首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 193 毫秒
1.
江达县地处怒江、金沙江及澜沧江三江构造带,地质构造条件复杂,河流切割强烈,山高谷深,斜坡陡峻,地质灾害多发。尤其是2013年以来,昌都及其周边多次发生地震,诱发以白格滑坡为典型的滑坡、崩塌和泥石流灾害,2017年7月8日,更是发生了洪灾泥石流灾害。开展觉布寺沟泥石流发育特征及防治对策研究,对研究昌都地区地质灾害发生发育规律,提高地质灾害防灾减灾能力提高有着重要意义。  相似文献   

2.
喜马拉雅山东南地区地质灾害发育规律初步研究   总被引:2,自引:0,他引:2  
利用遥感手段,结合MapGis,研究了喜马拉雅山东南地区地质灾害的发育情况,发现本区发育的主要地质灾害有滑坡、崩塌、泥石流、冰湖以及堰塞湖。其中崩塌、滑坡、泥石流斜坡地质灾害是本区最重要的地质灾害类型,占到总灾害数量的95.3%。在此基础上对喜马拉雅山东南地区地质灾害发育规律初步研究,发现本区地质灾害的发育在空间上的分布并非均匀,而是具有丛集性的特点。滑坡灾害主要发育在隆子和朗县。泥石流灾害比较严重的有米林、隆子和洛扎3县,而崩塌则主要集中在隆子县。研究发现,本区滑坡发育与地层、地形坡度以及土地类型关系密切,其中修康群、日当组和念青唐古拉群是本区的易滑地层。涅如组由于面积大,其中发育的滑坡较多,但是滑坡的发育率只略高于本区的平均水平。统计表明,16~30的坡度范围是滑坡最容易发生的。大于45以上的坡段很少发生滑坡。灌木林和天然草地这两种土地类型滑坡发育率最高。对于泥石流,研究表明,涅如组中泥石流发育面积最大,发育率也最高。泥石流发育的最适宜坡度也是16~30这样一个坡度范围。冰川和永久积雪区则最易发生泥石流。崩塌发育与地层类型、坡度的关系较为密切,崩塌主要发育在涅如组中,并且集中在坡度大于60以上的陡坡段中。这些初步成果的取得,是以后进行该区地质灾害空间预测的基础。  相似文献   

3.
近年来,受全球气候变暖和城市扩张进程中的人类社会经济活动影响,青海省突发性、局地性地质灾害事件频发。为积极应对地质灾害严峻形势,保障人民生活生产安全、巩固防灾减灾成果、提出科学合理的应对措施。文章以1990—2019年青海省滑坡崩塌泥石流灾害为研究对象,通过数理统计,分析研究了30年间青海省滑坡崩塌泥石流灾害发育特征、时空分布规律及主要引发因素。结果表明:①灾害规模多为小型,灾害类型以滑坡为主。②时间上,多发生在5—10月;空间上,主要发生在地形复杂的青东地区西宁市和海东市。③降雨和开挖边坡是主要引发因素。④近年来,滑坡崩塌泥石流灾害增加趋势明显。研究结果对于今后一段时期青海省地质灾害防范工作具有指导和借鉴意义。  相似文献   

4.
通过对耿马县内威胁人民生命财产的隐患点和灾害点进行野外实地调查,获取第一手资料,对耿马县内地质灾害的分布规律进行了研究。耿马县内发育各类地质灾害144处(条),灾害类型齐全。其中滑坡118处,崩塌18处,泥石流沟2处、地裂缝和地面塌陷各3处,以滑坡为主,其次为崩塌。零星发育泥石流、地裂缝和地面塌陷。区内地质灾害在空间上具有点状产出、线状延伸、局部集中发育的特点;总体上不同地质灾害发育明显受地形地貌影响。夏季强降雨是区内地质灾害的主要诱因;地层岩性控制地质灾害类型;耿马盆地内的滑坡直接受新近系灰、浅灰色粘土岩、砂质粘土岩的膨胀性控制,降雨和人类经济工程活动是滑坡发生的直接诱因。  相似文献   

5.
石玲  王涛  辛鹏 《地质力学学报》2013,19(4):351-363
根据近7年来陕西省宝鸡市12区县地质灾害详细调查资料,总结宝鸡地区地质灾害主要类型、空间分布规律、发育特征及其危害性。研究结果显示,宝鸡市地质灾害发育类型主要包括滑坡、崩塌、泥石流及不稳定斜坡等4类,总体发育特征具有群发性、突发性、周期性和链生性。其中,滑坡和崩塌数量多、危害大,泥石流相对发育较少,不稳定斜坡多与崩塌相伴生,大多发展为崩塌灾害。每年汛期在强降雨作用下,都可能诱发表层小型滑坡和崩塌,特别是城镇居民房前屋后的小型黄土滑坡和崩塌,以及山区公路切坡导致的残坡积层滑坡崩塌频繁发生,是宝鸡市地质灾害群测群防和减灾防灾关注的重点。  相似文献   

6.
通过对耿马县内威胁人民生命财产的隐患点和灾害点进行野外实地调查,获取第一手资料,对耿马县内地质灾害的分布规律进行了研究。耿马县内发育各类地质灾害144处(条),灾害类型齐全。其中滑坡118处,崩塌18处,泥石流沟2处、地裂缝和地面塌陷各3处,以滑坡为主,其次为崩塌。零星发育泥石流、地裂缝和地面塌陷。区内地质灾害在空间上具有点状产出、线状延伸、局部集中发育的特点;总体上不同地质灾害发育明显受地形地貌影响。夏季强降雨是区内地质灾害的主要诱因;地层岩性控制地质灾害类型;耿马盆地内的滑坡直接受新近系灰、浅灰色粘土岩、砂质粘土岩的膨胀性控制,降雨和人类经济工程活动是滑坡发生的直接诱因。  相似文献   

7.
河北省顺平县位于太行山东麓,主要发育有崩塌、滑坡、泥石流、地裂缝等四种类型地质灾害。基于该县地质灾害发育特征,采用GIS技术和信息量数学评价模型,选取坡度、起伏度、坡向、工程地质岩组、归一化植被指数(NDVI)、与河流的距离6个评价因子,对顺平县地质灾害进行易发性评价。评价结果显示:高易发区面积约为125 km2,占全县总面积的17.5%,分散分布于西北部的中低山和丘陵地区,密集发育崩塌灾害,少量发育滑坡、泥石流灾害;中易发区面积约为200 km2,占全县总面积的28.0%,成片分布于西北部的中低山和丘陵地区,少量发育崩塌、滑坡、泥石流灾害;低易发区面积约为389 km2,占全县总面积的54.5%,主要分布于东南部的平原地区及西北部丘陵地区内的宽阔沟谷,沿古河道发育地裂缝灾害,个别地区发育崩塌、滑坡灾害。   相似文献   

8.
河南省卢氏县地质灾害类型主要有不稳定斜坡、滑坡、崩塌和泥石流等。依据2013年卢氏县地质灾害详细调查资料,阐述了该地区地质灾害的主要类型、发育特征以及在时空上的分布特征;对该地区地质灾害发育的主要影响因素进行了较为系统的分析,总结了地质灾害的成因机制;为有效预防灾害发生和减轻灾害损失,提出了地质灾害防治措施。  相似文献   

9.
受"8·8"九寨沟地震影响,沙坝沟小流域内诱发新增大量山体崩塌、滑坡等次生地质灾害,松散物源量急剧增加,极大加剧了泥石流灾害的发生,对沟口聚居区及旅游设施等构成严重威胁.通过分析沙坝沟小流域震后地质灾害发育基本特征,分析研究主沟泥石流形成特征、灾害史及发展趋势,按照地震灾后恢复重建规划,提出了结合地方发展规划的防治方案...  相似文献   

10.
青藏高原的快速隆起使其地质、地貌和气候发生了剧烈变化,导致崩塌、滑坡、泥石流、岩屑流和冰湖溃坝等地质灾害频发。利用遥感技术对青藏高原西部地质灾害的分布、形成条件进行了研究,对灾害形成的背景进行了探讨。崩塌、滑坡和泥石流主要发育于喜马拉雅山、冈底斯山、喀喇昆仑山及昆仑山的高山峡谷之中; 冰湖一般分布于雪线附近; 岩屑流发育在雪线之下基岩裸露区的陡坡上; 融冻泥流则位于海拔更低的多年冻土和季节性冻土的过渡地带。高原内部的造山带为灾害提供了地形条件; 冰川和大气降水为灾害提供了水源; 冰川作用和频繁的融冻作用为灾害提供了物源。青藏高原的快速隆升是地质灾害发育的内因,高海拔高寒气候是灾害发育的外因。  相似文献   

11.
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.  相似文献   

12.
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提  相似文献   

13.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

14.
本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。  相似文献   

15.
本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。  相似文献   

16.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.  相似文献   

17.
18.
Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km2 and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world.  相似文献   

19.
《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).  相似文献   

20.
We have developed a set of four synthetic standards for the rare earth and high field strength elements designed for use in the determination of those elements in silicates. The base material is a glass nominally at the eutectic of the MgO-Al2O3-SiO2 ternary system. The nominal doping level was 2 wt% of the elements as oxides. To avoid problems associated with peak interference, the elements were doped in four separate glasses.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号