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141.
This study focused on the landslide case at Su-Hua Highway 115.9k, Taiwan. A preliminary investigation was conducted on geomorphologic features change and landslide mechanisms using digital elevation models, geographical maps, and remote sensing images at different times in conjunction with geological surveys and analysis results. Using the results of geological surveys and physical model experiments, we constructed a discrete element method to simulate the process of landslide movement. The results revealed deformation in the metamorphic rock slopes upstream of 115.9k. The slopes around the erosion gully upstream presented visible slope toes cutting and tension cracks at the crest as well as unstable rock masses. According to the results of numerical simulation for typhoon Megi event, intense rains could induce slippage in the rock debris/masses in the source area, initially at a speed of 5–20 m/s. Subsequently, steeper terrain could cause the rock debris/masses to accelerate to form a high-speed (>30 m/s) debris slide quickly moving downstream to form an alluvial fan downstream by the sea. 相似文献
142.
Landslide spatial decision support systems (LS-DSS) are computer-based systems that combine the geographic storage, search, and retrieval capabilities of geographic information systems with the decision models and optimizing algorithms used to support decision-making for landslide problems. This study proposes an optimization process of region object-oriented classification (ROC) to analyze the landslide image information. The surface information from the Wan Da reservoir area is collected and studied. We collected different spectrum with several texture information to analyze the surrounding area of the Wan Da reservoir. ROC is used to classify the landslide area. Entropy-based classification is used as a classifier in ROC to determine the landslide/nonlandslide area. The parameters of S (similarity) and A (area) are used and then the best combinations are found. An optimize algorithm is developed to access the above variables to perform the best classification outcomes. The relations of occurrence vs. non-occurrence of landslide which are linked to the attributes of land surface are studied. An improved translation model (Expert Knowledge Translation Platform) is also presented to increase the accuracy. This could be of help to manage/monitor the landslide area near the reservoir. 相似文献
143.
中国煤中硒的环境地球化学 总被引:1,自引:0,他引:1
硒是煤中易挥发元素之一。伴随煤炭的开采、利用,煤中硒可能进入环境并引起环境质量的变化,影响生态环境和人体健康。本文在全面综合国内外研究文献的基础上,分析了中国煤中硒在不同省份、不同成煤时代中的含量及分布规律,总结了硒在煤中的赋存状态、形成机理和影响因素,概括了煤在燃烧和淋溶过程中硒的迁移转化及其环境影响,指出中国煤中硒的含量在不同煤田、不同成煤时代及不同变质程度的煤中,含量差别较大,全国平均值约为5.60 mg/kg。 相似文献
144.
印度季风与东亚夏季环流的遥相关关系 总被引:16,自引:6,他引:16
通过NCAR/NCEP再分析资料诊断发现印度夏季降水与东亚 5 0 0hPa位势高度有显著的相关性 ,形成了印度—东亚遥相关型 (IEA型 )。结合太平洋日本型 (PJ型 )的特征 ,指出PJ型主要决定夏季西北太平洋副热带高压的南北位置 ;IEA型在一定程度上影响副高脊西伸的东西经度或夏季中国大陆上空的平均位势高度距平。气候模式数值试验揭示出印度—东亚遥相关型对东亚很重要并且与印度洋海温异常有关 ,借此提出ENSO影响东亚夏季风的两条途径 :一条是直接路径 ,另一条为选择性路径。 相似文献
145.
1988至1990年,青海地区发生了4次震级大于6.0的强震。利用GDSN宽频带波形资料,通过波形模拟,结合地质构造的背景资料对这几次地震进行了震源破裂和发震构造背景的研究。使用台站的准震源时间函数和准时间差的分析方法,对震源和复杂性进行了讨论。 相似文献
146.
根据电法,人工地震勘探和钻孔资料分析了位于丹东东北部沿中朝边境长11km的鸭绿江断裂带分布特征。 相似文献
147.
对中尺度遥感资料进行四维同化的共轭方法及其数值研究 总被引:10,自引:4,他引:10
本文探讨了数值天气预报过程中对非定时观测的常规遥感气象资料进行四维同化,形成预报初始场的新途径,把数值预报初始场的形成提为数学上的一类反问题,运用数值模式及其共轭方程对象气资料进行变分同化的共轭方法,使众多观测资料的四维同化与时变的动力模型在初始场的形成过程中统一考察,克服了以往一些方法的局限性,从理论和数值角度证明该方法的可行性,表明该方法有可能作为发展一个新的初值方案的雏形,有潜在的应用价值。 相似文献
148.
149.
Some geophysical surveying works in the northeast part of Dandong, such as shallow shock refracted wave, electrical prospecting,
electrical sounding and wave velocity measuring, are introduced in this paper, and the dynamic parameters are calculated.
The results show that the basement structure in surveying region is very complex, the overburden thickness of the quaternary
period, velocity distribution and dynamic parameters are of regional characteristics. The depth of basement is deep in the
north and shallow in the west, the difference between north and west region is about 5–10 m. The south part of Yalu river
fault belt is composed of F1, F2, F3, F4, F5 fault, their strike direction is NE, we can determine that the F2 fault is the main one in Yalu river fault belt, and the south part of Yalu river fault belt has no activity since Holocene
Epoch.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 282–288, 1993. 相似文献
150.
A method, which uses metal compositions in lobster digestive glands as natural environmental tags, has been developed to trace lobster movements. Lobsters were collected from three selected sites, Minas Channel, Minas Basin, and Cobequid Bay, Inner Bay of Fundy, New Brunswick, Canada, that were known to be contaminated with Cu. Five metal variables (Ag, Cd, Cu, Mn and Zn) were processed for principal component analysis (PCA). Metal concentration and burden models were investigated and PCA was able to differentiate lobsters from the respective catch sites. The method was applied to investigate the May and June lobsters collected at the three sites to determine the migration rate during this period of the fishing season. The results show a high level of mixing at Minas Basin and Cobequid Bay in June, and lobster movement inward toward the inner reaches of the bay, with very limited movement outward from the inner bay. 相似文献