Spatio-temporal variation of landscape heterogeneity under influence of human activities in Xiamen City of China in recent decade   总被引：1，自引：0，他引：1  

HUANG Yixiong  YIN Xiuqin  YE Gongfu  LIN Jiemin  HUANG Ru  WANG Na  WANG Liang  SUN Yue 《中国地理科学(英文版)》2013,23(2):227-236

Xiamen is an economically competitive and highly urbanized city along the coastal area of Fujian Province, China. The research on spatio-temporal variation of landscape heterogeneity under the influence of human activities is of great importance to the further study on the relationship of landscape pattern and ecological process. It is also crucial to the discovery of spatial variation and intensity distribution of human activities. The research analyzed the intensity of human impacts and the spatial variation features and dynamics of landscape patterns by introducing statistical theories and approaches. We analyzed spatio-temporal variation of landscape heterogeneity using the geostatistical techniques, such as semivariogram and Kriging interpolation.Results show that there is a higher correlation between landscape heterogeneity indexes and human impact index. Both the indexes show a moderate spatial autocorrelation as well as an obvious characteristic of anisotropy. From 1998 to 2008, the spatial differentiation of the changes in the intensity of human activities and the changes in landscape heterogeneity shows that the landscape patterns in Xiamen are closely related with the urban land utilization methods, the condition of traffic and geographical location and the physical geographical condition such as the terrain and the ecological environment. The process of urbanization has a significant impact on the urban landscape pattern.  相似文献   

A review on the South China Sea western boundary current   总被引：7，自引：2，他引：5  

FANG Guohong  WANG Gang  FANG Yue  FANG Wendong 《海洋学报(英文版)》2012,31(5):1-10

The advances in understanding the South China Sea (SCS) western boundary current (SCSwbc) have been reviewed since the works of Dale (1956) and Wyrtki (1961) in the middle of the 20th century. The features of the pattern of SCSwbc and the oceanic phenomena associated with it are focused on. The current is driven mainly by monsoon over the SCS and partially by winds over the tropical Pacific governed by the island rule. The SCSwbc exhibits strong seasonal variation in its direction and patterns. In winter, the current is strong and flows southwestward along the South China shelf and slope from the east of Dongsha Islands to the northern central Vietnamese coast, then turns to the south along the central and southern Vietnamese coast, and finally partially exits the SCS through the Karimata Strait. In summer and early fall, the SCSwbc can be divided into three segments based on their characteristics. The southern segment is stable, flowing northward from the Karimata Strait up to about 11 N, where it separates from the coast forming an eastward offshore current. The separation of the current from Vietnamese coast induces some striking features, such as upwelling and cold sea-surface temperature. The middle segment off the central Vietnamese coast may have a bimodal behavior: northward coastal current and meandering current in early summer (June-July), and cyclonic gyre in later summer and early fall (August-September). The northern segment is featured by the summer SCS Warm Current on the South China shelf and a southwestward subsurface current along the continental slope.  相似文献   

Three-Dimensional Density Distribution and Seismic Activity along the Guxiang–Tongmai Segment of the Jiali Fault, Tibet     

FAN Pengxiao  YU Changqing  WANG Ruixue  ZENG Xiangzhi  QU Chen  ZHANG Yue 《《地质学报》英文版》2024,98(2):454-467

The Guxiang–Tongmai segment of the Jiali fault is situated northeast of the Namche Barwa Syntaxis in northeastern Tibet. It is one of the most active strike-slip faults near the syntaxis and plays a pivotal role in the examination of seismic activity within the eastern Himalayan Syntaxis. New study in the research region has yielded a 1:200000 gravity dataset covering an area 1500 km2. Using wavelet transform multiscale decomposition, scratch analysis techniques, and 3D gravity inversion methods, gravity anomalies, fault distributions, and density structures were determined across various scales. Through the integration of our new gravity data with other geophysical and geological information, our findings demonstrate substantial variations in the overall crustal density within the region, with the fault distribution closely linked to these density fluctuations. Disparities in stratigraphic density are important causes of variations in the capacity of geological formations to endure regional tectonic stress. Earthquakes are predominantly concentrated within the density transition zone and are primarily situated in regions of elevated density. The hanging wall stress within the Guxiang–Tongmai segment of the Jiali fault exhibits a notable concentration, marked by pronounced anisotropy, and is positioned within the density differential zone, which is prone to earthquakes.  相似文献   

Geobag stepped spillway for check dams: A pilot study     

Shu Yu  Fan Yue  Qiang Zhang  Zuyu Chen  Penghai Yin  Jianwei Hao  Laizhang Zhang  Ludong Hao 《国际泥沙研究》2023,38(1):115-127

Check dams are widely used worldwide for the soil and water conservation. Many of them have no spillways, resulting in frequent dam breach failures during heavy rainfall events. This paper proposes a new geobag stepped spillway for small check dams. The structure of the spillway primarily consists of a stepped chute created from geobags filled with local soil compacted and consolidated with a small amount of cement. The developed composite geosynthetic material exhibits water erosion resistance,...  相似文献   

Spatio-temporal Evolution of Urban Expansion Based on a Novel Adjusted Index and GEE: A Case Study of Central Plains Urban Agglomeration,China     

SU Yanlin  LU Chunyan  SU Yue  WANG Zili  HUANG Yufei  YANG Nuocheng 《中国地理科学(英文版)》2023,(4):736-750

It is crucial to investigate the urban agglomerations spatio-temporal evolution patterns and driving factors for analyzing the urban spatial structure-functional division and promoting the coordinated development of urban agglomerations. In this study, a novel vegetation-building-nighttime light-adjusted index(VBNAI) was established for rapid and effective mapping of urban construction land(UCL) in Central Plains Urban Agglomeration(CPUA), China during 2000–2020 based on Google Earth Engine(GEE)...  相似文献   

Source rupture model of the 2018 Mw6.7 Iburi,Hokkaido earthquake from joint inversion of strong motion and InSAR observations          下载免费PDF全文

Chunmei Ren  Han Yue  Teng Wang  Zeyan Zhao 《地震科学（英文版）》2021,34(1):88-101

The 2018 Mw6.7 Iburi earthquake shocked the eastern Iburi region to the west of the Hidaka Collision Zone in Hokkaido,which is a destructive inland earthquake.We resolved the kinematic rupture process of the event by combining strong motions(SM)and synthetic aperture radar(SAR)images in a joint inversion.The results reveal that the duration of the whole rupture is about 17s,yielding a total seismic moment of 1.4×1019 N·m(Mw=6.7).The main slip area is located at a depth of approximately 24 km with a peak slip of～0.8m above the hypocenter.The comparison with the regional velocity model shows the earthquake was initiated in the upper mantle,while the majority of slips are located in the lower crust,which is an"aseismic"domain in the typical sandwich model.The location of the major slip area is consistent with a high-conductivity volume.We proposed a mechanism of low frictional property(＜0.3)produced by high pore pressure to explain the abnormal high dip angle and centroid depth located in the ductile lower-crust.Aftershocks are distributed in areas where the Coulomb frictional stress increases due to co-seismic displacement with a mechanism conjugating to the mainshock.  相似文献   

福建兴化湾海域沉积物中的甲藻孢囊记录   总被引：1，自引：0，他引：1  

ZHU Yue  孙爱梅  LI Chao  蓝东兆  ZHANG Jin-peng 《台湾海峡》2008,27(3)

通过对福建兴化湾海域表层和柱状沉积物中甲藻孢囊的分析,共鉴定出10 属29种(含不定种)甲藻孢囊.其中发现有毒种类7种:微小亚历山大藻(Alexandrium minutum)、多环旋沟藻(Cochlodinium polykrikoides)、多边舌甲藻(Lingulodinium polyedrum)、具刺膝沟藻(Gonyaulax spinifera)、链状裸甲藻(Gymnodinium catenatum)、网状原角管藻(Protoceratium reticulatum)和锥藻斯氏藻(Scrippsiella trochoidea).表层沉积物中总甲藻孢囊丰度值在13～88粒/g之间,柱状沉积物中总甲藻孢囊的丰度在40～105粒/g以内.通过与周边其他海域甲藻孢囊属种组成及丰度值对比,表明兴化湾甲藻孢囊的丰度值较高,并且7种有毒种类的存在对该海域发生有毒有害赤潮构成潜在威胁,相关政府部门及周围居民应加以重视和防范.  相似文献   

Geographical features and development models of estuarine cities     

CHEN Mingxing  XIAN Yue  HUANG Yaohuan  SUN Zhigang  WU Chengbin 《地理学报(英文版)》2024,(1):25-40

Cities are the key areas for human beings to achieve sustainable development goals in the future. Estuarine cities are a special type of coastal city in urgent need of a clear definition. This paper proposed that estuarine cities are cities developed on the coast where rivers and oceans meet and defined four connotations, including the intersection of rivers and marine water systems, the coordinated development of land and oceans, the location advantages of connecting rivers and seas, and the im...  相似文献   

The Changhsingian small foraminifers from the Gyanyima section in southern Tibet, China     

WANG Yue  Katsumi UENO  CAO Chang-qun  ZHANG Yi-chun 《地球学报》2009,30(Z1):87-87

The Gyanyima section is located in the Himala-yan Tethys Zone, just south of the Indus-Tsangbo su-ture. The Permian part of the section is made up of grayish to reddish white reefal limestone that yields rich warm-water faunas of Changhsingian age. We recently found highly diversified smaller foraminifers dominated by Colaniella parva in association with the genera Pachyphloia, Frondina, Nodosaria, Robuloides, Geinitzina, Tetrataxis, Tuberitina, Abadehella, Cli-macammina, Dagmarita, Postendothyra, Neoendo-thyra, Globivalvulina, Paraglobivalvulina, Agatham-mina, Multidiscus, and Kamurana. In comparison, fusulinoideans are a minor element of the fauna and include Nankinella, Staffella, Reichelina pulchra, and Codonofusiella?. In addition to these fusulinoideans, a new boultoniid genus is found in the upper part of the section. This form shares some similarities with Codonofusiella and Parananlingella in its un-coiling or loose-coiling tendency in the last volution, but it is distinct from these two boultoniid genera in having a rapidly expanding but fully coiled last half volution.  相似文献   

Comparative Analysis of Sequence Characteristics among Different Superimposed Stages of the Chelif Basin,Algeria   总被引：1，自引：0，他引：1  

ZHANG Yuanfu  JIANG Zaixing  WANG Yue  BAO Dandan 《《地质学报》英文版》2009,83(6):1041-1051

Abstract: Superimposed basins were investigated with respect to tectonic evolution, sediment deposition and petroleum characteristics within a single superposition stage generally. The comparative study was seldom seen. Sequence characteristics were compared for two different superimposed stages – an expanding rifting stage and a depression-foreland transition stage – in the Chelif Basin during the Miocene in this paper. A model and mechanism for sequence evolution of superimposed basins in different dynamic situations are discussed with respect to sequence similarities and differences. The compared characters include sequence thickness, sequence boundaries and system tracts, as well as sediment deposition within sequences and sequence development patterns. Finally, some typical features of sequence development concomitant with changes of superimposed stages in the Chelif Basin are discussed.  相似文献