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81.
Mohammad Ashtari Jafari 《Natural Hazards》2007,42(1):237-252
The Bayesian probability estimation seems to have efficiencies that make it suitable for calculating different parameters
of seismicity. Generally this method is able to combine prior information on seismicity while at the same time including statistical
uncertainty associated with the estimation of the parameters used to quantify seismicity, in addition to the probabilistic
uncertainties associated with the inherent randomness of earthquake occurrence. In this article a time-independent Bayesian
approach, which yields the probability that a certain cut-off magnitude will be exceeded at certain time intervals is examined
for the region of Alborz, Iran, in order to consider the following consequences for the city of Tehran. This area is located
within the Alpine-Himalayan active mountain belt. Many active faults affect the Alborz, most of which are parallel to the
range and accommodate the present day oblique convergence across it. Tehran, the capital of Iran, with millions of inhabitants
is located near the foothills of the southern Central Alborz. This region has been affected several times by historical and
recent earthquakes that confirm the importance of seismic hazard assessment through it. As the first step in this study an
updated earthquake catalog is compiled for the Alborz. Then, by assuming a Poisson distribution for the number of earthquakes
which occur at a certain time interval, the probabilistic earthquake occurrence is computed by the Bayesian approach. The
highest probabilities are found for zone AA and the lowest probabilities for zones KD and CA, meanwhile the overall probability
is high. 相似文献
82.
Bruno MOLINO Rosa VIPARELLI Annamaria DE VINCENZO 《国际泥沙研究》2007,22(4):273-281
Knowledge of the morphological dynamics of a water course is essential for management of reservoir siltation. With an example of sedimentation in a reservoir in Basilicata, Italy, this paper demonstrates the effect on reservoir siltation of the hydraulic works, which are aimed to reduce sediment transport along the fluvial network and to prevent part of the sediment discharge from reaching the lake. The effect depends on the river type and on the the geological features of river basin slopes. The paper also shows how mass erosion can significantly contribute to development of reservoir siltation. Finally, preliminary results are provided about the time needed for river training works to be effective. 相似文献
83.
84.
通过对非洲、澳大利亚、南美洲彼此之间的大陆架边界线相似的概率分析,指出巧合是不可能的,地球在过去几十亿年间一定发生了大规模的膨胀。 相似文献
85.
86.
重庆市滑坡、崩塌的发育规律及区域危险性程度区划 总被引:5,自引:0,他引:5
采用航空象片、遥感图像处理与野外实地考察相结合的综合研究,并根据前人的研究资料,详细解译了分布于重庆地区的各类滑坡、崩塌,总结了这些地质灾害的空间分布特征及发育规律,并对区域危险性程度进行了划分. 相似文献
87.
曲石湾滑坡体成因分析及防治措施研究 总被引:4,自引:1,他引:4
滑坡的形成对周围环境造成很大的影响,并严重制约地方经济发展,威胁人民生命财产安全,因此,滑坡成因及防治措施的研究具有重要意义。本文通过实际资料,分析曲石湾滑坡体的形成机理,有针对性的提出曲石湾滑坡的防治措施。 相似文献
88.
膨胀土是具有较大胀缩变形能力的特殊性粘土,膨胀土斜坡地区极易发生滑坡等地质灾害,本文根据安康汉江二号桥南侧滑坡勘察资料,较全面地介绍了该膨胀土滑坡特征,为滑坡根治提供了充分的地质依据。 相似文献
89.
Micro-sheeting of granite and its relationship with landsliding specifically after the heavy rainstorm in June 1999, Hiroshima Prefecture, Japan 总被引:1,自引:0,他引:1
M. Chigira 《Engineering Geology》2001,59(3-4):219-231
Certain types of granite in mountainous areas are microscopically sheeted to a depth of 50 m due to unloading under the stress field that reflects slope morphology. Micro-sheets generally strike parallel to major slope surfaces and gently dip downslope, forming cataclinal overdip slopes. The cataclinal overdip slope accelerates creep movement of micro-sheeted granite, which in turn loosens and disintegrates granite via the widening or neoformation of cracks, probably in combination with stress release, temperature change, and changes in water content near the ground surface. The surface portion of micro-sheeted granite is thus loosened with a well-defined basal front, which finally slides in response to heavy rain. Innumerable landslides of this type occurred in Hiroshima Prefecture, western Japan, following the heavy rainstorm of 29 June 1999. Following such landslides, the weathering of micro-sheeted granite exposed on the landslide scar recommences, setting the stage for future landslide. 相似文献
90.
Rainfall-induced landslides constitute a major public concern in Hong Kong. This paper investigates two aspects of critical importance to landslide hazard and risk assessment and management: magnitude–cumulative frequency relationship for landslides, and relationship between rainfall and the occurrence of landslides. The results indicated that landslides with a failure volume of not less than 4 m3 have a cumulative frequency–size distribution with a power-law dependence on volume of failure. Analysis of rainfall/landslides showed that the 12-hour rolling rainfall is most important in predicting the number of landslides. Failure volume dependency in the relationships between rainfall and the number of landslides is also presented. However, with an increase in failure volume of landslides, the most important rainfall variable may vary from rainfall of short duration (12-h rolling rainfall) to that of relatively long duration (24-h rolling rainfall). 相似文献