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根据调查资料,介绍了七台河市泥石流的分布规律及灾害特点,概述了泥石流的形成、发育规律及演变过程,分析了泥石流灾害的影响因素。提出了治理措施,为山坡地利用、水土保持和地质环境治理及灾害防治提供依据。 相似文献
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2016-07-19日清江水布垭水电站大坝上游的坝子沟发生泥石流灾害。通过测量、遥感解译、地质测绘、现场试验及勘探等方法,查明了坝子沟泥石流发育特征,计算了不同频率下泥石流洪峰流量及一次泥石流过程冲出固体总量等泥石流特征参数,评价了泥石流活动危险性,为泥石流沟工程治理提供地质依据。 相似文献
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肖家沟泥石流发育特征及危险性评价 总被引:1,自引:0,他引:1
5.12汶川地震引起崩塌、滑坡、不稳定边坡大量发育,形成的大量固体物质堆积于山坡及沟道中,形成了巨量泥石流物源[1],震后泥石流爆发的临界降雨量大大降低,其启动和运动方式发生明显改变。泥石流活跃期可能持续10~20 a,将是影响灾区恢复重建的最大地质灾害隐患,应高度重视[2]。本文介绍了肖家沟泥石流沟发育特征并对其进行危险性评价,计算出不同频率暴雨下的输沙量,为省道303线的灾后重建以及今后的治理工作提供依据。 相似文献
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在山区复杂的地质条件和地质环境下,往往受到泥石流地质灾害的破坏,严重威胁生态环境和山区人民的生命安全。本文针对泥石流地质灾害的防治工作,探讨如何运用生态修复手段将泥石流灾害防治体系与生态环境建设相融合,增强生态系统的恢复与防护能力,对泥石流灾害进行合理防治。 相似文献
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新疆乌恰县地质条件复杂,构造活动强烈,断层发育,泥石流灾害频发。研究该区域泥石流发育的控制因素,对类似地区泥石流灾害的早期调查和防治具有重要意义。选取乌恰县泥石流最为发育的恰克马克河、苏约克河及托云达里亚河流域作为研究区,通过遥感解译与野外调查相结合的方法,对泥石流的分布规律与特征进行了分析,并进一步研究了控制泥石流发育的主要因素。结果表明:①乌恰县大规模泥石流的发育主要受断层和玄武岩喷出界面控制;断层带和玄武岩喷出界面处的岩体软弱破碎,为泥石流提供物源,且破碎带被雨水切割以后形成沟谷,为泥石流的流通提供地形条件。②泥石流分布在距离断层或玄武岩喷出界面3.5 km的区域内,总体上距离二者越近,泥石流分布密度越高;92.5%的泥石流分布在距离0~2 km区域,其中0~0.5 km区域泥石流最为发育,密度达到0.4处/km~2;另外,大规模泥石流主要分布在距离断层或玄武岩喷出界面1.0 km以内区域,而小规模泥石流主要分布在2 km以内的区域。 相似文献
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依据地质灾害形成发育的地质环境背景条件、发育现状、发育程度,对巴彦县地质灾害区的不同灾种易发程度,按照区域进行了划分和研究。通过对巴彦县已发生的滑坡、泥石流、土壤侵蚀等地质灾害点进行调查,查明地质灾害隐患点的发育分布情况,通过定性定量的评价方法建立地质灾害分区防御体系,协助当地政府最大限度地减少地质灾害所造成的生命、财产和经济损失。 相似文献
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文章通过对某水电站工程区内泥石流发育状况、分布、泥石流的类型和活动趋势进行分析,找出了泥石流分布规律、泥石流发育的特征和影响因素,对后期泥石流治理和工程防护提供了地质依据。 相似文献
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根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。 相似文献
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The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects. 相似文献
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In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment. 相似文献
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V. K. Konovalov O. V. Yashkin V. V. Ermakov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(2):105-109
A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed
in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash
and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers
of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional
components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect
dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system,
configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants
of dry ash utilization and the advantages of producing of size-separated particles are considered.
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Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008). 相似文献
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Peter B. Bayley 《河流研究与利用》1991,6(2):75-86
The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed. 相似文献
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We tested the recolonization of the phytobenthic community in the tailwaters of Glen Canyon Dam following long- and short-term experimentally induced desiccation. The response of Cladophora glomerata, Oscillatoria spp., miscellaneous phytobenthos species and periphyton was studied over 18 weeks using three treatments: (1) undisturbed control cobbles from the submerged zone; (2) cobbles desiccated and replaced into the submerged zone; and (3) cobbles desiccated and replaced into the varial zone. Periphyton density and compositional response resulting from these treatments were also examined. Desiccation treatments were significantly different in biomass from controls throughout the study. The biomass of desiccated and replaced river cobbles averaged <30% of the controls for C. glomerata and periphyton during the 18-week recolonization period. In contrast, the biomass of the control Oscillatoria and miscellaneous phytobenthos species averaged only 3 and 50% of that in the desiccation treatments, respectively. Cladophora, the dominant alga, comprised 77% of the phytobenthic biomass. A significant positive relationship between discharge, Cladophora and periphyton biomass was present in all treatments, while there was a negative relationship with discharge for Oscillatoria and miscellaneous phytobenthos species. There was a significant inverse correlation, as well as a pattern of separate biomass dominance, between C. glomerata and Oscillatoria. Cladophora was the dominant phytobenthos species on cobbles below the baseflow and Oscillatoria was dominant on cobbles in the varial zone. In general, the Cladophora biomass decreased under intermittent drying conditions, while Oscillatoria declined under permanently wet conditions. Diatom composition was not significantly different between treatments; however, their density was lower on desiccated cobbles. Diatom density on desiccated cobbles in the submerged and varial zones averaged 69 and 42% of that of the controls, respectively. Recovery and maintenance of benthic resources are hindered by fluctuating flow regimes driven by electricity and irrigation requirements. Repeated desiccation of the phytobenthos has major effects on the bottom-up interactions in the Colorado River ecosystem. © 1998 John Wiley & Sons, Ltd. 相似文献