequently bringing huge economic benefits to its imminent areas. Based on statistical analysis and visualization tools, this study, used Citespace and Google Earth, explored approximately 455 papers from Web of Science and 321 papers from CNKI, to obtain current research trends in assessments of the impacts of public rail transport on land use change. The literature classification, organization and comments on such current studies and hot research topics are valuable for future research. Three conclusions were then drawn: First of all, similar topics have been done by both domestic and oversea scholars, but from slightly different perspective and at different scales. Secondly, public rail transport often caused increasing in housing price for both residential and commercial blocks; the influence on population density is more significant in the outskirts than the counterparts of downtown areas, but the influence often emerged with a with a unfixed time lag. Thirdly, RS,GIS and GPS(3S) techniques are a promising tools for the research of the impacts of public rail transport on land use change in the era of "big data". Based on the conclusions, four suggestions are proposed: Firstly, future research in this field will be more comprehensive and humanistic studies. Secondly, oversea development models could not be fully applied in China, and thus corresponding improvements with China’s situation are required. Thirdly, theoretically speaking, bicycle sharing can expand the service range of public rail transport. Fourthly, reasonable buffers are important to obtain fine statistical area of land change affected by public rail transport.
  • Chen Kegui, Liu Sixu, Wang Zhaofeng, Zhang Yifei
    Advances in Earth Science.
    Online available: 2018-11-07
    The basement carbonate reservoirs, in the Karabulak oilfield of the Southern Turgay basin, have the characteristics of complex structure, variety of pore type and strong heterogeneity. And the identification of such reservoirs by single conventional logging method is always a difficult point in logging interpretation. In this paper, the response characteristics of conventional logging curves such as deep lateral resistivity, acoustic time difference, density and compensated neutron are used for reconstruction. Combined with the improved method of curve change rate, the response laws of fractured carbonate reservoirs, pore-cave reservoirs and fractured vuggy reservoirs on conventional logging curves are summed up respectively. And a new logging evaluation method for carbonate fractured vuggy reservoirs in the Karabulak oilfield of South Turgay basin is proposed. This method is used to identify reservoirs in K8 and K34 wells of this oilfield. The results show that the carbonate reservoirs in this area are mainly fractured-vuggy  type. Compared with the oil test conclusion and imaging logging, the method proposed in this paper accurately divided the reservoir type. And the efficiency and accuracy of the reservoir division have been greatly improved.

  • Li Yongtao, Li Jianwen, Pan Lin, Guo Liangliang, Wei Rongrong, Liu Dezhi
    Advances in Earth Science.
    Online available: 2018-11-07
    With the successful launch of the 16 MEO satellites of the Beidou-3 global satellite navigation system and the broadcast of new signals, Beidou officially entered the global construction stage, while the international GNSS monitoring and assessment system (iGMAS) is also performing systematic testing and evaluation on various aspects of operational performance from satellite end to ground receiving end of Beidou-3 system. This paper analyzes and evaluates the observation quality of new signals B1C and B2a broadcasted by the 12 new Beidou-3 MEO satellites on the observation data integrity rate, multipath error, pseudorange noise and carrier-to-noise ratio (CNR) compared with GPS and GALILEO. The results show that the observation data integrity rate of B1C signal is better than that of B2a signal in the Beidou-3 system. In the aspects of multipath error, pseudorange noise and CNR, B2a signal are better than B1C. The performances of the 12 MEO satellites of Beidou-3 are equivalent, that is, Beidou-3 the consistency of satellites can be guatenteed. In terms of pseudo-range noise, Beidou-3 is slightly worse than GPS and GALILEO While the observation data integrity rate, multipath error and CNR of Beidou-3 are equivalent to GPS and GALILEO.
  • Zhang Shuo, Jian Xing, Zhang Wei
    Advances in Earth Science.
    Online available: 2018-11-07
    In situ analysis of detrital apatite is a significant approach to sedimentary provenance analysis, which is an important aspect in sedimentary geology study. Several trace elements such as Sr, Y and rare earth elements (REEs) concentrate in apatites, and the distribution of these elements is depended on the content of SiO2 and the distribution coefficient of the melt, thus the trace element abundances is obviously different in different rocks. These features can be used to indicate parent-rocks of detrital apatites in sedimentary rocks. The approaches and proxies of detrital apatite to sedimentary provenance analysis can be summarized as follows. ①elemental geochemistry, such as Sr, Y, REEs, the approaches include chondrite-normalised REE distribution patterns of apatites, classification and regression tree (CART) and discriminant plots of REEparameters ; ②isotopic geochemistry, including Sr-Nd and Lu-Hf isotopes; ③Multi-dating , including low-temperature t thermochronology such as (U-Th)/He (AHe)and fission track (AFT) dating, and high-temperature thermochronology such as U-Pb dating. Based on an integrated analysis using these methods, we can get various and comprehensive geological information such as the rock type, formation conditions and evolution of source rocks, the history of uplift and exhumation of source areas and even the subsidence history of sedimentary basins. Although the low-temperature thermochronology of detrital apatite is widely used in sedimentary provenance analysis, the elemental and isotopic geochemistry, as well as the U-Pb dating, remain to be developed and. These approaches are supposed to have wide application prospects in several research areas such as tectonics, sedimentary geology basin analysis and even paleoclimatology.
  • Ma Qianhong, Zhang Keli
    Advances in Earth Science.
    Online available: 2018-11-07
    The karst area of Southwest China is suffering from serious ecological and environmental problems due to soil erosion, while the research on soil erosion is not sufficient. Primary achievement had been systematically reviewed in this paper in three aspects: erosion characteristics, current researches about erosion on different spatial scales, key scientific problems. Based on the review, the authors figured out the shortcomings of the existing studies and pointed out the directions on erosion study in southwest karst region. The results showed that: (1) Due to the existence of a dual structure in karst environment including ground and underground erosion, the process of runoff and sediment production on slope scale and confluence and sediment transportation processes on catchment scale were more complex under the unique geological and hydrological backgrounds; (2) At present, most researches about erosion mechanism in karst area focused on slope scale and some achievement on quantitative evaluation of erosion factors was made. While continuous data with high quality about relationship between water and sediment on catchment scale was limited. When data was scarce, river sediment data could be used as an effective way to study soil erosion intensity and spatial and temporal variation in karst area; (3) It is more reasonable to use 50 t/(km2·a) as the grading standard of soil loss tolerance than the previous grading standard of soil erosion intensity. Given the complex relationship between rocky desertification and soil erosion, more quantitative studies about the effects of rocky desertification on soil erosion were still necessary. There were different viewpoints on soil leakage definitions, the leakage mechanism and soil leakage ratios, and new breakthroughs could be achieved by combining different methods and matching multi-scales. In conclusion, in order to further reveal the soil erosion laws and establish and revise available regional soil erosion forecasting models for Southwest karst areas, synchronous test and monitoring on slope, watershed, and channel spatial scales were urgently needed. The results could provide theoretical and technical support for promoting soil and water conservation works for the karst area of Southwest China.
  • Chen Qilin, Huang Chenggang
    Advances in Earth Science.
    Online available: 2018-11-07
    With the deepening of exploration degree, the progress of exploration technology and the increasing demands for oil and gas resources, some deep buried reservoirs with relatively poor physical properties have attracted more and more attention of geologists. After decades of exploration, many high-quality reservoirs with shallow burial and well-preserved primary pores have been widely discovered and put into production. However, deep buried tight reservoirs with secondary dissolved pores as the main reservoir space are increasingly becoming the focus of exploration in mature exploration areas. Therefore, searching for secondary pore development zones and dissolved “sweet” reservoirs will become an important new field for fine exploration in the future. Based on some typical case study and a large number of research results, this paper systematically expounded the modification of reservoirs by dissolution from the following four aspects:① diagenetic stage of dissolution; ②types of dissolution fluids;③main controlling factors of dissolution; ④ effect of dissolution on reservoir modification. In recent years, more and more research achievements have made important progress in dissolution mechanism and reservoir modification effect. The systematic analysis of these mainstream views has some reference value for similar geological conditions in the future.