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1.
根据历史记载、遥感资料解释和野外现场调查,对长江湖口一彭泽县段江岸冲淤变化,及江中主要江心洲的变迁进行研究,该江段历史变化较复杂,但是总体是河流主流的“S”摆动,主流不断南迁总体南岸以侵蚀为主,北岸以淤积为主,在棉船洲地区由于该洲向北生长,则以北岸侵蚀为主。最后分析江岸变化对防洪安全的影响,江岸变化是重要的致灾因子。 相似文献
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基于遥感与GIS技术,利用高空间分辨率遥感卫星SPOT-5和GF-2影像数据,对海南岛西北部地区海口市南渡江—东方市2005年和2016年2个时期的海岸线进行人机交互解译,并对其10 a来的时空变化特征进行了分析。结果表明: 10 a间,海南岛西北部海岸线时空变化显著,主要影响因素为人工开发建设; 人工海岸线增幅达到113%,其占比由2005年的24.3%上升至2016年的51.6%; 除部分淤泥质海岸线和砂质海岸线转化为人工海岸线外,自然海岸线以侵蚀为主,局部地区有少量淤积。不同地区海岸线变化特点不同: 儋州市和澄迈县海岸线资源丰富,开发力度较大; 临高县和昌江黎族自治县自然海岸线以侵蚀为主,淤积少; 东方市和澄迈县海岸线侵蚀较少,较易淤积。分析结果可为海南岛西北部海岸线调查、开发和保护提供一定的科学依据。 相似文献
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《上海国土资源》2014,(2)
人类活动对我国海湾生态环境的影响日趋严重,作为海湾变化的重要表征—海湾岸线自然成为陆海相互作用研究的主要内容之一。本文以西部大开发的前沿—北部湾海湾岸线为对象,利用Landsat系列影像反演1991、2005及2010年北部湾1595km的大陆岸线;选择1991~2010年间北部湾北部变化强烈的40个岸段,分析岸线的冲淤变化。结果表明:北部湾海湾曲折岸线的固有属性已发生改变,岸线平直化趋势明显;海湾岸线冲淤交互存在,相对遮蔽的岸段岸线积极向海推进,年淤积速率为23m/a,无防护地带的岸线以侵蚀为主,年平均侵蚀速率为24m/a;在不同类型的海湾岸线中,生物海岸与砂质海岸表现为向陆蚀退,年平均侵蚀14m/a,淤泥质海岸为向海淤积,年平均淤积速率为9m/a,基岩海湾岸线变化不大。 相似文献
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利用海南博鳌海域2期海图,结合多期遥感影像和地形图对比,分析了博鳌海域的冲淤及海岸线变迁;根据博鳌港潮汐汊道纳潮量P和口门断面面积A之间的P-A关系研究和冲淤灾害因素判别,进行了口门稳定性评价,并对博鳌港的冲淤灾害和环境稳定性进行了分析.结果显示:博鳌港外海区域以淤积为主;万泉河口门海域以侵蚀为主,口门呈现单口门和双口门交替变化状态,口门北侧和玉带滩北部岸线主要以侵蚀后退为主,玉带滩中部和南部岸线近于稳定平衡态;沙美内海以淤积为主.采用潮汐汊道P-A关系进行分析,显示博鳌港口门处于不稳定状态. 相似文献
5.
林军 《中国地质灾害与防治学报》2005,16(2):32-37
河流或流水的侵蚀淤积是改造地质环境的最重要因素之一。利用遥感技术和时空对比分析等监测手段来揭示地质环境的这种快速变化，以及对人类生存环境所产生的深远影响是未来环境地质研究的热点和难点问题。近年来随着城市堤防和护岸工程的逐步完善，河流侵蚀淤积作用强度，在一定程度上得到了缓解。但河流的侵蚀淤积地质作用仍占主导地位，由其引发的环境地质问题仍需进一步深入研究。地质构造作用，控制河流的走向和流势；河流水文特征，决定河流地质作用的主要时期；河谷地貌形态，可以改变河流的侵蚀、淤积作用性质；岸坡岩土性质。影响河流沿岸边坡的稳定性；人类工程活动，改变了河流的自然形态和水文泥沙过程，导致新的河床冲淤变化。河流侵蚀淤积环境地质问题主要表现在：(1)河岸侵蚀岸线后移，危及岸边居民建(构)筑物，以及交通、能源、农田、水利等公共设施的安全；(2)河床淤积河道变浅，排洪、泻洪能力下降，影响航运并造成洪水泛滥；(3)河口淤积造成港湾功能的严重退化，影响港口城市的可持续发展。 相似文献
6.
以实地调研资料为依据,对苏中黄海岸带的侵蚀、淤积作出系统分析。将苏中岸段分为北侵蚀、南淤积两大段,射阳河口以北的面大套河口为侵、淤转换中介点。作者从地貌形态、地层岩性(结构构造为主)、入海河口与风浪组合的水动力条件着眼,对侵、淤形成机制作了简要分析,并对发展趋势作出了概略预测,最后针对岸带侵、淤特点,提出岸带保护措施及滩涂资源开发利用方向。本文可供海岸滩涂资源开发利用规划及地质灾害防治参考利用。 相似文献
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影响珠江三角洲可持续城市化发展的若干环境地质问题 总被引：7，自引：1，他引：6
珠江三角洲经济区城市化进程迅猛。环境地质问题是快速城市化进程的“副产物”、泛都市化趋势下人一地一生相互关系失调的反映。对可持续城市化进程具有广泛影响的主要环境地质问题有软土区地面形变,海岸异常变迁衍生的港口、河道、口门淤积和城市洪涝,水土污染,水质性缺水,构造稳定性和隐伏岩溶塌陷,按成因类型可分为原生为主型、次生为主型、原生与次生结合型3类环境地质问题。可持续城市化的关键之一在于科学利用环境资源,降低环境地质问题的风险。鉴于城市化决策和实践忽视城市地学工作成果的应用和城市地学工作系统性不足,建议尽快系统地开展以环境地质为主体的城市地学工作。 相似文献
9.
土壤侵蚀导致土地退化,破坏土地资源,同时带来严重的泥沙淤积,也是导致生态环境恶化最严重的问题。土壤侵蚀过程虽以渐发性为主,但随着侵蚀的加剧和生态环境的恶化,量变可以导致质变,引起突发性自然灾害。渐发性的土壤侵蚀不被及时防治,最终必然导致突发性自然灾害的发生。为了减轻自然灾害和预防其严重发展,必须及时防治和预防土壤侵蚀,保持和恢复良好的生态环境。 相似文献
10.
针对三峡蓄水运行后的泥沙淤积问题,基于实测资料,采用输沙率法和断面法分析了三峡水库运行初期的泥沙淤积特点.结果表明:三峡水库2003—2013年泥沙淤积总量为15.31亿t,平均排沙比为24.5%,均较论证阶段降低;库区泥沙淤积主要分布在常年回水区的宽谷和弯道河段,宽谷段全断面发生淤积、弯道断面流速较小一侧淤积、峡谷无累积性淤积;常年库区近坝段泥沙淤积速度逐年减小,而上段泥沙淤积速度则呈增大趋势;淤积物粒径沿程分选不明显,常年回水区淤积物中值粒径多在0.01 mm以下.库区峡谷段深泓线无明显变化、尚未出现泥沙淤积三角洲、库尾泥沙淤积上延和尾水抬高不明显,据此初步推断峡谷河段存在富余挟沙力而成为局部侵蚀基准面,整个库区将无统一平衡比降的趋势. 相似文献
11.
东濮凹陷北部沙三中亚段广泛发育盐岩和烃源岩,这两个看似不能共存的物质却在这里互层共生。该时期研究区沉积特征为多盐韵律与多层烃源岩互层共生、连续沉积,单个盐韵律厚度从几米到十几米,烃源岩有机质丰度高、类型好。平面上,两者在湖盆沉积沉降中心共生;垂向上,高有机质丰度、好干酪根类型与高盐度地层具有较好的对应关系。因而成为恢复古气候和古环境的重要研究对象。通过岩石学、古生物学以及Sr/Ba、B/Ga、(V+Ni+Mn)、Fe/Mn、Sr/Cu、Mg/Ca、V/(V+Ni)、稀土元素含量和氯同位素等方法对凹陷北部沙三中亚段的沉积环境进行研究。结果表明,凹陷北部沙三中亚段为深水沉积的还原环境,古盐度较高,达到半咸水-咸水沉积;微量元素和孢粉化石特征表明研究区沙三中亚段为温暖潮湿的环境。 相似文献
12.
The Importance of the Precipitation and the Susceptibility of the Slopes for the Triggering of Landslides Along the Roads 总被引：3，自引：1，他引：2
Clemente Irigaray Francisco Lamas Rachid El Hamdouni Tomás Fernández José Chacón 《Natural Hazards》2000,21(1):65-81
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning. 相似文献
13.
郯庐断裂南段研究进展与断裂性质讨论 总被引：13，自引：3，他引：13
据1：5万区域地质调查和专题研究资料，就郯庐断裂带是否南延与消失的原因，其与大别—苏鲁造山带交截形成的假位错效应，以及与中新生代沉积盆地形成演化的关系等作了新的阐述。在此基础上，讨论了郯庐断裂带是否为巨大的左行平移断层或转换断层。认为郯庐断裂带可能是在“古郯庐带”的基础上于早侏罗世重新活动、白垩纪强烈活动的地堑型枢纽断裂带。 相似文献
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15.
Guboglo M. N. 《GeoJournal》1980,4(1):53-58
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen. 相似文献
16.
某高速公路下伏煤矿采空区稳定性分析 总被引：10，自引：0，他引：10
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。 相似文献
17.
Jiayu Rong Michael Melchin S. Henry Williams Tatyana N. Koren Jacques Verniers 《《幕》》2008,31(3):315-318
The Global Stratotype Section and Point （GSSP） for the base of the Silurian System was defined in 1985. Since that time, a number of researchers have suggested that this section has serious deficiencies for use as a GSSP. As a result, in 2000, the Subcommission on Silurian Stratigraphy （SSS） proposed undertaking a formal restu@ of this GSSP, which was subsequently approved by the International Commission of Stratigraphy （ICS）. The result of this restudy was the formal proposal that the current GSSP, at 1.6 m above the base of the Birkhill Shale, at Dob＇s Linn, Scotland, should be maintained as the same locality and stratigraphic level, but the bios- tratigraphical definition of the boundary should be revised. The previously defined, basal Silurian grapto- lite zone, the Parakidograptus acuminatus Zone, should be subdivided into a lower Akidograptus ascensus Zone and a higher E acuminatus Zone. The base of the A. ascensus Zone, marked by the first appearance of A. ascensus, should be regarded as the biostratigraphic mark for the base of the Silurian. This proposal has now been formally approved by the SSS and ICS, and ratified by International Union of Geological Sciences. This is the first GSSP to undergo formal restudy and redefini- tion, and the proposal also included a recommended procedure for restudy of GSSPs. 相似文献
18.
Dean S. Oliver 《Mathematical Geology》1998,30(7):911-933
In reservoir characterization, the covariance is often used to describe the spatial correlation and variation in rock properties or the uncertainty in rock properties. The inverse of the covariance, on the other hand, is seldom discussed in geostatistics. In this paper, I show that the inverse is required for simulation and estimation of Gaussian random fields, and that it can be identified with the differential operator in regularized inverse theory. Unfortunately, because the covariance matrix for parameters in reservoir models can be extremely large, calculation of the inverse can be a problem. In this paper, I discuss four methods of calculating the inverse of the covariance, two of which are analytical, and two of which are purely numerical. By taking advantage of the assumed stationarity of the covariance, none of the methods require inversion of the full covariance matrix. 相似文献
19.
Deviation of the major axis of the inertia ellipsoid of the Moon from the direction toward the Earth
B. P. Kondratyev 《Astronomy Reports》2017,61(8):709-714
It is known from observations that the center of mass of the Moon does not coincide with the geometric center of its figure, and the line connecting these two centers is not aligned with the direction toward the center of the Earth, instead deviating toward the Southeast. This stationary deviation of the axis of the inertia ellipsoid of the Moon to the South of the direction toward the Earth is analyzed. A system of five linear differential equations describing the physical libration of the Moon in latitude is considered, and these equations are derived using a new vector method taking into account perturbations from the Earth and partly from the Sun. The characteristic equation of this system is obtained, and all five oscillation frequencies are found. Special attention is paid to the fifth (zero) frequency, for which the solution of the latitude libration equations are stationary and represents a previously unknown additional motion of the rotational axis of theMoon in a cone with a small opening angle. In contrast to the astronomical precession of the Earth, the rotation of the angular-velocity vector is in the positive direction (counter-clockwise), with the period T 3 = 27.32 days. On this basis, this phenomenon has been named “quasi-precession.” This quasi-precession leads to a stationary inclination of the major axis of the inertia ellipsoid of theMoon to the South (for an observer on Earth), making it possible to explain one component of the observed deviation of the center of mass of the Moon from the direction toward the Earth. The opening angle of the quasiprecession cone is approximately 0.834″. 相似文献
20.
正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the 相似文献