共查询到20条相似文献，搜索用时 140 毫秒
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《国土资源遥感》2016,(1)
突发冰川终碛湖(简称"冰湖")溃决泥石流/洪水是西藏高山冰湖分布区的一种山地灾害,极易给下游地区的居民及公路、桥梁、水利水电等基础设施带来毁灭性灾害。多年来,对冰湖溃决泥石流/洪水的研究受到了高度重视;但高山高寒和艰险的地形及交通条件,给冰湖溃决泥石流灾害的实地调查带来不便,大部分冰湖溃决缺乏实时的文献记载资料,而灾后访问资料经常会与实际情况有出入。遥感图像可真实记录冰湖溃决泥石流的形态、位置和发生时间等相关痕迹。因此,利用高空间分辨率Rapid Eye和多时相Landsat MSS,TM图像,对吕儒仁、程尊兰等学者报导的"1982年发生在定结县的冰湖溃决泥石流事件"进行了验证。通过对覆盖金错和印达普错的高分辨率遥感图像解译和灾害发生前后的遥感动态变化分析,认为有关文献记载的"金错冰湖溃决泥石流事件"实际上是印达普错溃决泥石流事件。野外调查发现金错的终碛垄较为完整,其下游部位没有发现大型U型溃口和冲沟,终碛垄下游也未见新泥石流堆积体。研究结果表明,对高分辨率、多时相遥感图像的解译能够有效地提高艰险地区地质灾害调查的准确性。 相似文献
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遥感在地质灾害(滑坡、泥石流)识别方面,较常规方法有明显的优势,并能快速提供大面积地区的位置、分布、范围、规模、类型、发育环境等数据和图件。本文通过多时相、多平台遥感图像解译,了解它们的动态变化及发展趋势,这些信息为工程灾害评价及滑坡、泥石流防治工作提供了全面可靠的依据。 遥感技术在滑坡、泥石流灾害领域中的应用除遥感技术水平外还依赖于滑坡、泥石流信息机制、应用模型的研究及信息系统的支持。 相似文献
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研究目的：探讨快速、准确的提取中国西南地区滑坡、泥石流灾害的新方法。研究方法：本文利用高空间分辨率的Quick Bird图像,突破传统调查方法的限制,发挥其宏观、综合、直观、快速等优点,在Quick Bird图像上详细地图定滑坡和泥石流灾害体的位置及发育范围,结合高程和坡度等基础地理信息,探讨地质灾害发育的空间规律。研究结果：研究表明该研究区内地质灾害以泥石流、滑坡为主。主要沿河及公路等人类活动较密集的区域分布,地质灾害的发生大多受到降雨和工程活动等因素的影响。研究结论：为研究区内的防灾和减灾工作提供重大依据。 相似文献
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浙江省是我国以山地为主的省份之一,素有“七山一水二分田”之称。
近年来,浙江省台风汛期期间小流域集中强降雨引发小流域泥石流等地质灾害频繁发生,造成重大人员伤亡和财产损失。据省国土资源厅调查统计,全省48个县（市、区）共发生沟谷泥石流295起,坡面泥石流数百处,因泥石流灾害死亡497人,造成直接经济损失21255万元。小流域泥石流已成为全省危害最为严重的地质灾害。 相似文献
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由于缺乏相应的多尺度表达与索引机制,灾害模拟数据的三维动态可视化存在难以实时进行、渲染效果差、模式单一等问题。鉴于此,将泥石流灾害模拟数据与虚拟地形环境相结合,重点研究了泥石流灾害模拟数据实时在线发布与多尺度三维动态可视化方法。设计了网络服务总体框架体系,并重点探讨了多尺度数据组织、索引、动态表达等关键技术;选取案例区域研发原型系统,并开展了分析实验。结果表明,该方法能满足泥石流灾害在线实时三维动态可视化要求,也可根据用户对精度和流畅性的偏好与需求,选择相应尺度进行可视化表达。 相似文献
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泥石流灾害突发性强,成灾速度快,危害严重,易给人民生命财产和社会基础建设造成严重损失。本文以甘肃省积石山县2018年8月2—3日泥石流发生时的降雨数据为临界值,结合该地区地形地貌、土壤土质、植被覆盖、水文等环境变量数据,利用GIS技术进行数据分析,发现积石山县刘集乡、石塬乡、大河家镇等为泥石流灾害高危易发区域。引发当地泥石流的原因主要为:①植被破坏严重,土体不稳定,强降雨引起泥石流;②研究区属于黄土高原地貌,水体侵蚀导致极易发生泥石流;③对黄河沿岸破坏较为严重,夏秋汛期,黄河水量猛增,对没有植被保护的土壤剧烈冲刷,为泥石流的发生提供了物质条件。 相似文献
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在前人研究基础上,提出了一种基于SPOT5图像和DEM数据自动提取泥石流的方法。首先利用归一化差值植被指数(NDVI)、归一化差值土壤亮度指数(NDSI)和图像经主成分变换得到的第一主成分(PC1)等3种遥感指数获取新的主成分变换图像,进而利用阈值自动选取算法提取包含泥石流的裸地信息;然后基于1∶10 000的DEM数据,利用改进的沟谷中心线提取算法提取沟谷中心线,并利用数学形态学滤波算法生成沟谷范围;最后将提取的疑似泥石流图斑与沟谷范围匹配,并对矢量化后的结果进行面积、坡度和顺坡性等筛选,得到泥石流或潜在泥石流信息。实验表明,本文构建的泥石流提取模型具有较高的提取精度和效率。 相似文献
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Spectral mapping of rock weathering degrees on granite using hyperspectral DAIS 7915 spectrometer data 总被引：1，自引：0，他引：1
Asuncin Riaza Peter Strobl Ulrich Beisl Andrea Hausold Andreas Müller 《International Journal of Applied Earth Observation and Geoinformation》2001,3(4):345
Rocks are weathered by chemical and physical processes into a mixture of loose material that produces soil. Mineralogical and textural changes are involved, which can be detected by imagery through digital image processing based on rock spectral behaviour as recorded by ground and laboratory spectrometers. Different densities of vegetation cover can be mapped qualifying further evolution of the area in terms of erosion, transport and sedimentation. Hyperspectral imagery helps to map the weathering front and different degrees of weathering on granite rock through mineralogical and textural associations related to the geomorphological processes in the area on various granitic facies. Abundance of feldspar and porfidic texture on the fresh rock are the critical parameters conditioning intensity of weathering in the area. Maps spectrally elaborated gather information on lithologies, mineralogical changes produced by geomorphological processes associated to landforms, topography and climate. Such maps contribute to estimating the spatial controls of erosion, suggesting soil particle size distribution, soil aggregation, soil depth, and consequently, helping to elaborate soil loss and soil conservation maps. 相似文献
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The geologic features indicative of Cu, Pb, Zn mineral deposits in a area are fractures (structure), and host rock sediments. Datasets used include Cu, Pb, Zn deposit points record, geological data, remote sensing imagery (Landsat TM5). The mineral potential of the study area is assessed by means of GIS based geodata integration techniques for generating predictive maps. GIS predictive model for Cu, Pb, Zn potential was carried out in this study area (Weixi) using weight of evidence. 相似文献
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论TM图像在土地利用和农作物布局动态监测中的定位定性精度 总被引：5，自引：1，他引：5
由于经济建设的发展和自然因素的影响,土地利用状况和农作物布局每年都在发生变化,耕 地在减少、农作物布局每年在调整、建设用地不断增加,为及时掌握土地利用和农作物布局的动态 变化,根据全国农业区划委员会的要求,利用TM磁带结合彩红外航片和地图,在北京地区进行 了动态监测研究试验。由1:10万地形图选取平面控制点对TM磁带进行精处理,平面定位精度为 半个象元,精度较高；利用微机多因子自动分类和目视解译对比分析,定性分类精度达94%;TM 图象的多光谱信息丰富,定位定性精度较高,适用于土地利用和农作物布局的动态监测,周期短、 效益好。 相似文献
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S Anbazhagan 《Journal of the Indian Society of Remote Sensing》1991,19(2):135-140
Remote sensing technique can play a vital role in geological, geomorphological and structural studies. Geology and structure of Perungulathur area in Thiruvannamalai Sambuvarayar district was studied by using Landsat imagery and aerial photographs with limited field checks. Charnockite, which forms the country rock of the area, and the interbedded pink granite and amphibolite exhibit typical tonal and textural characters on aerial photographs. The study has brought out a partly exposed structural basin which is represented by the folded structure of amphibolite and pink granite within the charnockitic country rock. 相似文献
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Tarik. B. Benomar BIAN Fuling 《地球空间信息科学学报》2006,9(2):151-156
IntroductionChina is the third richest country in the world ofmineral resources with a total potential value of 11trillion USdollars. Yunnan Provincce is one of theimportant metallogenic belts for nonferrous and pre-cious metal deposits[1].Mineral source … 相似文献
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Gayantha R.L. Kodikara Tsehaie WoldaiFrank J.A. van Ruitenbeek Zack KuriaFreek van der Meer Keith D. ShepherdG.J. van Hummel 《International Journal of Applied Earth Observation and Geoinformation》2012,14(1):22-32
Pleistocene to present evaporitic lacustrine sediments in Lake Magadi, East African Rift Valley, Kenya were studied and mapped using spectral remote sensing methods. This approach incorporated surface mineral mapping using space-borne hyperspectral Hyperion imagery together with laboratory analysis, including visible, near-infrared diffuse reflectance spectroscopy (VNIR) measurements and X-ray diffraction for selected rock and soil samples of the study area. The spectral signatures of Magadiite and Kenyaite, which have not been previously reported, were established and the spectral signatures of trona, chert series, volcanic tuff and the High Magadi bed were also analyzed.Image processing techniques, MNF (Minimum Noise Fraction) and MTMF (Mixture Tuned Matched Filtering) using a stratified approach (image analysis with and without the lake area), were used to enhance the mapping of evaporates. High Magadi beds, chert series and volcanic tuff were identified from the Hyperion image with an overall mapping accuracy of 84.3%. Even though, the spatial distribution of evaporites and sediments in Lake Magadi area change in response to climate variations, the mineralogy of this area has not been mapped recently. The results of this study shows the usefulness of the hypersspectral remote sensing to map the surface geology of this kind of environment and to locate promising sites for industrial open-pit trona mining in a qualitative and quantitative manner. 相似文献
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S. C. Sharma N. Rajendran A. K. Grover G. S. Srivastava 《Journal of the Indian Society of Remote Sensing》1990,18(4):45-64
The paper describes the details of a comparative study of geological interpretations carried out from Synthetic Aperture Radar (SAR) imagery, Landsat MSS (B & W) imagery and Aerial Photographs, covering 2100 sq km of area in Anantapur district of Andhra Pradesh. The area comprises Peninsular—Gneissic Complex and rocks of Dharwar and Cuddapah Super Groups beside the Quaternary alluvial deposits along the Penneru river and its tributaries. Geomorphologically the areas is represented by denudational, fluvial and structural landforms. The study indicates that the details of the geological and geomorphological maps prepared from SAR imagery and aerial photographs are comparable despite the smaller scale of SAR imagery while the same are not exhibited in Landsat imagery mainly due to its low resolution. Although broad lithological units are possible to be discriminated on SAR as well as aerial photographs, some of the finer rock types viz. gabbroic dykes could be discriminated from the delerite dykes in the SAR imagery due to their different surface roughness. Stereoscopic coverage and enhanced micro-relief of SAR imagery gives better geomorphological details in comparison to aerial photographs. A detailed study of lineaments has also been carried out which shows that in SAR imagery there is over-representation of short lineaments due to enhanced micro-relief and radarshadow effects across the look direction and under-representation of lineaments along the look direction. Landsat imagery is perhaps the best for demarcating lineaments of regional magnitude while aerial photographs are good for depicting shorter lineaments. However, certain lineaments seen in SAR imagery are often not continuously seen on aerial photographs. 相似文献