Sediment settling in the Latian Dam in Iran     

Farhang BEHRANGI  Mohammad Ali BANIHASHEMI  Shayesteh MAHANI  Mohammad Reza RAHMANIAN 《国际泥沙研究》2014,29(2):208-217

Among the difficulties that influence future dam operations,reservoir sedimentation is the most problematic for engineers.This study predicted the amount and pattern of sedimentation for use in estimation of the useful lifespan of reservoirs and identification of optimal locations for outlets and intakes at the initial stages of dam design.Hydrographic surveys of different dams can provide better insight into this phenomenon.Latian Dam in Iran has conducted hydrographic surveys during 7 time periods.The amount and process of sedimentation in this reservoir were determined,and predictions of distribution of sediments were validated by well-known,common methods.The formation of a delta in the reservoir was investigated for different time periods after operation.Future problems due to the impacts of sedimentation on dam operation and the useful lifespan of the reservoir were predicted.In addition,the study results may be used for developing empirical methods to predict sedimentation patterns in other reservoirs.  相似文献   

深水峡谷体系控制因素分析——以南海北部琼东南盆地中央峡谷体系为例   总被引：1，自引：0，他引：1  

苏明  ;张成  ;解习农  ;王振峰  ;姜涛  ;何云龙  ;张翠梅 《中国科学:地球科学》2014,(8):1807-1820

利用2D/3D地震数据及钻井资料,详细解剖了晚中新世以来构造-沉积背景对琼东南盆地大型轴向峡谷体系形成和演化的控制.晚中新世以来的大规模海平面下降导致了陆坡区的沉积物易发生失稳,从而为中央峡谷体系沉积充填提供了物源.峡谷内部的2套沉积物:浊流沉积体和块体搬运复合体,分别来自西北部物源和北部物源,不同部位沉积物供给能力的差异,导致峡谷内部表现出不同的充填结构和样式.11.6 Ma时期构造变革事件为峡谷的形成提供了构造背景,盆地东部形成的轴向"限制型"小型盆地可视为中央峡谷体系的雏形.5.7 Ma时期红河断裂带右旋走滑的活动,将增强莺-琼盆地交界处沉积物的水动力条件,并向浊流发生演变,形成深水浊积水道.南部隆起的存在对峡谷内部充填沉积物起到了"遮挡"的作用.更新世以来的气候因素所引起的强烈沉积物供给和盆地东部特殊的地貌特征,引起了中央峡谷体系的"回春",大量垮塌沉积体的发育将进一步加剧峡谷的"负地形"特征.研究表明,琼东南盆地中央峡谷体系自西向东不同区段的主控因素存在差异:西北部物源的供给和红河断裂带在5.7 Ma时期的构造活动控制了头部区域浊积水道的形成和发育;西北部物源、北部陆坡的沉积物供给、构造地貌特征等,控制了峡谷自西向东的运动,并影响了峡谷内部的充填结构;盆地东部11.6 Ma时期的构造变革和长昌凹陷有限的沉积物供给能力是盆地东段中央峡谷体系的主控因素.  相似文献   

中巴喀喇昆仑公路(巴基斯坦境内)河床沉积物与泥石流堆积物的关系     

胡进  ;朱颖彦  ;杨志全  ;廖丽萍 《中国地质灾害与防治学报》2014,25(3):1-8

统计分析中巴公路沿线红其拉甫河(Khunjerab River)、洪扎河(Huza River)、吉尔吉特河(Gilgit River)、印度河(India River)共计45个河床沉积物样本,对比分析了样本的平均值、中值、分选系数、偏态和峰度等粒度参数,初步探讨了公路沿线河床沉积物粒度分布与区域内泥石流沉积物的关系,结果表明河流沉积物主要来源于泥石流补给,因而具有了类似于泥石流沉积物的分布特征。  相似文献   

粤西-琼东北近海沉积物的运移和沉积     

许冬  初凤友  李家彪  杨海丽  陈亮 《吉林大学学报(地球科学版)》2014,44(3):905

为了深入认识珠江现代入海物质在粤西陆架随海流迁移扩散的路径和沉积中心,利用Gao-Collins方法分析了粤西-琼东北近海1 515个站位的粒径趋势,并用²¹⁰Pb法测定了8支柱样的现代沉积速率。结果表明,在粤西沿岸流和南海暖流这两个相向海流的共同作用下,珠江口外珠江来源的泥质沉积物的主体被限制在-50 m等深线以浅的内陆架。现代珠江入海物质能维持粤西陆架泥质沉积区0.1 cm/a左右的现代沉积速率。在川山群岛至海陵岛一带和琼州海峡东侧泥质区,分别受岛屿阻挡和逆时针中尺度涡旋的影响,形成了现代沉积中心。在沉积物不同粒级的来源和搬运方式存在差异的地方,粒径趋势分析结果可能主要反映的是粗颗粒沉积物的运移趋势,而非细颗粒沉积物的运移方向。  相似文献   

广西防城港海域沉积物特征及输运趋势     

张亮  梁开  甘华阳  崔振昂 《热带地理》2014,34(5):690-695

通过对2010―2011年在广西防城港海域表层沉积物所取样品进行粒度实验,并利用二维沉积物粒径趋势分析模型进行了粒径输运趋势分析。结果表明,研究区海域底质沉积物类型主要为砂、粉砂质砂、砾石质砂、砂-粉砂-黏土、黏土质粉砂和砂质粉砂等6种。粒度参数在空间分布上,沿岸和西部海域中值粒径较粗,分选中等或较好,偏态呈正偏或极正偏,在海湾口处呈负偏或极负偏;东南部海域粒径较细,分选系数差,偏态呈负偏或近对称。根据沉积物输运趋势方向不同,将研究海域分为3个区：沿岸海域主要离岸输送,方向由北向南;东南部海域的沉积物输运趋势向中间汇聚,形成一个沉积中心;西南部海域,沉积物输运方向偏北。  相似文献   

南黄海中部海底沉积物声阻抗特性     

阚光明  苏远峰  刘保华  李官保  孟祥梅 《吉林大学学报(地球科学版)》2014,44(1):386

基于在南黄海中部海域获得的大量海底沉积物样品及其测试数据,分析讨论了该区域海底浅表层沉积物声阻抗特性及其与沉积物物理力学性质参数的相关关系。研究表明:研究区浅表层沉积物声阻抗呈现出分区域分布的特征,可分为西南部声阻抗高值区、东北部声阻抗低值区以及北西-东南向声阻抗梯度带3个区域。通过回归分析,建立了声阻抗与沉积物物理力学参数的经验回归方程。结果表明:声阻抗与密度、含水率、孔隙比、孔隙度、液限、塑限、塑性指数、压缩系数等参数的相关性较好,判定系数R²一般大于0.8,而与砂粒含量、黏粒含量、中值粒径、抗剪强度等参数的相关性相对较差,判定系数R²一般小于0.7。将声阻抗与物理力学性质的相关性和声速与物理力学性质的相关性进行了对比,结果表明,声阻抗与上述参数的判定系数R²均大于声速与上述参数的判定系数,从而表明声阻抗是一个能够更好地反映声学特性与物理力学性质关系的沉积物声学特性参数。  相似文献   

临夏盆地13～4.4 Ma湖相沉积物颜色记录的气候变化探讨   总被引：18，自引：0，他引：18  

宋春晖  白晋锋  赵彦德  金洪波  孟庆泉 《沉积学报》2005,23(3):507-513

利用高分辨率的代用资料来恢复古气候环境变化是当前过去全球变化研究的重要内容.通过对临夏盆地13～4.4 Ma时段稳定湖泊沉积物以10 cm间隔连续采得的2 060块样品进行颜色测定与分析,获得该时段湖相沉积物高分辨率颜色指标变化序列.通过沉积物颜色与成分分析,并与氯离子、CaCO3、风成石英砂含量和孢粉组合以及北太平洋ODP885/886孔的风成粉沙通量变化曲线对比,认为稳定湖相沉积物颜色指标是研究古气候变化的辅助性代用指标,并揭示了该地区在8 Ma和6.2 Ma左右存在两次重大的气候变干转型事件.  相似文献   

贵州主要城市地表松散沉积物中微量元素与土壤环境   总被引：2，自引：0，他引：2  

何邵麟 陈敏刘应忠  任明强汪玉琼袁义生  杨清群 《贵州地质》2005,22(3):147-155

通过贵阳等九个城市地表土壤和水系沉积物中的微量元素地球化学分析表明,城市环境不同程度地遭受有微量元素污染.在自然作用和人为作用过程中,微量元素造成城市的大气污染、水土污染、元素异常、环境灾变等环境问题,笔者认为,贵州城市地表土壤和沉积物中的生命有害元素污染,可能对长江和珠江流域造成不良影响,应尽快开展多目标生态环境地球化学调查,科学准确的划分地表环境的安全、隐患及污染区,并对已遭受微量元素污染的地区制定出有效的修复方案和治理措施.  相似文献   

Late Paleozoic Fluid Systems and Their Ore-forming Effects in the Yuebei Basin, Northern Guangdong, China   总被引：1，自引：0，他引：1  

DENG Jun  YANG Liqiang  SUN Zhongshi  WANG Jianping  WANG Qingfei  CHENG Xueming  ZHOU Yinghua State Key Laboratory of Geological Processes  Mineral Resources  China University of Geosciences  Beijing  Key Laboratory of Lithosphere Tectonics  Lithoprobing Technology of the Ministry of Education  China University of Geosciences  Beijing School of Earth Sciences  Jilin University  Chuangchun  Jilin 《《地质学报》英文版》2005,79(5):673-687

Based on detailed and systematic researches of the geology of ore deposits, fluid inclusions and isotope geochemistry etc., and regarding the Late Paleozoic fluid system of the Yuebei Basin as an integrated object in this paper, we have revealed the temporo-spatial evolution law of the basin＇s fluid system and discussed its ore-forming effects by simulating and analyzing the distribution of ore-forming elements, the fluid thermodynamics and dynamics of evolution processes of this basin. The results show that Late Paleozoic ore-forming fluid systems of the Yuebei Basin include four basic types as follows. （1） The sea floor volcanic-exhalation system developed during the rapid basin slip-extension stage in the Mid-Late Devonian, which affected the Dabaoshan region. It thus formed the Dabaoshan-type Cu-Pb-Zn-Fe sea floor volcanic-exhalation sedimentary deposits. （2） The compaction fluid system developed during the stable spreading and thermal subsidence-compression stage of the basin in the Mid-Late Devonian. The range of its effects extended all over the whole basin. It resulted in filling-metasomatic deposits, such as the Hongyan-type pyrite deposits and pyrite sheet within the Fankou-type Cu-Pb-Zn-S deposits. （3） The hot water circulation system of sea floor developed during the stage of basin uplifting and micro-aulacogen from the late Late Carboniferous to Middle Carboniferous. The range of its effects covered the Fankou region. It thus formed MVT deposits, such as the main orebody of the Fankou-type Pb-Zn-S deposits. （4） The gravity fluid system developed during the stage of fold uplifting and the basin closed from Middle Triassic to Jurassic, forming groundwater hydrothermal deposits, e.g. the veinlet Pb-Zn-calcite orebodies of the Fankou-type Pb-Zn- S deposits. Migration and concentration of the ore-forming fluids were constrained by the state of temporo-spatial distribution of its fluid potential. Growth faults not only converged the fluids and drove them to move upwards, but also the fluids often crossed the faults to the edges of the basin at the bottom of these faults and the lithologic interfaces, and even migrated to the basin＇s edges from top to bottom along the faults, which may be one of the basic reasons for the stratabound deposits to cluster mainly along the contemporaneous faults on the inner border of the basin. The superposed mineralization resulting from the multi-stage activity of contemporaneous faults and ore-forming fluid systems in the basin may be one of the key factors for forming superlarge ore deposits.  相似文献   

Extreme Enrichment of Tellurium in Deep-Sea Sediments   总被引：2，自引：0，他引：2  

LI Yanhe  WANG Yimin  SONG Hebin  and YUE Guoliang  Laboratory of Isotope Geology  Ministry of Land  Resources  Beijing  E-mail: lyh@mx.cei.gov.cn Institute of Mineral Resources  Chinese Academy of Geological Sciences  Beijing  National Geoanalysis Center  Beijing 《《地质学报》英文版》2005,79(4):547-551

Tellurium is a sort of scattered rare element on the earth. Its concentration is very low in earth＇s crust, only 1.0 ng/g. However, it has extremely high abundance in Co-rich crusts, marine polymetallic nodules, deep-sea sediments and aerolites. To find out the origin of tellurium enrichment in deep-sea sediments, we analyzed and compared tellurium concentrations and helium isotope compositions in the magnetic parts and those in the bulk parts of deep-sea sediments. The result indicates that the helium content, 3He/4He ratio and tellurium concentration are obviously higher in the magnetic parts than those in the bulk parts. The 3He abundance varies synchronously with the tellurium concentration. 3He and Te have a distinct positive correlation with each other. It is the first time that the paper brings forward that the extreme enrichment of tellurium in deep-sea sediments, like helium isotope anomalies, probably results from the input of interplanetary dust particles （IDPs）. Similarly, the extreme enrichment of tellurium in marine polymetallic nodules and Co-rich crusts is possibly related to IDPs.  相似文献