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在地震地下流体动态研究中发现有多种干扰,特别是地下水资源开发的干扰较为普遍,地下热水开发的干扰较为严重,影响地下流体动态监测的效果,因此需要关注、调查与研究地下水开采对地下流体动态的影响问题。作者在研究京北地热田区水文地质条件及热水开采的历史与现状的基础上,重点分析了热水开采对不同水文地质条件与离开采井距离不等的观测井地下流体动态的影响及这种影响在不同测项上表现的差异。研究结果表明,在京北地热田区热水开采对地下流体动态的影响距离为5km,对位于导水断裂带附近的观测井动态影响最为明显;就测项而言,对水位与水温动态的影响最为明显,其次是逸出气(Rn,Hg)动态的影响,对土壤气(CO2)动态的影响不明显 相似文献
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台站资料在我国地磁学基础研究中的应用 总被引：3，自引：1，他引：3
台站观测资料包含了上至太阳活动、星际空间、磁层、电离层活动，下至地壳构造、地震活动、地球深部导电特征，乃至地核活动的各种丰富的信息。中国学者利用台站资料广泛开展地磁学的基础研究，在研制中国地磁场模型，研究地磁场长期变化规律、地下的导电率结构及震磁关系等方面取得了许多成果。文章介绍了台站资料在中国地磁学基础研究中的应用。 相似文献
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Because of its direct influence on the amount of unfrozen water and on the strength of intergranular ice in a frozen soil, temperature has a significant effect on all aspects of the mechanical behavior of the active layer in which temperature fluctuates above and below 0 °C. Hence seismic responses of engineering structures such as embankment on a sloping ground in permafrost regions exhibit obvious differences with seasonal alternation. To explore the distinctive seismic characteristics of a railway embankment on the sloping ground in permafrost regions, a coupled water-heat-dynamics model is built based on theories of heat transfer, soil moisture dynamics, frozen soil mechanics, soil dynamics, and so on. A well-monitored railway embankment on a sloping ground in Qinghai–Tibet Plateau is taken as an example to simulate seismic responses in four typical seasons in the 25th service year. The numerical results show that seismic acceleration, velocity and displacement responses are significantly different in four typical seasons, and the responses on October 15 are much higher among the four seasons. When the earthquake is over, there are still permanent differential deformations in the embankment and even severe damages on the left slope on October 15. Therefore, this position should be monitored closely and repaired timely to ensure safe operation. In addition, the numerical model and results may be a reference for maintenance, design and study on other embankments in permafrost regions. 相似文献
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Summary Authors' work of recent times on sedimentary petrophysics is reviewed. A report is given on theoretical work about petrophysical relations, based on a versatile model of the pore structure, using statistics and topology; on means for directly measuring pore structure by computerized image analysis of sections; and on an experimental study about an electrical interface conductivity of porous, water saturated rocks and its relations to structure. Some outlook on a subject of very recent interest: recovery of geothermal heat from porous formations, is added. 相似文献
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电法勘探在经历了近一个世纪的发展后，其方法理论、仪器设备、野外数据采集、处理和解释等方面都经历了一系列重大变化．本文以方法理论的进展为主线，回顾、展望了目前电法勘探中几个重要而令人关注的研究焦点．这些问题的研究进展将会对21世纪的电法勘探产生深远的影响． 相似文献
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Based on the precipitation data obtained through GEWEX Asian Monsoon Experiment–Tibet fieldwork from May to September 1998, this study investigated the features of the summer monsoon precipitation on the northern and southern slopes of the huge Tanggula Mountains in the Qinghai–Xizang (Tibetan) Plateau. The results show that the precipitation on the southern slope is about 50% higher than on the northern slope, whereas the frequency and diurnal pattern of the precipitation are very similar. The mean precipitation intensity on the southern slope is larger than on the northern slope. In most cases, the daily precipitation showed similar variation on both slopes, demonstrating that the precipitation processes might be similar. In the summer monsoon period, the local convective precipitation contributed to the total precipitation on both slopes and such a contribution on the southern slope is larger. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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This research focused on the determination of land cover thresholds that have a significant impact on runoff generation and soil loss at the pedon scale. For this purpose, six erosion micro-plots were set up on grassland and shrubland types of rangeland in the northeast of Iran, and the amounts of vegetation cover, litter, runoff and soil loss on them were measured. A factorial statistical analysis was carried out on the completely randomized design using land cover and rainfall factors. The results show that the effect of rainfall on soil loss and runoff was greater than that of land cover. Also, the effect of land cover on soil loss was greater than that on runoff generation. Furthermore, two specific thresholds were identified: the first was from 10 to 30% of landcover and the second from 50 to 70%. 相似文献
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地震科学的几个发展趋势 总被引：9，自引：3，他引：9
综合介绍了地震科学的几个发展趋势，包括：从板块理论向板块边界带研究的过渡，从深部结构研究向浅层地壳结构研究过渡，从观测向模拟研究过渡，从地震危害性向地震危害性研究的过渡。 相似文献
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Hydrogeomorphic processes and vegetation: disturbance,process histories,dependencies and interactions 总被引：1，自引：0，他引：1
Riparian vegetation and hydrogeomorphic processes are intimately connected parts of upland catchment and fan environments. Trees, shrubs and grasses and hydrogeomorphic processes interact and depend on each other in complex ways on the hillslopes, channels and cone‐shaped fans of torrential watersheds. While the presence and density of vegetation have a profound influence on hydrogeomorphic processes, the occurrence of the latter will also exert control on the presence, vitality, species, and age distribution of vegetation. This contribution aims at providing a review of foundational and more recent work on the dependencies and interactions between hydrogeomorphic processes and vegetation. In particular, we address the role of vegetation in the initiation of hydrogeomorphic processes and its impact on stream morphology as well as immediate and long‐term effects of hydrogeomorphic disturbance on vegetation. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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相邻地形对地震动特性的影响分析 总被引：1，自引：0，他引：1
基于采用透射人工边界的显式动力有限元方法,研究了相邻凸起地形对地震动反应谱特性的影响,分析了相邻凸起之间距离的变化对地形效应的影响。研究结果表明：1）与单一凸起地形对地震动的放大效应相比,相邻地形的存在对地震动反应谱谱比曲线的形状影响不大,但是却对谱比的值具有较大影响,而且其影响程度的大小与地表观测点的位置有关;2）相邻凸起地形的存在对凸起平台段中点地震动高频成分的放大效应具有较大影响,随着相邻凸起之间距离的增大,该影响效应逐渐减弱,多个相邻凸起构成的组合地形对地震动的放大效应逐渐接近单一凸起地形。 相似文献
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采用基于ABAQUS平台的显式有限元动力学分析方法,结合人工黏弹性边界理论,研究了局部凸起地形对地震动特性(包括反应谱、峰值加速度、峰值速度和峰值位移等)的影响,分析了台地宽度对地形放大效应的影响.结果表明:凸起地形平台段空间点地震动受地形效应影响较大,在零阻尼条件下,其谱比曲线呈双峰特点,.8—0.9s的中长周期段谱比达到一个较大值1.6,在0.08—0.09s的高频段谱比超过2.0,且最大值出现在平台中点;对于凸起地形斜坡段,在大部分周期点处,顶点的谱比高于其它斜坡点,而且在周期超过0.4s的频段,斜坡段观测点的谱比表现出较明显的规律性,即越靠近顶点的观测点,其谱比值越大;坡底段地表不同观测点的谱比基本在脚点与计算边界点(人工边界点)对应的谱比值之间变化,在不同的频段均表现出较明显的规律性.凸起地形平台段宽度对地震动高频成分的放大效应具有较大影响,但只局限在一定的宽度范围内,随着宽度的增大,其对地形放大效应的影响逐渐减弱. 此外,台地宽度的变化对地震动峰值加速度的放大效应有一定的影响,而对峰值速度、峰值位移的放大效应的影响则不明显. 相似文献
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A strong-motion accelerograph array in Santiago, Chile has been installed. One of the sites is located on rock and the other six sites are on soil ground with different surface geology, so that local site effects on ground motions can be studied. As a preliminary evaluation of the site effects, the spectral ratios of weak-motion records at soil sites with respect to the rock site are calculated. The spectral ratios show that the amplification of ground motions with respect to the rock site is approximately 1.25 on dense gravel deposits, 2.5 on stiff pumice ground and 3.5 on soft silt ground. 相似文献
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活动构造研究——历史、进展与建议 总被引：9，自引：3，他引：6
文中综述了国内外活动构造研究的历史与进展。在简要介绍国际以及中国早期活动构造研究历史的基础上,重点回顾了20世纪80年代以来活动构造及其定量研究的历史与发展,阐述了中国在活动构造基础调查研究、应用研究以及区域活动构造及其运动学、动力学理论研究等方面的主要工作与认识;进一步介绍了在活动构造定量参数测定方面的研究工作,以及基于这些定量参数进行的活动断裂潜在地震危险性与危害性评价工作与进展。最后,结合中国活动构造研究现状与存在的主要问题,提出今后宜重点加强工作的若干建议 相似文献
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型钢混凝土柱恢复力模型试验研究 总被引：11，自引：3，他引：8
开展了6个1/2比例的型钢混凝土(SRC)框架柱试件的低周反复加载试验.重点考虑轴压力系数和配箍特征值对型钢混凝土柱变形性能和滞回特征的影响.在试验研究基础上,分析了滞回曲线特征,并确定了恢复力模型的滞回规则.通过对试验结果的回归分析确定了卸载刚度和反复加载下的强度退化率,主要考虑参数包括位移延性比和轴压力系数.恢复力模型的骨架曲线由弹性段、强化段和强度退化段组成三线形骨架曲线.骨架曲线采用基于截面条带法和按实验数据的统计回归分析方法确定,其强化段和强度退化段均考虑了轴压力系数的影响.从而建立了能够考虑轴压力系数对滞回特性影响的型钢混凝土柱剪力-侧移恢复力模型. 相似文献
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Floods at the northern foothills of the Tatra Mountains — A Polish-Swiss research project 总被引：1，自引：1，他引：0
Zbigniew W. Kundzewicz Markus Stoffel Ryszard J. Kaczka Bartłomiej Wyżga Tadeusz Niedźwiedź Iwona Pińskwar Virginia Ruiz-Villanueva Ewa Łupikasza Barbara Czajka Juan Antonio Ballesteros-Canovas Łukasz Małarzewski Adam Choryński Karolina Janecka Paweł Mikuś 《Acta Geophysica》2014,62(3):620-641
The present paper introduces the topical area of the Polish-Swiss research project FLORIST (Flood risk on the northern foothills of the Tatra Mountains), informs on its objectives, and reports on initial results. The Tatra Mountains are the area of the highest precipitation in Poland and largely contribute to flood generation. The project is focused around four competence clusters: observation-based climatology, model-based climate change projections and impact assessment, dendrogeomorphology, and impact of large wood debris on fluvial processes. The knowledge generated in the FLORIST project is likely to have impact on understanding and interpretation of flood risk on the northern foothills of the Tatra Mountains, in the past, present, and future. It can help solving important practical problems related to flood risk reduction strategies and flood preparedness. 相似文献