共查询到20条相似文献,搜索用时 140 毫秒
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武陵源砂岩峰林的自然属性与地质美学价值 总被引:4,自引:0,他引:4
论述张家界市武陵源砂岩峰林世界地质公园形成砂岩峰林的地质背景和物质基础,探讨诸如产状平缓的构造部位,高角度裂隙和垂直节理的发育,新构造运动的抬升等地质构造条件对砂岩峰林地貌的控制作用,分析砂岩峰林的自然属性(典型性、系统完整性、自然性、优美性、稀有性),阐述砂岩峰林在美学和科考方面的价值和意义。 相似文献
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下地——哈达吐——杨树沟银铅锌多金属矿区地处大兴安岭中南段主峰成矿带,区域成矿地质背景优越,异常组合好,是寻找大型矿床的有利地区。 相似文献
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由广东省地质学会、香港地质学会、广东省地质调查局、中山大学地球科学系联合主办的粤港珠江口地区地质研讨会于2006年11月23-24日在中山大学举行。粤港地质界、地理界80余位专家出席了会议。中山大学、广州大学等30多位研究生、大学生列席聆听学术报告。35位粤港地学家在会上作了学术报告,研究范围涉及地层、构造、城市地质、海洋地质、第四纪地质、环境地质、工程地质、水文地质、矿产地质、风暴潮沉积、第四纪沉积、地下埋藏古树、地质灾害等地学领域。《广东地质》为大会出了《专辑》(《广东地质)22卷1期)。与会者饶有兴趣听取和观看了香港同行关于2004年圣诞节印度洋强烈地震引起海啸的地质效应及其对香港及珠江三角洲的启示的实地考察报告和现场录像。 相似文献
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Landslide susceptibility mapping by correlation between topography and geological structure: the Janghung area, Korea 总被引:7,自引:0,他引:7
The purpose of this study is to develop and apply the technique for landslide susceptibility analysis using geological structure in a Geographic Information System (GIS). In the study area, the Janghung area of Korea, landslide locations were detected from Indian Remote Sensing (IRS) satellite images by change detection, where the geological structure of foliation was surveyed and analysed. The landslide occurrence factors (location of landslide, geological structure and topography) were constructed into a spatial database. Then, strike and dip of the foliation and the aspect and slope of the topography were compared and the results, which were verified using landslide location data, show that foliation of gneiss has a geometrical relation to the joint or fault that leads to a landslide. Using the geometrical relations, the landslide susceptibility was assessed and verified. The verification results showed satisfactory agreement between the susceptibility map and the landslide location data. 相似文献
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红层高悬台地"顶平、身陡、谷深",具有独特的水文地质特征和地下水富集规律。依据以抗旱打井取得的数据、资料并结合前人已有成果,探讨红层高悬台地在不同地形地貌和地质构造条件下的地下水赋存特点,显示地貌形态与地质构造协调控水。台地中部尤其是沉积盆地边缘,是抗旱找水打井的有利地段。台地边缘地下水可采资源和储存量较少,但在局部地貌汇水有利部位和构造发育地段,可形成局部富水块段,因而应按"贫区中找富块,贫块中找富点"的思路,寻找微型、小型储水构造,找准补给、径流、排汇和含、隔水层关系,准确定位、打井找水。受地形地貌条件所限,红层高悬台地尤其是边缘地带地下水位埋藏较深,宜尽量打深井揭至侵蚀基准面以下,才更有可能多出水。 相似文献
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本文在实地考察的基础上,结合前人资料,对研究区内的地质矿产作了较为系统研究,揭示出地质构造演化对成矿作用的控制,并对潜在地质矿产资源进行了论述,为该地区的综合开发规划提供地质矿产依据。 相似文献
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Human activity has been recognized to be an important geomorphic agent, and the resulting changes to landforms and land cover are regarded as a global problem. Although there has been much research into the relationships between geomorphic processes and types of land use such as agriculture, mining, and urbanization, it is important to clarify spatiotemporal human impacts on topography on a regional scale when predicting future changes in land cover.This study examined changes in land use to clarify the distribution and impact of anthropogenic changes to landforms, as well as the influence of geology on the extent of these changes. In a case study from Fukuoka Prefecture, Japan, changes in land use over the last century were analyzed using a geographic information system (GIS). The study area, which covers approximately 4930 km2, has experienced urban development since 1950 and has a current population of over 5 million. Land use data were prepared using paper-based early editions of topographic maps. Subsequently, the distribution of anthropogenic landforms was evaluated by comparing landforms with regional geological data.GIS analysis using our prepared land use data, landform data, and regional geological data has clarified the following characteristics of the study area. (1) Land uses prior to 1950 were constrained by topographic relief. After 1950, land use was characterized by urban sprawl. Urban areas expanded and contained both higher elevations and steeper slopes at their margins. The relationships between land uses and landforms during this urbanization are unclear. (2) The area of urban land increased in the geological regions with Paleogene sedimentary rocks (PSD) and Mesozoic granitic rocks (GR) during the 20th century. The largest coal mining area in Japan was located in the PSD geological regions, and ancient iron working was common in the GR geological regions, particularly during the 7th century. This result indicates that the land use distribution, especially urban areas in sloping terrain, is related to the regional geology. (3) Deforestation related to land use resulted in steeper terrain in forest land in the PSD and GR geological regions. These changes to landforms in forest areas occurred as a result of rapid urban sprawl and have created many new boundaries between forest areas with steeper slopes and urban areas with gentler slopes. This phenomenon may have caused an increase in the frequency of sediment-related disasters.This case study indicates that predictions of anthropogenic changes to landform, which are important for the assessment of global climate change and natural hazards, must clarify the relationships between land uses, landforms, and regional geology. 相似文献
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Ioannis Gatsis reas Pavlopoulos & Isaak Parcharidis 《Geografiska Annaler: Series A, Physical Geography》2001,83(4):217-228
Natural hazards are mostly related to the activation of combined geomorphological and geological processes that control landform development. The study area is located in the NE part of Peloponnese (Corinthos prefecture). It is a typical agricultural area with intense relief, the result of active tectonics and important human intervention. This study demonstrates the benefits from the synergism of SAR data (ERS-2) and optical data (SPOT2-XS) in order to highlight the possible natural-hazardprone areas. These data give different and complementary information since the radar signal depends mostly on topography, surface roughness and soil moisture, whereas the visible/infrared channels provide spectral information mostly on vegetation and land use/cover. The application presented here was focused on the enhancement of the high erosion risk areas, the improvement of the terrain interpretation, the mapping and highlighting of the landform morphology, and a more accurate determination of the main factors that control the flooding risk of Corinthos town. 相似文献
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2014年8月3日16时30分,云南省昭通市鲁甸县发生6.5级地震,此次地震危害性较大。在快速收集震区地震烈度分布、地形状况、土地利用/覆盖现状、乡镇人口、居民点分布、房屋建筑物以及高分辨率遥感图像等信息的基础上,应用GIS空间分析和定量评估模型,对重灾区自然环境状况,受灾人口、房屋建筑物及道路交通等敏感受体影响,牛栏江沿岸次生地质灾害风险等级,坡耕地退耕及水土流失防治4个方面进行了快速评估,并针对震区人员救助、地质次生灾害防治以及灾后重建生态治理提出了科学的对策建议。 相似文献
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Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature 总被引:7,自引:3,他引:7
An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria–slope gradient, local convexity, and surface texture–are calculated from a square-grid digital elevation model (DEM). The sequence of programmed operations combines twofold-partitioned maps of the three variables converted to greyscale images, using the mean of each variable as the dividing threshold. To subdivide increasingly subtle topography, grid cells sloping at less than mean gradient of the input DEM are classified by designating mean values of successively lower-sloping subsets of the study area (nested means) as taxonomic thresholds, thereby increasing the number of output categories from the minimum 8 to 12 or 16. Program output is exemplified by 16 topographic types for the world at 1-km spatial resolution (SRTM30 data), the Japanese Islands at 270 m, and part of Hokkaido at 55 m. Because the procedure is unsupervised and reflects frequency distributions of the input variables rather than pre-set criteria, the resulting classes are undefined and must be calibrated empirically by subsequent analysis. Maps of the example classifications reflect physiographic regions, geological structure, and landform as well as slope materials and processes; fine-textured terrain categories tend to correlate with erosional topography or older surfaces, coarse-textured classes with areas of little dissection. In Japan the resulting classes approximate landform types mapped from airphoto analysis, while in the Americas they create map patterns resembling Hammond's terrain types or surface-form classes; SRTM30 output for the United States compares favorably with Fenneman's physical divisions. Experiments are suggested for further developing the method; the Arc/Info AML and the map of terrain classes for the world are available as online downloads. 相似文献