The November 1948 open session of the Institute of Geological Sciences AS USSR was previously unknown,in contrast to the August 1948 session of VASKhNIL.The publication of the transcript of the session of geologists i...The November 1948 open session of the Institute of Geological Sciences AS USSR was previously unknown,in contrast to the August 1948 session of VASKhNIL.The publication of the transcript of the session of geologists is based on the original verified transcript from the Geological Institute and the Archive RAS.It presented reports on the main scientific directions of geology:stratigraphy,the Quaternary geology,lithology,geotectonics,petrography and petrology,mineralogy and geochemistry,and the geology of ore and coal deposits.This thick book details all the Q&A sessions,discussions of theories,methods,and practice among the leading Soviet geoscientists.The session and its resolution describe the situation and development of geology in the USSR in the mid-twentieth century as well as the collateral impact of the Lysenko affair on the earth sciences in the USSR.展开更多
Coptotettix acutiangulus Zha sp. nov. from northern Thailand is described and illustrated with photographs. Morphological differences with a similar species C. annandalei are described in detail. C. acutiangulus Zha s...Coptotettix acutiangulus Zha sp. nov. from northern Thailand is described and illustrated with photographs. Morphological differences with a similar species C. annandalei are described in detail. C. acutiangulus Zha sp. nov. may be potentially distributed in Nepal. A brief discussion of the ecology and habitat of C. acutiangulus is given.展开更多
Although the Suidae animals were one of the most prosperous mammals, their taxa and phylogeny were poorly studied. To bridge this research gap, the complete mitochondrial DNA cyt b sequences (1140 bp)of one red rive...Although the Suidae animals were one of the most prosperous mammals, their taxa and phylogeny were poorly studied. To bridge this research gap, the complete mitochondrial DNA cyt b sequences (1140 bp)of one red river pig ( Potamochoerus porcus ), one bearded pig ( Sus barbatus ), and several Eurasian wild boars ( Sus scorfa ) were determined with direct PCR sequencing method. Incorporated with the sequences of other Suidae species obtained from GenBank, the phylogentic trees of Suidae species were constructed by Neighbor-Joining and Most Parsimony method. Our resuits showed that the babirousa was sister group of all other species. The African species clustered into a single clade, while the Eurasian species formed the other clade. The phylogenetic positions of the Sus species were consistent with their geographical distribution. Based on our phylogeographical results, the Sus species could be classified into three groups: (1) the relatively primitive animals from Philippine Islands (such as S. cebifrons and S. philippensis ), Sulawesi and it's adjacent islands (S. celebensis), (2) the Eurasian wild boars (S. scrofa and the mysterious S. salvanius), and (3) other pigs (such as S. barbatus and S. verrucosus), which might further diverged as the islands type (such as S. barbatus from Sumatra and Borneo) and the continental type (such as Malay Peninsula wild boar).展开更多
Engineering excavation GIS (E 2 GIS) is a real-3D GIS serving for geosciences related to geo-engineering, civil engineering and mining engineering based on generalized tri-prism (GTP) model. As two instances of GTP mo...Engineering excavation GIS (E 2 GIS) is a real-3D GIS serving for geosciences related to geo-engineering, civil engineering and mining engineering based on generalized tri-prism (GTP) model. As two instances of GTP model, G\|GTP is used for the real\|3D modeling of subsurface geological bodies, and E\|GTP is used for the real\|3D modeling of subsurface engineering excavations.In the light of the discussions on the features and functions of E 2 GIS, the modeling principles of G\|GTP and E\|GTP are introduced. The two models couple together seamlessly to form an integral model for subsurface spatial objects including both geological bodies and excavations. An object\|oriented integral real\|3D data model and integral spatial topological relations are discussed.展开更多
3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geo...3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geological faults in 3D is currently a topical research area. Structural modeling techniques of complex geological entities contain- ing reverse faults are discussed and a series of approaches are proposed. The geological concepts involved in computer modeling and visualization of geological fault in 3D are explained, the type of data of geological faults based on geo- logical exploration is analyzed, and a normative database format for geological faults is designed. Two kinds of model- ing approaches for faults are compared: a modeling technique of faults based on stratum recovery and a modeling tech- nique of faults based on interpolation in subareas. A novel approach, called the Unified Modeling Technique for stratum and fault, is presented to solve the puzzling problems of reverse faults, syn-sedimentary faults and faults terminated within geological models. A case study of a fault model of bed rock in the Beijing Olympic Green District is presented in order to show the practical result of this method. The principle and the process of computer modeling of geological faults in 3D are discussed and a series of applied technical proposals established. It strengthens our profound compre- hension of geological phenomena and the modeling approach, and establishes the basic techniques of 3D geological modeling for practical applications in the field of geosciences.展开更多
Land surface models are often highly nonlinear with model physics that contain parameterized discontinuities. These model attributes severely limit the application of advanced variational data assimilation methods int...Land surface models are often highly nonlinear with model physics that contain parameterized discontinuities. These model attributes severely limit the application of advanced variational data assimilation methods into land data assimilation. The ensemble Kalman filter (EnKF) has been widely employed for land data assimilation because of its simple conceptual formulation and relative ease of implementation. An updated ensemble-based three-dimensional variational assimilation (En3-DVar) method is proposed for land data assimilation.This new method incorporates Monte Carlo sampling strategies into the 3-D variational data assimilation framework. The proper orthogonal decomposition (POD) technique is used to efficiently approximate a forecast ensemble produced by the Monte Carlo method in a 3-D space that uses a set of base vectors that span the ensemble. The data assimilation process is thus significantly simplified. Our assimilation experiments indicate that this new En3-DVar method considerably outperforms the EnKF method by increasing assimilation precision. Furthermore, computational costs for the new En3-DVar method are much lower than for the EnKF method.展开更多
The problem of taking an unorganized point cloud in 3D space and fitting a polyhedral surface to those points is both important and difficult. Aiming at increasing applications of full three dimensional digital terrai...The problem of taking an unorganized point cloud in 3D space and fitting a polyhedral surface to those points is both important and difficult. Aiming at increasing applications of full three dimensional digital terrain surface modeling, a new algorithm for the automatic generation of three dimensional triangulated irregular network from a point cloud is pro- posed. Based on the local topological consistency test, a combined algorithm of constrained 3D Delaunay triangulation and region-growing is extended to ensure topologically correct reconstruction. This paper also introduced an efficient neighbor- ing triangle location method by making full use of the surface normal information. Experimental results prove that this algo- rithm can efficiently obtain the most reasonable reconstructed mesh surface with arbitrary topology, wherein the automati- cally reconstructed surface has only small topological difference from the true surface. This algorithm has potential applica- tions to virtual environments, computer vision, and so on.展开更多
Based on the daily maximum air temperature data from 300 stations in China from 1958 to 2008, the climatological distribution of the number of days with high temperature extremes (HTEs, maximum temperatures higher th...Based on the daily maximum air temperature data from 300 stations in China from 1958 to 2008, the climatological distribution of the number of days with high temperature extremes (HTEs, maximum temperatures higher than 35℃) are studied with a focus on the long-term trends. Although the number of HTE days display well-defined sandwich spatial structures with significant decreasing trends in central China and increasing trends in northern China and southern China, the authors show that the decrease of HTE days in central China occurs mainly in the early period before the 1980s, and a significant increase of HTE days dominates most of the stations after the 1980s. The authors also reveal that there is a jump-like acceleration in the number of HTE days at most stations across China since the mid 1990s, especially in South China, East China, North China, and northwest China.展开更多
Geopotential, dynamic, orthometric and normal height systems and the corrections related to these systems are evaluated in this paper. Along two different routes, with a length of about 5 kilometers, precise leveling ...Geopotential, dynamic, orthometric and normal height systems and the corrections related to these systems are evaluated in this paper. Along two different routes, with a length of about 5 kilometers, precise leveling and gravity measurements are done. One of the routes is in an even field while the other is in a rough field. The magnitudes of orthometric, normal and dynamic corrections are calculated for each route. Orthometric, dynamic, and normal height differences are acquired by adding the corrections to the height differences obtained from geometric leveling. The magnitudes of the corrections between the two routes are compared. In addition, by subtracting orthometric, dynamic, and normal heights from geometric leveling, deviations of these heights from geometric leveling are counted.展开更多
In this paper, a new polychaete species, Eranno carrerai sp. nov. from coastal areas of China, is described based on specimens deposited in the Marine Biological Museum of the Chinese Academy of Sciences, Qingdao, col...In this paper, a new polychaete species, Eranno carrerai sp. nov. from coastal areas of China, is described based on specimens deposited in the Marine Biological Museum of the Chinese Academy of Sciences, Qingdao, collected during 1957 to 1976 from the Yellow Sea, East China Sea and South China Sea at depths of 9–210 m.展开更多
Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS...Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS) in an attempt to understand the processes that control their behavior. Glaciers over the recent 40 years(1970-2010) have shrunk 3.4±3.1%in area, based on a comparison between two Chinese glacier inventories. Variations of surface elevations, derived from ICESat-GLAS(Ice, Cloud, and Land Elevation Satellite-Geoscience Laser Altimeter System) elevation products(GLA14 data) using the robust linear-fit method, indicate that the glaciers have been gaining mass at a rate of 0.23±0.24 m w.e./a since 2003. The annual mass budget for the whole WKS range from 2003 to 2009 is estimated to be 0.71±0.62 Gt/a. This gain trend is confirmed by MOD10A1 albedo for the WKS region which shows a descent of the mean snowline altitude from 2003 to 2009.展开更多
To examine the zonal asymmetry of the Antarctic oscillation (AAO), different portions of the AAO from June to October (JJASO) in the interannual variability of the Atlantic tropical hurricanes number (ATHN) are docume...To examine the zonal asymmetry of the Antarctic oscillation (AAO), different portions of the AAO from June to October (JJASO) in the interannual variability of the Atlantic tropical hurricanes number (ATHN) are documented in this research. It follows that the AAO in the Western Hemisphere (AAOWH) is positively correlated with the ATHN, at 0.36 during the period of 1871-1998 and 0.42 during the period of 1949-98. After removing the linear regressions on the Southern Oscillation Index (SOI) in all time series, the above correlation coefficients are 0.25 and 0.30, respectively. The underlying mechanisms are studied through analyses of the atmospheric general circulation variability associated with the AAOWH. It turns out that the positive (negative) phase of JJASO AAOWH corresponds with several factors: decreased (increased) vertical zonal wind shear magnitude, low-level anomalous convergence (divergence), high-level anomalous divergence (convergence), and warmed (cooled) sea surface temperature in the tropical Atlantic. Therefore, the positive (negative) phase of JJASO AAOWH is favorable (unfavorable) to the tropical hurricane genesis.展开更多
The validity measurement of fuzzy clustering is a key problem. If clustering is formed, it needs a kind of machine to verify its validity. To make mining more accountable, comprehensible and with a usable spatial patt...The validity measurement of fuzzy clustering is a key problem. If clustering is formed, it needs a kind of machine to verify its validity. To make mining more accountable, comprehensible and with a usable spatial pattern, it is necessary to first detect whether the data set has a clustered structure or not before clustering. This paper discusses a detection method for clustered patterns and a fuzzy clustering algorithm, and studies the validity function of the result produced by fuzzy clustering based on two aspects, which reflect the un-certainty of classification during fuzzy partition and spatial location features of spatial data, and proposes a new validity function of fuzzy clustering for spatial data. The experimental result indicates that the new validity function can accurately measure the validity of the results of fuzzy clustering. Especially, for the result of fuzzy clustering of spatial data, it is robust and its classification result is better when compared to other indices.展开更多
The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape c...The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape classification system is an important scientific basis for landscape protection and tourism development in this region. By combining geology and geography and referring to the concepts of "system tract" and "tectonic system" in geology, this paper comes up with grading standards for the geoscience landscape system of this region. Based on the regional stratigraphic structure, tectonic fault marks and geomorphological differentiation, this paper comes up with 2 Grade Ⅰ geoscience landscape system tracts, 8 Grade Ⅱ geoscience landscape systems, 21 Grade Ⅲ geoscience landscape areas, and 165 representative Grade Ⅳ geoscience landscape attractions. According to the main classification methods for the geological heritage and tourism landscapes, the geoscience landscapes can be divided into 4 categories, 16 types and 19 subtypes. On this basis, 23 eco-tourism areas of the mid-southern section of the Hengduan Mountains can be delimited. The study provides a theoretical direction and method reference for the geoscience landscape division and tourism zonation, which has an importantsignificance on the mountain landscape protection and tourism development in the regions of complex geo-environments.展开更多
One of the core developments in geomathematics in now days is the use of digital data processing in mineral prospecting and assessment. The information discovery is based on multidisciplinary geoscientific data and an...One of the core developments in geomathematics in now days is the use of digital data processing in mineral prospecting and assessment. The information discovery is based on multidisciplinary geoscientific data and an integrated management approach is crucial. The lack of a standard description hinders interoperations in database search and discovery. Metadata hierarchy aims to provide a standard view of the geoscientific data, and facilitate data description and discovery. In the research of integrated geoscientific database, the metadata hierarchy used a standardized description for each collection in the content structure and realized in semantic structure. It recorded both dataset identification and inner structures and relationships of objects, thus differed from many other applications. There were four tiers in the content structure and three levels in the semantic structure. With its help, database users could determine how applicable a dataset is to a project, and improve their queries to the database. Effectiveness of data accessing is significantly enhanced through the rich, consistent metadata.展开更多
Similarity relation is one of the spatial relations in the community of geographic information science and cartography.It is widely used in the retrieval of spatial databases, the recognition of spatial objects from i...Similarity relation is one of the spatial relations in the community of geographic information science and cartography.It is widely used in the retrieval of spatial databases, the recognition of spatial objects from images, and the description of spatial features on maps.However, little achievements have been made for it by far.In this paper, spatial similarity relation was put forward with the introduction of automated map generalization in the construction of multi-scale map databases;then the definition of spatial similarity relations was presented based on set theory, the concept of spatial similarity degree was given, and the characteristics of spatial similarity were discussed in detail, in-cluding reflexivity, symmetry, non-transitivity, self-similarity in multi-scale spaces, and scale-dependence.Finally a classification system for spatial similarity relations in multi-scale map spaces was addressed.This research may be useful to automated map generalization, spatial similarity retrieval and spatial reasoning.展开更多
Trends in six indices of precipitation in China for seasons during 1961-2007 were analyzed based on daily observations at 587 stations. The trends were estimated by using Sen's method with Mann-Kendall's test ...Trends in six indices of precipitation in China for seasons during 1961-2007 were analyzed based on daily observations at 587 stations. The trends were estimated by using Sen's method with Mann-Kendall's test for quantifying the significance. The geographical patterns of trends in the seasonal indices of extremes were similar to those of total precipitation. For winter, both total and extreme precipitation increased over nearly all of China, except for a small part of northern China. Increasing trends in extreme precipitation also occurred at many stations in southwestern China for spring and the midlower reaches of the Yangtze River and southern China for summer. For autumn, precipitation decreased in eastern China, with an increasing length of maximum dry spell, implying a drying tendency for the post-rainy season. Wetting trends have prevailed in most of western China for all seasons. The well-known 'flood in the south and drought in the north' trend exists in eastern China for summer, while a nearly opposite trend pattern exist for spring.展开更多
文摘The November 1948 open session of the Institute of Geological Sciences AS USSR was previously unknown,in contrast to the August 1948 session of VASKhNIL.The publication of the transcript of the session of geologists is based on the original verified transcript from the Geological Institute and the Archive RAS.It presented reports on the main scientific directions of geology:stratigraphy,the Quaternary geology,lithology,geotectonics,petrography and petrology,mineralogy and geochemistry,and the geology of ore and coal deposits.This thick book details all the Q&A sessions,discussions of theories,methods,and practice among the leading Soviet geoscientists.The session and its resolution describe the situation and development of geology in the USSR in the mid-twentieth century as well as the collateral impact of the Lysenko affair on the earth sciences in the USSR.
基金supported by the National Natural Science Foundation of China(31460012)the Modernization of Traditional Chinese Medicine Program of Guizhou Province([2012]5008)
文摘Coptotettix acutiangulus Zha sp. nov. from northern Thailand is described and illustrated with photographs. Morphological differences with a similar species C. annandalei are described in detail. C. acutiangulus Zha sp. nov. may be potentially distributed in Nepal. A brief discussion of the ecology and habitat of C. acutiangulus is given.
文摘Although the Suidae animals were one of the most prosperous mammals, their taxa and phylogeny were poorly studied. To bridge this research gap, the complete mitochondrial DNA cyt b sequences (1140 bp)of one red river pig ( Potamochoerus porcus ), one bearded pig ( Sus barbatus ), and several Eurasian wild boars ( Sus scorfa ) were determined with direct PCR sequencing method. Incorporated with the sequences of other Suidae species obtained from GenBank, the phylogentic trees of Suidae species were constructed by Neighbor-Joining and Most Parsimony method. Our resuits showed that the babirousa was sister group of all other species. The African species clustered into a single clade, while the Eurasian species formed the other clade. The phylogenetic positions of the Sus species were consistent with their geographical distribution. Based on our phylogeographical results, the Sus species could be classified into three groups: (1) the relatively primitive animals from Philippine Islands (such as S. cebifrons and S. philippensis ), Sulawesi and it's adjacent islands (S. celebensis), (2) the Eurasian wild boars (S. scrofa and the mysterious S. salvanius), and (3) other pigs (such as S. barbatus and S. verrucosus), which might further diverged as the islands type (such as S. barbatus from Sumatra and Borneo) and the continental type (such as Malay Peninsula wild boar).
文摘Engineering excavation GIS (E 2 GIS) is a real-3D GIS serving for geosciences related to geo-engineering, civil engineering and mining engineering based on generalized tri-prism (GTP) model. As two instances of GTP model, G\|GTP is used for the real\|3D modeling of subsurface geological bodies, and E\|GTP is used for the real\|3D modeling of subsurface engineering excavations.In the light of the discussions on the features and functions of E 2 GIS, the modeling principles of G\|GTP and E\|GTP are introduced. The two models couple together seamlessly to form an integral model for subsurface spatial objects including both geological bodies and excavations. An object\|oriented integral real\|3D data model and integral spatial topological relations are discussed.
基金Project 2001AA135170 supported by the National High-Tech Research and Development (863) Program of China and 06ZR14031 by the Natural ScienceFoundation of Shanghai Municipality
文摘3D geological modeling, one of the most important applications in geosciences of 3D GIS, forms the basis and is a prerequisite for visualized representation and analysis of 3D geological data. Computer modeling of geological faults in 3D is currently a topical research area. Structural modeling techniques of complex geological entities contain- ing reverse faults are discussed and a series of approaches are proposed. The geological concepts involved in computer modeling and visualization of geological fault in 3D are explained, the type of data of geological faults based on geo- logical exploration is analyzed, and a normative database format for geological faults is designed. Two kinds of model- ing approaches for faults are compared: a modeling technique of faults based on stratum recovery and a modeling tech- nique of faults based on interpolation in subareas. A novel approach, called the Unified Modeling Technique for stratum and fault, is presented to solve the puzzling problems of reverse faults, syn-sedimentary faults and faults terminated within geological models. A case study of a fault model of bed rock in the Beijing Olympic Green District is presented in order to show the practical result of this method. The principle and the process of computer modeling of geological faults in 3D are discussed and a series of applied technical proposals established. It strengthens our profound compre- hension of geological phenomena and the modeling approach, and establishes the basic techniques of 3D geological modeling for practical applications in the field of geosciences.
基金supported by the National Natural Science Foundation of China (Grant No. 40705035)the National High Technology Research and Development Program of China (863 Program) (Grant Nos. 2009AA12Z129 and 2007AA12Z144)
文摘Land surface models are often highly nonlinear with model physics that contain parameterized discontinuities. These model attributes severely limit the application of advanced variational data assimilation methods into land data assimilation. The ensemble Kalman filter (EnKF) has been widely employed for land data assimilation because of its simple conceptual formulation and relative ease of implementation. An updated ensemble-based three-dimensional variational assimilation (En3-DVar) method is proposed for land data assimilation.This new method incorporates Monte Carlo sampling strategies into the 3-D variational data assimilation framework. The proper orthogonal decomposition (POD) technique is used to efficiently approximate a forecast ensemble produced by the Monte Carlo method in a 3-D space that uses a set of base vectors that span the ensemble. The data assimilation process is thus significantly simplified. Our assimilation experiments indicate that this new En3-DVar method considerably outperforms the EnKF method by increasing assimilation precision. Furthermore, computational costs for the new En3-DVar method are much lower than for the EnKF method.
基金Supported by the National Natural Science Foundation of China (No.40671158), the National 863 Program of China(No.2006AA12Z224) and the Program for New Century Excellent Talents in University (No.NCET-05-0626).
文摘The problem of taking an unorganized point cloud in 3D space and fitting a polyhedral surface to those points is both important and difficult. Aiming at increasing applications of full three dimensional digital terrain surface modeling, a new algorithm for the automatic generation of three dimensional triangulated irregular network from a point cloud is pro- posed. Based on the local topological consistency test, a combined algorithm of constrained 3D Delaunay triangulation and region-growing is extended to ensure topologically correct reconstruction. This paper also introduced an efficient neighbor- ing triangle location method by making full use of the surface normal information. Experimental results prove that this algo- rithm can efficiently obtain the most reasonable reconstructed mesh surface with arbitrary topology, wherein the automati- cally reconstructed surface has only small topological difference from the true surface. This algorithm has potential applica- tions to virtual environments, computer vision, and so on.
基金supported by the National Basic Research Program of China under Grant No. 2009CB421405the National Natural Science Foundation of China under Grant No. 40775035the Innovation Project of Chinese Academy of Sciences under Grant No. 076607M301
文摘Based on the daily maximum air temperature data from 300 stations in China from 1958 to 2008, the climatological distribution of the number of days with high temperature extremes (HTEs, maximum temperatures higher than 35℃) are studied with a focus on the long-term trends. Although the number of HTE days display well-defined sandwich spatial structures with significant decreasing trends in central China and increasing trends in northern China and southern China, the authors show that the decrease of HTE days in central China occurs mainly in the early period before the 1980s, and a significant increase of HTE days dominates most of the stations after the 1980s. The authors also reveal that there is a jump-like acceleration in the number of HTE days at most stations across China since the mid 1990s, especially in South China, East China, North China, and northwest China.
文摘Geopotential, dynamic, orthometric and normal height systems and the corrections related to these systems are evaluated in this paper. Along two different routes, with a length of about 5 kilometers, precise leveling and gravity measurements are done. One of the routes is in an even field while the other is in a rough field. The magnitudes of orthometric, normal and dynamic corrections are calculated for each route. Orthometric, dynamic, and normal height differences are acquired by adding the corrections to the height differences obtained from geometric leveling. The magnitudes of the corrections between the two routes are compared. In addition, by subtracting orthometric, dynamic, and normal heights from geometric leveling, deviations of these heights from geometric leveling are counted.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.IOCAS O72715)
文摘In this paper, a new polychaete species, Eranno carrerai sp. nov. from coastal areas of China, is described based on specimens deposited in the Marine Biological Museum of the Chinese Academy of Sciences, Qingdao, collected during 1957 to 1976 from the Yellow Sea, East China Sea and South China Sea at depths of 9–210 m.
基金supported by a National Science Foundation of China major project (Grant No. 41190084) funded by the National Natural Science Foundation of Chinathe National Key Technology R&D Program (Grant No. 2012BAC19B07)+2 种基金the International S&T Cooperation Program of the Ministry of Science and Technology of China (Grant No. 2010DFA92720-23)provided by the MOST (Grant No. 2006FY110200)CAS projects (Grant No. KZCX2-YW-301)
文摘Recent studies on glaciers in the West Kunlun Shan, northwest Tibetan Plateau, have shown that they may be stable or retreating slightly. Here, we assess changes in the mass of the glaciers in the West Kunlun Shan(WKS) in an attempt to understand the processes that control their behavior. Glaciers over the recent 40 years(1970-2010) have shrunk 3.4±3.1%in area, based on a comparison between two Chinese glacier inventories. Variations of surface elevations, derived from ICESat-GLAS(Ice, Cloud, and Land Elevation Satellite-Geoscience Laser Altimeter System) elevation products(GLA14 data) using the robust linear-fit method, indicate that the glaciers have been gaining mass at a rate of 0.23±0.24 m w.e./a since 2003. The annual mass budget for the whole WKS range from 2003 to 2009 is estimated to be 0.71±0.62 Gt/a. This gain trend is confirmed by MOD10A1 albedo for the WKS region which shows a descent of the mean snowline altitude from 2003 to 2009.
基金supported by the National Natural Science Foundation of China, under Grant No. 40775049the Major State Basic Research Development Program of China (973 Program), under Grant No. 2009CB421406the IAP Key Innovation Programs IAP07117 and IAP09302
文摘To examine the zonal asymmetry of the Antarctic oscillation (AAO), different portions of the AAO from June to October (JJASO) in the interannual variability of the Atlantic tropical hurricanes number (ATHN) are documented in this research. It follows that the AAO in the Western Hemisphere (AAOWH) is positively correlated with the ATHN, at 0.36 during the period of 1871-1998 and 0.42 during the period of 1949-98. After removing the linear regressions on the Southern Oscillation Index (SOI) in all time series, the above correlation coefficients are 0.25 and 0.30, respectively. The underlying mechanisms are studied through analyses of the atmospheric general circulation variability associated with the AAOWH. It turns out that the positive (negative) phase of JJASO AAOWH corresponds with several factors: decreased (increased) vertical zonal wind shear magnitude, low-level anomalous convergence (divergence), high-level anomalous divergence (convergence), and warmed (cooled) sea surface temperature in the tropical Atlantic. Therefore, the positive (negative) phase of JJASO AAOWH is favorable (unfavorable) to the tropical hurricane genesis.
文摘The validity measurement of fuzzy clustering is a key problem. If clustering is formed, it needs a kind of machine to verify its validity. To make mining more accountable, comprehensible and with a usable spatial pattern, it is necessary to first detect whether the data set has a clustered structure or not before clustering. This paper discusses a detection method for clustered patterns and a fuzzy clustering algorithm, and studies the validity function of the result produced by fuzzy clustering based on two aspects, which reflect the un-certainty of classification during fuzzy partition and spatial location features of spatial data, and proposes a new validity function of fuzzy clustering for spatial data. The experimental result indicates that the new validity function can accurately measure the validity of the results of fuzzy clustering. Especially, for the result of fuzzy clustering of spatial data, it is robust and its classification result is better when compared to other indices.
基金supported by the Sichuan Tourism Youth Expert Training Program in Sichuan Provincial Tourism Development Committee (Grant No. SCTYETP2017L05) the Young Scholars Training Program in Chengdu University of Technology (Grant No. KYGG201424)
文摘The mid-southern section of the Hengduan Mountains is a typical region of mountainous landscape in western China and is the core region of "Shangri-La", a world-famous ecotourism destination. The landscape classification system is an important scientific basis for landscape protection and tourism development in this region. By combining geology and geography and referring to the concepts of "system tract" and "tectonic system" in geology, this paper comes up with grading standards for the geoscience landscape system of this region. Based on the regional stratigraphic structure, tectonic fault marks and geomorphological differentiation, this paper comes up with 2 Grade Ⅰ geoscience landscape system tracts, 8 Grade Ⅱ geoscience landscape systems, 21 Grade Ⅲ geoscience landscape areas, and 165 representative Grade Ⅳ geoscience landscape attractions. According to the main classification methods for the geological heritage and tourism landscapes, the geoscience landscapes can be divided into 4 categories, 16 types and 19 subtypes. On this basis, 23 eco-tourism areas of the mid-southern section of the Hengduan Mountains can be delimited. The study provides a theoretical direction and method reference for the geoscience landscape division and tourism zonation, which has an importantsignificance on the mountain landscape protection and tourism development in the regions of complex geo-environments.
基金Funded by the National 863 Program of China (No.2002AA130406)the Key Project of China Geological Survey (No.200218310077).
文摘One of the core developments in geomathematics in now days is the use of digital data processing in mineral prospecting and assessment. The information discovery is based on multidisciplinary geoscientific data and an integrated management approach is crucial. The lack of a standard description hinders interoperations in database search and discovery. Metadata hierarchy aims to provide a standard view of the geoscientific data, and facilitate data description and discovery. In the research of integrated geoscientific database, the metadata hierarchy used a standardized description for each collection in the content structure and realized in semantic structure. It recorded both dataset identification and inner structures and relationships of objects, thus differed from many other applications. There were four tiers in the content structure and three levels in the semantic structure. With its help, database users could determine how applicable a dataset is to a project, and improve their queries to the database. Effectiveness of data accessing is significantly enhanced through the rich, consistent metadata.
文摘Similarity relation is one of the spatial relations in the community of geographic information science and cartography.It is widely used in the retrieval of spatial databases, the recognition of spatial objects from images, and the description of spatial features on maps.However, little achievements have been made for it by far.In this paper, spatial similarity relation was put forward with the introduction of automated map generalization in the construction of multi-scale map databases;then the definition of spatial similarity relations was presented based on set theory, the concept of spatial similarity degree was given, and the characteristics of spatial similarity were discussed in detail, in-cluding reflexivity, symmetry, non-transitivity, self-similarity in multi-scale spaces, and scale-dependence.Finally a classification system for spatial similarity relations in multi-scale map spaces was addressed.This research may be useful to automated map generalization, spatial similarity retrieval and spatial reasoning.
基金supported by the National Basic Research Program of China (Grant Nos. 2009CB421401 and 2006CB400503)
文摘Trends in six indices of precipitation in China for seasons during 1961-2007 were analyzed based on daily observations at 587 stations. The trends were estimated by using Sen's method with Mann-Kendall's test for quantifying the significance. The geographical patterns of trends in the seasonal indices of extremes were similar to those of total precipitation. For winter, both total and extreme precipitation increased over nearly all of China, except for a small part of northern China. Increasing trends in extreme precipitation also occurred at many stations in southwestern China for spring and the midlower reaches of the Yangtze River and southern China for summer. For autumn, precipitation decreased in eastern China, with an increasing length of maximum dry spell, implying a drying tendency for the post-rainy season. Wetting trends have prevailed in most of western China for all seasons. The well-known 'flood in the south and drought in the north' trend exists in eastern China for summer, while a nearly opposite trend pattern exist for spring.