Cambrian- Ordovician Deep - Water Deposits in Southwest Jiangxi, China     

Ji LeiNanjing Institute of Geography  Limnology  Academia Sini  Nanjing Jiang Minxi 《《地质学报》英文版》1994,68(4):435-449

The Cambrian-Ordovician rocks in southwestern Jiangxi are mainly composed of deep-water deposits, in which 5 facies have been recognized: sandstone facies, sandstone-mudstone facies, siltstone-mudstone facies, mudstone (slate)facies, and chert facies. They are of turbidity current origin and are related to pelagic and hemipelagic deposits. In the light of facies distribution, the Cambrian-Ordovician deposits can be classified into 3 facies associations formed in middle fan, outer fan and deep-sea plain environments respectively. The 3 different orders of vertical cycles in the stratigraphic sequence are considered to be controlled by factors such as sea-level fluctuation, basin subsidence and submarine fan progradation. The tectonic setting of the sedimentary basin is interpreted as passive continental margin based on the chemical composition analysis of the sandstone.  相似文献   

Rural settlements,mission settlements and rehabilitation in Transkei   总被引：1，自引：0，他引：1  

Prof. of Geography Colin A. Lewis Ph. D.  A. Z. Mrara B. A. 《GeoJournal》1986,12(4):375-386

During the 19th century the predominant form of rural settlement in Transkei was that of dispersed homesteads. The form of the homesteads tended to differ from tribe to tribe, while the homesteads of various tribal groups were separated from each other by uninhabitated areas, or buffer zones. During the 19th century mission settlements were introduced to Transkei, some of which developed into towns.In the 20th century, mainly as a result of government action, homesteads have been nucleated into rural settlements and villages and much of the land has been fenced. A few peri-urban and industrial villages also exist in Transkei. Over 95% of the population of Transkei in 1980 were still rural dwellers.  相似文献   

Geographical characteristics of China’s wetlands derived from remotely sensed data   总被引：6，自引：0，他引：6  

NIU ZhenGuo  GONG Peng  CHENG Xiao  GUO JianHong  WANG Lin  HUANG HuaBing  SHEN ShaoQing  WU YunZhao  WANG XiaoFeng  WANG XianWei  YING Qing  LIANG Lu  ZHANG LiNa  WANG Lei  YAO Qian  YANG ZhenZhong  GUO ZiQi & DAI YongJiu State Key Laboratory of Remote Sensing Science  Jointly Sponsored by Institute of Remote Sensing Applications  Chinese Academy of Sciences    Beijing Normal University  Beijing  China  School of Geography  Beijing Normal University  Beijing 《中国科学D辑(英文版)》2009,52(6):723-738

In this paper, we report the first wetland mapping of the entire China using Landsat enhanced thematic mapper plus (ETM+) data. These data were obtained from the Global Land Cover Facility at the University of Maryland spanning from 1999 to 2002. A total of 597 scenes of Landsat images were georeferenced and mosaiced. Manual image interpretation of satellite images was aided with elevation data, soil data, land cover/land use data and Google Earth. The minimum mapping unit is 10 pixel × 10 pixel, equivalent...  相似文献   

[专稿]太湖梅梁湾2007年蓝藻水华形成及取水口污水团成因分析与应急措施建议   总被引：37，自引：15，他引：22  

中国科学院南京地理与湖泊研究所 《湖泊科学》2007,19(4):357-358

2007年4月25日起太湖梅梁湾暴发了大规模藻类水华暴发时间比过去提前近1个月.根据中国科学院太湖湖泊生态系统国家野外科学观测研究站的监测,5月2日梅梁湾所有测点藻类叶绿素a含量全部超过40μg/L,其中三山-鼋头渚水域达179μg/L;5月27日的卫星影像图片显示,太湖北部的竺山湾和贡湖湾以及整个西部湖区均发生了大面积的蓝藻水华;随后5月28日晚,无锡贡湖湾口南泉水厂发生污水团进入水厂取水口恶化水源水质事件,给人民的日常生活带来了短暂的影响.  相似文献   

Phases of Environmental Evolution Indicated by Primary Chemical Elements and Paleontological Records in the Upper Pleistocene-Holocene Series for the Salawusu River Valley, China   总被引：4，自引：0，他引：4  

LI Baosheng WEN Xiaohao QIU Shifan David Dian ZHANG DU Shuhuan CHEN Deniu OU Xianjiao NIU Dongfeng 《《地质学报》英文版》2007,81(4):555-565

Studies of lithology, sedimentary facies and the distribution regularity of SiO2 and Al2O3 contents and Al2O3/SiO2 ratio allow us to divide the Upper Pleistocene-Holocene Series represented by the MUanggouwan section in China＇s Salawnsu River valley into six segments： MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6. The boundary ages for MGS1 （the Dishaogouwan and Dagouwan Formations）, MGS2 （the upper Chengchuan Formation）, MGS3 （the middle Chengchuan Formation）, MGS4 （the lower Chengchuan Formation）, MGS5 （most strata of the Salawusu Formation） and MGS6 （the bottom of the Salawusu Formation and the top of the Lishi Formation） correspond to those of MIS1, MIS2, MIS3, MIS4, MISS and MIS6, respectively, from deep sea sediments or continental glaciers. MGS5 can be subdivided into five subsegments （MGS5a, MGS5b, MGS5c, MGS5d and MGS5e） and the boundary ages of these subsegments correspond to those of MISSa, MISSb, MIS5c, MIS5d and MIS5e, respectively. Based on the paleoenvironment and paleoecology indicated by the primary chemical elements, fossil vertebrates, mollusks and pollen grains, we hypothesize that MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6 and the subsegments of MGS5 match the corresponding stages for oxygen isotopes in the deep sea sediments and continental glaciers, and the substages of MIS5 in terms of climatic characters, further explaining the phenomena that determined the formation of the late Quaternary strata and the paleontology of the Salawusu River valley. These phenomena relate to fluctuations in the global climate （and particularly in the East Asian monsoon） during the glacial and interglacial periods.  相似文献   

Changes of Atmospheric Circulation since the LastInterstadial as Indicated by the Lake-statusRecord in China   总被引：1，自引：0，他引：1  

XUE Bin  YU GeNanjing Institute of Geography  Limnology  Chinese Academy of Sciences  Nanjing 《《地质学报》英文版》2000,74(4):836-845

The effective precipitation and the frame of atmospheric circulation in the past three key periods, i.e. 30 ka BP, 18 ka BP and 6 ka BP, have been analyzed on the basis of the palaeolake status record produced by the Chinese Lake Status Data Base. The results show that the west-central part of China was characterized by high lake-levels at 30 ka BP, resulting from strengthened southwest monsoons; whereas the high lake stand, occurring in the west-central part of China at 18 ka BP, was caused by the southward shift and the strengthening of westerlies although the high-stand distribution was reduced. Meanwhile, the east-central part of China was under the control of strong winter monsoons at 18 ka BP. The high lake-levels, which occurred in the east-central part of China at 6 ka BP, are related to the enhanced East-Asian summer monsoons; while the lowering of the lake-level in the west-central part of China at 6 ka BP was due to the northward shift and corresponding shrink of the westerlies.A comparison b  相似文献   

Runoff Variation Law and Its Response to Climate Change in the Headstream Area of the Keriya River Basin,Xinjiang     

凌红波  张青青  史薇  徐海量 《中国地质大学学报(英文版)》2011,(6)

Based on the runoff and meteorological data of Langan(兰干) Hydrological Station from 1957 to 2009 in Keriya(克里雅) River,the periodicities,abrupt changes,and trends of climate factors and runoff were investigated by wavelet analysis and nonparametric test;then,the future change of the annual runoff was predicted by a periodic trend superposition model.In succession,the influencing volumes of climate change on the annual runoff were separated from the observation values of the an-nual runoff in Keriya River.The...  相似文献   

An Improved Method Based on Shallow Ice Approximation to Calculate Ice Thickness along Flow-Line and Volume of Mountain Glaciers     

李慧林  李忠勤  张明军  李汶峰 《中国地质大学学报(英文版)》2011,(4)

To evaluate the water storage and project the future evolution of glaciers, the ice-thickness of glaciers is an essential input. However, direct measurements of ice thickness are labo-rious, not feasible everywhere, and necessarily restricted to a small number of glaciers. In this article, we develop a simple method to estimate the ice-thickness along flow-line of mountain glaciers. Different from the traditional method based on shallow ice approximation (SIA), which gives a relationship be-tween ice thickn...  相似文献   

基于改进的地表温度-植被覆盖特征空间估算地表蒸散   总被引：1，自引：0，他引：1  

孙亮  孙睿  李小文  陈怀亮  张雪芬 《资源与生态学报(英文版)》2011,(3):225-231

地表温度-植被指数特征空间被广泛应用与地表蒸散估算和土壤湿度监测,而利用散点图直接拟合干边会造成很大的不确定性。本研究采用改进的地表温度-植被覆盖特征空间进行地表通量的计算。该方法是基于能量平衡公式进行干边定位,从而减少干边确定过程中的不确定性。我们选取的17天的MODIS数据以及相应气象数据进行地表蒸散计算,并采用郑州的LAS观测站验证显热通量计算值,估算结果均方根误差（RMSE）、偏差（Bias）和相关系数平方（R^2）分别为44.06Wm^-2、36.99Wm^-2和0.71。总体来讲,通过能量平衡公式确定的理论干边相比通过散点图拟合的实测干边更合理。  相似文献   

Driving Mechanism of Cultivated Land Transition in Yantai Proper,Shandong Province,China     

QIN Weishan  ZHANG Yifeng  LI Guangdong 《中国地理科学(英文版)》2015,(3):337-349

Cultivated land transition and its driving mechanism are the hotspots among studies on land use change. In this study, we constructed a framework to study the driving mechanism of cultivated land transition from the quantitative perspective. Based on the vector data of land use in 1990, 2000 and 2009 of Yantai Proper, Shandong Province China, 11 explanatory variables were chosen from two aspects: the elevation, slope, cost distance to major water area and cost distance to minor water area, which presented physical factors; cost distance to district center, cost distance to town center, cost distance to city expansion center, cost distance to major roads, cost distance to city roads, cost distance to county roads and cost distance to rural roads, which presented the socio-economic factors. Combined with spatial analysis tools and Logistic regression analysis model, we construct Logistic regression analyses with four objectives that were urban construction land, rural residential land, orchard and other lands. The results show that, cost distance to district center, cost distance to town center, cost distance to city expansion center and cost distance to city roads are the significant explanatory variables for the transition of cultivated land into urban construction land. The main explained factors on the transition of cultivated land into rural residential land are slope, cost distance to town center, cost distance to county roads and cost distance to rural roads. Slope, cost distance to minor water area, cost distance to town center, cost distance to county roads and cost distance to rural roads are the significant explanatory variables for the transition of cultivated land into orchard land. Elevation, slope, cost distance to major water area and cost distance to minor water area are the main explanatory variables on the transition of cultivated land into other land uses.  相似文献