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1.
The aim of this work is to research the influence of natural climatic changes on the evolution of the coastal zone in modern times and the possible implication of human activities on the configuration of the present coastline. Comparison of data of two very far and different areas, the Po River delta, Adriatic Sea and the Huanghe River delta, Bohai Sea, reveals the planetary diffusion of climatic fluctuations and their effects on coastal evolution. Contribution No. 820 from the Marine Geology Institute, C. N. R., Italy. Contribution No.2207 from the Institute of Oceanology, Academia Sinica. Project supported by the National Natural Science Foundation of China.  相似文献   

2.
(季子修)(蒋自巽)IMPACTSOFSEALEVELRISEONCOASTALEROSIONINTHECHANGJIANGRIVERDELTAANDNORTHJIANGSUCOASTALPLAINO¥JiZixiu(NanjingInstitute...  相似文献   

3.
1SPLENDOROFHISTORICALCULTURE InChina,theChangjiang(Yangtze)RiverDelta①gen-erallymeansanadvancedproductivityandculture,whichaffectsdeeplynotonlythewholeChinabutal-sotheAsian-Pacificregion,evenEuropeandAfrica. 1.1CradlefortheCommunicationandPropagationofCivilization ThedevelopmentcourseoftheChangjiangRiverDelta'scultureisdevious,buttheNeolithicHemuduCultureexcavatedinYuyaoCityofZhejiangProvinceindicatestheadvancedpaddyriceculture;MajiabangCulture5000aB.P.andEastBridgeRuin…  相似文献   

4.
黄河三角洲是陆海交界地带,陆地海洋相互作用显著,泥沙所引起的岸滩演变、港口航道的淤积、水动力环境的改变等问题比较复杂。该文采用三维HEM-3D数值模型对黄河三角洲海域流场变化、盐度、悬浮泥沙浓度及海岸冲淤分布进行了潮流周期内的数值模拟分析。结果表明,黄河三角洲海域的悬浮泥沙浓度分布与潮流场变化和河口泥沙输入有密切的关系,在三角洲北部受五号桩外强潮流区的影响,近岸海底的泥沙发生明显的再悬浮,并在涨潮流向南输送,含沙量达1.5 g/L左右。在三角洲南部(现行河口区域和莱州湾区域),受现行河口入海泥沙扩散的影响显著。海域年冲淤分布,在北部废弃三角洲区域,由于海洋动力作用强烈,浅水冲刷,海底侵蚀显著,形成了明显呈沿岸展布的侵蚀中心,在侵蚀中心以外,侵蚀快速减弱。在现行河口区域,以淤积为主,在羽状流扩散的控制下,泥沙入海后向南输运,至莱州湾区域逐渐减弱。数值模拟的结果与卫星遥感解译的岸线变化基本一致,效果良好。  相似文献   

5.
In the river systems, the environmental change always undergoes a process from quantitative to qualitative change. The upper limit of the qualitative change is called threshold. When the process reaches or goes beyond the limit, the original event series will be replaced by the other event series. Investigations show that the evolution of the Huanghe River alluvial fan and delta has also under gone a process from quantitative to qualitative change. The geometric forms in each process are roughly the same. This threshold of the geometric forms not only provides us a quantitative index for plotting the periodicity of the alluvial fan and delta, but also is of importance for estimation of the trend of natural environmental change.It is shown that there are three periodic alluvial fans of the Huanghe River since the middle Holocene and four periodic delta since 1855 A.D., the thresholds of their geometric forms are from 0.93 to 0.94 and from 1.2 to 1.21 respectively.The changing trend in the past and the na  相似文献   

6.
The sedimentary history of a Huanghe(Yellow)River delta lobe can be divided into four stages.In the first stage,the crevasse splays and short-lived distributary channel deposits in the subaerial deltaand sheet silt in the subaqueous delta were well developed.In the second stage,further differentiationof sedimentary environments occurred in the subaerial delta lobe(distributary channel,natural levee,flood plain,central lower delta plain and lateral lower delta plain)and the subaqueous delta lobe(prodelta,delta front and delta lateral).In the third stage,crevasse splay and short-lived distributarychannel deposits mostly occurred in the lower or lower-middle part of the subaerial delta lobe,andsheet silt accumulated off the river mouth.In the fourth stage,the abandoned lobe was reworked.The common vertical sequence of the modern Huanghe River delta showed alternating clayey silt andsilt layers.A complete sequence from prodelta to upper delta plain was commonly composed of twoor more delta lobes.  相似文献   

7.
通过在该地区进行1:5万区域地质调查工作及沉积相研究工作,系统地建立了该地区石炭纪地层的沉积序列。在沉积相研究基础上,肯定该区石炭系存在着三角洲沉积体系,并通过对比,说明为浅水三角洲沉积。  相似文献   

8.
黄河三角洲是中国唯一一块保存最完整、最典型、最年轻的湿地生态系统,由于其地理位置优越、自然资源丰富等特点,在国际上备受关注。该文在已有资料分析、现场地质调查、遥感数据分析的基础上,构建了黄河三角洲湿地资源地质环境评价指标体系,采用定量与定性相结合的方法,将黄河三角洲湿地地质环境质量分为5个等级(优、良、一般、较差和差),研究结果表明,该地区19个县(市、区)中湿地地质环境资源质量为良的有8个,质量一般的为11个,总体处于健康-疾病的临界状态。并基于以上研究成果,针对性地提出了黄河三角洲湿地资源保护对策。  相似文献   

9.
随着国家对黄河三角洲高效生态经济区发展规划的批复,如何加强黄河入海流路管理及其范围内土地开发,既要符合国家对河口治理的综合规划和土地规划,又能促进黄河三角洲高效生态经济快速发展,已成为突出问题。文章对黄河入海河口基本情况及如何管理和对其范围内土地进行合理利用开发提出了建议和意见。  相似文献   

10.
黄河三角洲国家级地质遗迹保护区总面积15.3万hm2,与国内外其他河流三角洲沉积相比,黄河三角洲的沉积环境和沉积模式有其独特之处,主要是黄河三角洲平原在发展演化过程中形成的各种河流沉积地貌景观、微地貌景观和河口地貌景观。研究和保护这些地质地貌遗迹,对了解黄河三角洲的演化过程、发展趋势以及提出合理的保护措施有重要意义。  相似文献   

11.
The Huanghe (Yellow) River, with annual sediment discharge about 11 ×108tons, contributes about 17% of the fluvial sediment discharge of world's 21 major rivers to the ocean because its middle reaches flow across the great Loess Plateau of China. Sediment discharge of the Huanghe River has a widespread and profound effect on sedimentation of the sea. The remarkable shift of its outlet in 1128-1855 A.D. to the South Yellow Sea formed a large subaqueous delta and provided the substrate for an extensive submarine ridge field.The shift of its outlet in the modern delta every 10 years is the main reason why with an extremely heavy sediment input and a micro- tidal environment, the Huanghe River has not succeeded in building a birdfoot delta like the Mississippi. The Huanghe River has consistently brought heavy sediment input to sea at least since 0.7 myr.B.P. Paleochannels, paleosols, cheniers and fossils on the sea bottom indicate that the Yellow Sea was exposed during the late Quaternary glacial low-sea l  相似文献   

12.
该文利用圆盘渗透仪,对辽河三角洲湿地4种不同的生境进行渗透系数的测定,并对4种生境的渗透系数进行老人分析比较,作出辽河三角洲湿地渗透系数的分布状况图。从图上可以看出,辽河三角洲湿地渗透系数值最大值为(3.2~3.4)×103cm/s,平均值为1.5×103cm/s。  相似文献   

13.
本文记述的渤海,黄海海底发现的原始牛角心化石(3件),根据形态特征将其定名为Bos primigenius dalianensis subsp.nov.(原始牛大连亚种)。时代屆新生代第四纪晚更新世。这是我国首次于海底发现的原始牛化石。它的发现为探讨晚更新世时期黄海、渤海古地理环境,古气候条件,海水进退,冰期与间冰期的更替,哺乳动物的演化和迁徙提供了新的资料。  相似文献   

14.
Nine Landsat TM tapes and images and MSS images, 10 NOAA tapes and images and 1 SAR image from 1973 to 1997 were used to analyse the diffusion of suspended sediments and the change of tidal radial sand ridges in the northern part of the Changjiang River delta, the South Yellow Sea. The results showed that the diffusion of suspended sediments was controlled by the tide, net current, and submarine topography in this area. The distribution of suspended sediments had close relationship with thesubmarine topography. The old Huanghe River delta and the Changjiang River comprise the main sediment supply for the formation of radial sand ridges, whose evolution can be divided into three stages since the Huangbe River changed its course and flowed northward into the Bohai Sea.  相似文献   

15.
本文对南海壳块第三纪以来所发生的断裂作用、地震活动、岩浆活动与褶皱作用进行了综合研究。在此基础上,总结了南海壳块新构造运动特征并进而对其演化规律进行了探讨。  相似文献   

16.
黄河三角洲高效生态经济区是具有国家战略地位的重要生态经济区,该地区的海岸带地处海陆交接地带,属于陆缘海海岸带,生态环境脆弱,区域海岸带地形地貌系统性阐述甚少。在开展该区域生态地质环境调查的基础上,结合实际调查情况及以往文献的研读,对该地区海岸带地形地貌、岸滩地貌类型及特征进行了系统性归纳总结。整个黄河三角洲高效生态经济区的海岸带地貌分黄河三角洲粉砂淤泥质海岸、莱州湾南岸潍北平原区粉砂淤泥质海岸、莱州砂质海岸3个部分。岸滩类型分为黄河三角洲岸段冲淤平衡潮滩、侵蚀潮滩、淤积潮滩3种及莱州湾岸段侵蚀潮滩及侵蚀砂质海滩2种。  相似文献   

17.
自1855 年黄河改道北行至今,山东省的渤海湾海岸线向海方面推移了19km ,黄河泥沙的造陆面积达2827km2 ,而在江苏省北部从双洋口至小丁港150km 的海岸线上共失去土地1320km2 以上。作者认为,可以疏通明清黄河故道作为引黄工程,利用黄河携带的大量泥沙淤积于黄海沿岸,以减缓黄海岸线的侵蚀,还可抑制黄河泥沙沉积而造成的渤海的淤积。  相似文献   

18.
MODUcTIONThislistof4pisionidspedesisoneofthecontributi0nstothestudyoflittofalmeiofaunaIp0lychaetesfromtheChinesecoast.ThernateriaIswerecoforduringashortexpeditiontoHainanIslandbyProfB.L.Wu,Mr.F.P.HuangandMr.Z.H.ixngoftheFirstInstituteofdrinography,StatedrinicAdndnisttationinQingdaoandProfDr.W.WeStheideandDr.G.PurschkeoftheUniversityofDenabruckinOct0berl99l,additionalmateriaIsweresamPledbyMr.Z.H.Dinginash0rtexpeditiontoHongkonginJanuary1995.Hithert0,onlyPtrionelevisetoSaZhao…  相似文献   

19.
The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in Chi-na. Rail, road and water transportation have competed against each other for container transportation in the Chang-jiang River main line and its delta area. It is of significance to assess these different transportation modes scientifi-cally in order to organize container transportation efficiently in this area and make decision for integral plan and construction of transportation system in this area. This paper outlines application of fuzzy comprehensive evaluation to appraise different modes of typical direction of containers. Twelve assessment indexes were decided. Membership functions were formulated. Evaluation results indicated that road transportation was optimal mode in the Changjiang River delta area, however water transportation was the primary way in the Changjiang River main line.  相似文献   

20.
River discharge can deliver nutrients to the coastal zone and change the hydrologic properties of the water column. Soon after a flash flood from the Yalu River (Northeast China) in August 2010, we investigated the salinity and nutrient concentrations, as well as other environmental conditions in the Changshan Archipelago area, located approximately 100 km west of the river mouth in the northern Yellow Sea. Diluted water was mainly observed in the upper layers shallower than 15 m, with surface salinity between 18.13 and 30.44 in the eastern study area and between 28.16 and 29.72 in the western area. Surface salinity showed a significant negative correlation with concentrations of dissolved nutrients (P < 0.05), but not with that of Chlorophyll-a (Chl-a), dissolved oxygen (DO), particulate materials or pH. The average concentrations of nitrite, nitrate, and silicic acid decreased from the surface layer to bottom layer and were significantly higher in the east area than in the west area (P < 0.05). In contrast, average ammonium and phosphate concentrations were highest in the bottom layer of both areas, with no significant spatial differences. DO varied between 6.06 and 8.25 mg L-1 in the surface layer, and was significantly higher in the eastern area than in the western area in the surface and middle layers. Chl-a concentration was constantly below 4.09 μg L-1. Our work demonstrated the strong influences of Yalu River on proportions of various nutrient components in the Changshan Archipelago area. Silicic acid and total inorganic nitrogen levels were significantly elevated comparing to phosphate in the eastern area. Such changes can potentially induce phosphate limit to phytoplankton growth.  相似文献   

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