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1.
红水河流域岩溶浸没内涝灾害形成的地学因素分析   总被引:4,自引:1,他引:3  
郭纯青  李文兴 《中国岩溶》1999,18(3):228-233
红水河流域由于多年人类活动和水能资源开发所产生的岩溶浸没— 内涝灾害,在局部范围内比较严重,必须引起高度重视! 据红水河梯级开发与规划电站的修建情况,对红水河干流岩溶区内已发生的浸没— 内涝灾害成因,进行了综合分析。   相似文献   

2.
水淹坝岩溶内涝是安顺市西秀区发育最大范围的岩溶内涝,严重制约了当地经济发展。本文以岩溶地下水系统为单元,通过开展1:10000水文地质调查、地球物理勘探、水文地质钻探等手段,查明内涝所在区的岩溶发育特征、水文地质条件。在此基础上分析得出,水力坡度小、岩层倾角缓造成地下河管道淤塞;人类工程活动使有水落水洞口堵塞,加之广阔的集雨面积和连续的强降雨是造成水淹坝岩溶内涝的主要原因。通过对水淹坝内涝成因分析,为岩溶内涝灾害综合整治提供参考依据。  相似文献   

3.
红水河梯级水电站的百龙滩、岩滩等库区,由于岩溶地下河系统的存在,在水电站蓄水以前,每逢大雨,就会造成库区谷地的浸没内涝,在水库蓄水以后,由于地下河出口水位的提高,使得库区内涝灾害加重,为了研究库区洼地水库蓄水前、后浸没内涝灾害的规律,根据该地区的水文地质条件,组装了物理模型。采用物理(数学)模拟的方法对红水河百龙滩水电站库区的地苏地下河系统进行模拟计算。研究库区凤翔、镇兴、南江谷地在不同的大气降水、不同的地下河出口水位条件下,谷地的内涝水位的变化规律,建立起3个谷地的数学模型,同时,对可能出现的降雨类型进行模型预测。  相似文献   

4.
在我国华南、西南的裸露型岩溶地区, 旱涝灾害频发。这是亚热带湿润气候条件下岩溶地区环境脆弱的一种表现。一些地势较高的峰丛洼地, 由于地表迳流稀缺, 难以修建蓄水工程, 干旱缺水现象较为普遍。而地势较低的岩溶洼地, 谷地和峰林平原, 夏秋雨季, 地下岩溶管道排泄受阻, 经常发生滞洪涝灾, 使农田、村镇周期性受淹。如果修建水库抬高了河水位, 淹没了地下河或泉口, 使库水循地下河倒灌, 顶托了地下河的排泄, 则使岩溶洼地内涝更加严重。此种岩溶地区三水(大气降水、地表水、地下水 )转化现象所导致的内涝灾害, 称之为岩溶浸没内涝。  相似文献   

5.
我国西南岩溶山区地质环境脆弱,人类工程活动强烈,群死群伤的灾难性滑坡频发,造成严重的人员与财产损失。文章概述了西南岩溶山区大型崩滑灾害基本特征和防灾减灾的难点,提出了目前研究中亟待解决的关键科学技术问题,包括岩溶地质结构与管道流的相互孕灾机理、地下采动下大型崩滑灾害形成机制、灾害高位远程动力成灾模式、灾害早期识别与空间预测。针对这些问题,文章提出如下研究思路:通过多学科联合,重点研究岩溶山区大型崩滑灾害链的孕育发生规律与成灾模式,揭示岩溶管道-裂隙-孔隙地下水动力作用及孕灾过程和地下采动、库水波动等工程扰动环境下山体劣化损伤效应,构建岩溶崩滑灾害高速远程动力致灾机制与风险预测方法,形成早期识别、监测预警与综合防控技术及示范,为我国岩溶山区城镇化建设、重大工程安全运营提供科技支撑。  相似文献   

6.
岩溶地下水污染风险评价对岩溶地下水的保护、管理和合理利用具有重要意义。文章总结了近年来国内外地下水污染风险评价方面的研究进展,针对目前评价体系存在的不足,构建了适合岩溶区地下水污染风险评价体系。该方法基于欧洲模式,实现地下水防污性能评价;污染负荷评价则考虑污染物在覆盖层中的衰减过程,利用折减系数实现污染负荷量化;最后,基于GIS空间叠加分析耦合防污性能与污染负荷评价,实现区域地下水污染风险评价。文章以地苏地下河系流域为例,开展岩溶区域地下水污染风险评价,结果表明:区域整体地下水污染风险偏低,地下水中等及以上污染风险区域面积424.41 km2,占研究区总面积的39.03%,主要分布在研究区中东部地苏乡、东庙乡、六也乡局部等人类活动频繁与地苏地下河干流中下游段。地下水污染风险空间分布特征不仅显示了岩性、坡度、岩溶网络发育等自然条件对评价结果的影响,同时也反映了人类活动的影响。地势平缓,岩溶发育程度强烈,加之人类活动频繁是导致区域地下水污染风险较高的原因所在。  相似文献   

7.
水库周边岩溶浸没——内涝灾害研究   总被引:4,自引:2,他引:2  
水库周边岩溶浸没——内涝现象是水利水电建设的环境问题之一。八十年代以来,已在若干水库发生了此类现象,造成了一定的经济损失。本文以红水河岩滩水电站库区的内涝为典型事例,分析了岩溶浸没内涝的主要原因和形成条件。指出需要加强调查、观测、模拟试验研究等工作的重要性   相似文献   

8.
岩溶塌陷是山东省临沂市区最重要的地质灾害类型,一旦发生,会带来较大的经济和财产损失,因此对岩溶塌陷的风险评价十分必要。风险评价包括现状评价和预测评价,主要分3个步骤来完成:危险性评价,易损性评价和期望损失评价。利用地下水流模型确定调采方案下的相关评价因子,预测了岩溶塌陷的风险性。通过比较发现,经过地下水调采后,原岩溶塌陷高风险区范围大为缩小。地下水流数值模型和风险评价方法结合,可以确定合理的岩溶水规划开采方案,对于指导和防治岩溶塌陷具有重要意义。  相似文献   

9.
岩溶塌陷是山东省临沂市区内最重要的地质灾害类型,由于研究区人口和工矿企业分布集中,社会结构和基础条件多样,岩溶塌陷一旦发生,可能带来的经济和财产损失较严重,本文尝试采用易损性和期望损失评价确定可能遭受岩溶塌陷灾害的各类承载体空间分布与破坏损失率,依据预测塌陷可能造成的破坏损失程度,确定岩溶塌陷的风险分区,以期通过对风险级别较高的地区适时发布岩溶塌陷预警信息,并采取科学的防治方法和应急处理措施,达到降低岩溶塌陷风险和危害的目的,为科学开展岩溶塌陷预警和防治提供参考依据,为国内岩溶塌陷防治工作提供借鉴。  相似文献   

10.
关于岩溶浸没性内涝灾害初探   总被引:10,自引:0,他引:10  
发生于岩溶峰丛洼地和峰林谷地中的岩溶浸没性内涝是一种地质灾害,具有范围大,频次高的特点,对农业生产危害极大,急待治理,本文以若干内涝片的典型事例分析了岩溶浸没性内涝的主要成因,归纳了“降雨、洪水、岩溶管道”三要素,初步提出了若干治理措施。  相似文献   

11.
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   

12.
13.
Chronological analyses of correlations between certain global repeating events (mass extinctions of marine organisms, meteorite impacts, and flashes in the frequency of geomagnetic reversals) during the Phanerozoic Eon and the motion of the solar system in the Galaxy are presented for five rotationally symmetrical models for the regular Galactic gravitational field. Thirteen of sixteen mass-extinction events can be described by a repetition interval of 183±3 million years. This is in agreement with the anomalistic period (interval between two subsequent passages of the Sun through the apocenter of its Galactic orbit) in the model of Allen and Martos. The positions of the minima and maxima in Gaussian functions approximating the frequency distribution for geomagnetic reversals also agree with the times of passage of the Sun through the apocenter and pericenter, respectively, of its Galactic orbit in this model. The maximum in the distribution of the deviations of the dates of mass extinctions from the nearest dates of impacts of large, crater-forming bodies is close to zero, providing evidence that many such events are correlated. As a rule, extinctions follow impact events. The impacts of large bodies have occurred most often when the solar system passes through the Galactic plane, while mass extinctions occur more often at some distance from the Galactic plane (about 40 pc). As a rule, intervals of increases in the frequency of geomagnetic reversals coincide with dates of impacts of large bodies. At the same time, these intervals do not show a clear correlation with the dates of mass extinctions. The intensity of mass extinctions, like the energy released by impacts, is consistently higher in periods when the Sun is moving from the apocenter toward the pericenter of its orbit, than when it is moving from the pericenter toward the apocenter. Thus, there is evidence for a variety of relationships between repeating global events in the Phanerozoic and the motion of the Sun in the Galaxy. Long-period variations in the frequency of geomagnetic reversals are correlated with the orbital motion of the Sun, and increases in the frequency of geomagnetic reversals are correlated with impacts. Mass extinctions are correlated with the impacts of large bodies, whose motions may have been perturbed by clouds of interstellar material concentrated toward the Galactic plane and by the shock front associated with the Perseus spiral arm, through which the solar system passes. The velocity of the Sun relative to the spiral pattern is estimated.  相似文献   

14.
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   

15.
从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返   总被引:4,自引:1,他引:4       下载免费PDF全文
位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压,而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩,榴辉岩及其他直接围岩皆呈包体存在于其中,并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体,表明新元古代花岗岩的组成物质也经受过超高压变质作用,且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次(或阶段)却少于榴辉岩。椐上述可得如下推断:超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部(俯冲板块前部)形成的;榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的,其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升,遭受剥蚀。  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.
摩擦桩基桩土间极限摩阻力取值问题探讨   总被引:1,自引:0,他引:1  
陈银生 《世界地质》1999,18(1):54-59
通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。  相似文献   

18.
19.
We first re-examined the apparent polar wander curves for stable Eurasia and Africa since the Triassic. These curves were then combined together with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given. Then, most of the paleomagnetic results from the Tethys mobile belt, from the Atlantic to the Pamirs, were analysed.Several groups of plates, microplates and blocks can be seen. First, relatively stable regions like Maghreb and Sicily, which have not moved much. Then we have a group formed by Iberia, Sardinia, Italy and, to a lesser extent, Corsica and the Western and Central Alps. For these blocks, movements are anticlockwise rotations chiefly driven by the anticlockwise rotation of Africa, but they are sometimes stronger.To the east, a major change takes place. The north of the Aegean Sea and the Ionian zone are clockwise rotated and these rotations are recent: Oligocene-Miocene for the first part, Pliocene to the present for the second part.A major problem arises in Turkey, Caucasus and Iran. Paleomagnetic results indicate a position far to the south of Eurasia, and, at the same time, geological evidence is in favour of a position close to Eurasia. We discuss these discrepancies.  相似文献   

20.
The structure of the eastern Pyrenees consists mainly of south-directed thrusts involving basement and cover rocks. An antiformal stack developed by the piling up of basement thrust sheets which outcrop in the Axial zone. These structures account for a thin-skinned thrust model rather than a vertical fault model in which the Axial zone would be essentially autochthonous, and the North-Pyrenean fault the axial plane of a fan thrust system. New data from the Eastern Pyrenees and the thin-skinned model suggest that(1) the structure east of the Pedraforca nappe is similar to that of the Central Pyrenees; (2) the cover rocks of the South-Pyrenean units and of the Axial zone-after restoration—built up a northwards-thickening prism consistent with the existence of a unique Pyrenean sedimentary basin during Mesozoic time; (3) the Axial zone is only a complex antiformal stack developed as a part of South-Pyrenean system related to the Paleogene thrusting-tectonics. The Axial zone palaeogeographic area had no special meaning during Mesozoic time.  相似文献   

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