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张彦宏 《水科学与工程技术》2003,(Z1)
在介绍全市地下水资源开采现状的基础上,全面分析了地下水超采区形成的主要原因及存在的问题,针对地下水超采区水资源开发利用中存在的问题,提出了地下水超采区水资源开发、节约、保护和利用的具体措施。 相似文献
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张彦宏 《河北水利水电技术》2003,(B09):34-36
在介绍全市地下水资源开采现状的基础上,全面分析了地下水超采区形成的主要原因及存在的问题,针对地下水超采区水资源开发利用中存在的问题,提出了地下水超采区水资源开发、节约、保护和利用的具体措施。 相似文献
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山西省属于水资源缺乏省份,在全省国民经济各部门取水量中,地下水取水比例占到一半左右。为有效保护全省地下水资源,在对山西省地下水资源及其开发利用状况进行分析的基础上,阐述了地下水超采区的分布及其主要特征,并提出了相应的防治和保护措施。 相似文献
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通过对江西省地下水资源开发利用现状的调查与研究,分析指出了其局部区域地下水超采、地下水污染等一些环境地质问题。根据水文地质条件、地下水开采潜力和地下水开发利用的需要等,对全省地下水功能区进行了划分。在此基础上,以地下水功能区为研究单元,根据功能区的地下水资源状况和生态环境保护要求,考虑未来地下水资源利用需求,为加强地下水的开采控制管理,确定各功能区的控制开采量,提出了江西省地下水资源开发利用方案。 相似文献
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山西省属于水资源缺乏的省份,在全省的取水量中,地下水比例占到60%以上。在一些严重的地区,地下水利用比例达到80%以上。过度开采地下水造成了潜在的灾难,带来巨大的经济损失。为有效保护全省地下水资源,结合山西省气象、水文、地质、水文地质、水资源及其开发利用状况进行分析的基础上,分析了全省地下水超采区的分布及其主要特征,并提出了相应的防治和保护措施。 相似文献
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通过对山东省1984~1993年系列及现状年1993年地下水开发利用状况分析,划分了地下水超采区,分析计算了全省及超采区多年平均地下水资源量及可开采量;在对全省2010年需水量预测及现状条件和规划条件下地下水可供水量预测的基础上,对全省及超来区地下水资源进行了开发利用规划研究;并通过供需平衡分析,提出实现全省地下水资源合理、有效、持续利用的对策与措施。 相似文献
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为对喀什噶尔河流域地下水资源进行合理开发利用和保护,基于现行的《全国地下水功能区划分技术大纲》内容,对流域内生态环境保护、地下水资源开发以及地下水系统特征等方面进行了全面分析,因水制宜地划分了各级功能区,同时密切结合流域内地下水超采问题对不同功能区分别提出了具体保护目标,对地下水保护和利用及超采区治理提供参考。 相似文献
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基于安徽省地下水资源禀赋条件、开发利用现状及存在问题分析,提出"加大宣传力度,厉行节约用水;完善地下水开发利用监管制度;落实超采区治理措施;加强地下水监测能力建设"的措施建议,为安徽省地下水水资源保护及开发利用提供参考。 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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简述天湖水电站投运以来各种故障的表现形式,分析其原因,提出了相应的处理方法及措施,并对合理利用国内外设备提出建议。 相似文献