基于能值的成都市水资源生态经济系统可持续性研究

基于能值理论,构建了成都市水资源生态经济系统可持续发展评价体系,评估了成都市2008年～2015年的经济发展状况、水资源开发利用状况以及系统的可持续发展状况。结果表明,成都市近年来的经济发展主要依赖于不可更新资源的消耗以及反馈输入能值的投入,可更新资源投入尤其是水资源投入的比重逐渐减小;水资源能值利用强度以及人均水资源能值用量逐年减小,与其经济发展水平不相匹配,系统的可持续发展水平较低。因此,成都市应积极调整产业结构,适当加大水资源等可更新资源的投入,以实现系统的可持续发展。     

黄河流域水资源-能源-粮食系统生态可持续发展能力评价

为综合评价黄河流域水资源-能源-粮食系统生态可持续发展能力，基于能值分析理论与方法，并结合熵值法，构建了黄河流域水资源-能源-粮食系统生态可持续发展能力评价指标体系，综合评价了该系统2008—2018年的生态可持续发展能力。结果表明：(1)从黄河流域整体视角来看，2008—2018年该系统属于资源消耗型经济发展模式，经济快速发展的同时对当地生态环境产生了很大压力，系统长期处于高环境负荷状态，造成系统生态可持续发展能力不断减弱。(2)从黄河流域各省(区)视角来看，流域下游生态环境压力日益加重，生态可持续发展能力较弱，应加大对可更新资源的开发力度，减小对不可更新资源的依赖；上游省(区)环境压力相对较小，生态可持续发展能力较强，应加强基础设施建设，促进经济发展。(3)黄河流域各省(区)水资源-能源-粮食系统均衡性在时间和空间上呈现明显的差异性，系统的生态可持续发展能力不断减弱。     

浅析黄河水资源的可持续管理战略

为实现“以黄河水资源的可持续利用,来保障黄河流域经济、社会、环境的可持续发展”,通过分析黄河水资源的特点与开发利用中面临的缺水形势严峻、部分地区用水浪费、水污染严重、中游干流河段水库调节能力不足、水资源管理水平亟待提高等主要问题,探讨了黄河流域可持续发展系统的特点及其该系统对黄河水资源可持续利用的主要影响、黄河水资源可持续利用指标体系的概念框架以及黄河水资源可持续利用的目标管理体系．     

黄河流域水资源承载能力影响因素分析

20世纪90年代以来,受自然条件和人类活动两个方面的影响,黄河多次断流,水资源短缺,水污染严重,水资源系统遭到了破坏,承载能力持续下降。这种情况已经严重影响到黄河中下游地区社会经济发展、生态环境的改善和人民生活水平的提高。通过对影响黄河水资源因素的分析,除了自然因素以外,管理因素、工程因素、技术因素、社会经济因素和宣传教育因素对提高黄河水资源承载能力和黄河流域社会经济的可持续发展具有重要的现实意义。     

基于属性细分的甘肃省水资源可持续利用评价

根据系统可持续发展属性细分理论,按水资源、社会、经济、生态、人口5个子系统确定70个指标,建立甘肃省水资源可持续利用评价指标体系,对区域水资源可持续利用状况进行了评价。结果表明:2005年甘肃省14个州、市水资源可持续利用态势值为0.337~0.487,均属弱不可持续状态。     

黄河近百年径流量变化分析与认识

黄河是中华民族的母亲河,其水资源的变化对黄河流域乃至全国的社会经济发展具有重要影响,缺水态势是黄河当前与未来的最大挑战。基于黄河干流兰州、头道拐、花园口和利津4个典型水文站1950—2017年近70 a的实测径流数据,分析了黄河干流年径流量变化特征。受气候变化和人类活动双重影响,黄河干流各水文站年径流量呈现显著的下降趋势,且下降速率呈现累积效应;20世纪60年代是百年来黄河径流量最大的时期,而90年代后径流量减少显著;4个水文站实测径流量在1985/1986年发生突变,变化期相较于基准期年径流量显著下降,且下降幅度从上游至下游递增。实测资料分析结果只反映黄河径流变化是气候变化与人类活动(含土地利用)共同影响的结果,如何区分它们的影响比例是尚待进一步研究的科学问题。美丽中国建设,黄河不可或缺。建议以促进流域水-生态-经济协同发展为目标,梳理黄河流域水-生态-经济可持续发展、水-能源-粮食之间的复杂关联,尽快提出黄河流域水资源利用、生态保护和经济协同发展方案。     

基于区域水资源承载力的引洮工程可行性论证

利用多目标优化软件,充分考虑水资源系统、经济社会系统、生态环境系统之间的相互协调与制约关系,以区域经济、社会可持续发展规划为依据,对2020年不同经济发展水平、不同生态目标组合的水资源承载能力进行了模拟评价,结果表明：实施引洮工程是解决该地区水资源短缺问题、实现区域经济社会与生态环境可持续发展的最佳途径。     

域水资源承载能力动态综合评价研究

该研究成果系统科学地分析了水资源系统、社会经济系统和生态环境系统三者之间的相互关系,构建了反映区域社会经济、生态环境和水资源可持续利用的水资源承载能力评价指标体系,并提出了相应的评价标准与等级。建立的水资源承载能力多目标动态综合评价模型具有上下两层复合结构,考虑了社会经济发展、生态环境保护和水资源合理利用,采用模糊优选模型对方案进行决策分析,从而确定符合经济和生态可持续发展的水资源承载能力指标值。水资源承载能力模糊动态综合评价模型采用灰色关联度法分析影响水资源承载能力的主要     

模糊优选熵权模型在水资源评价中的应用

应用模糊优选熵权模型对区域水资源系统可持续发展状况进行综合评价,计算简单、评价结果客观,且不同地域、不同年份间具有较好的可比性。以郑州市为例,根据2002-2005年水资源状况,以水资源条件、社会经济水平、水环境状况3个子系统为对象,进行水资源系统可持续发展评价,结果表明：郑州市水资源系统可持续发展水平从2002年到2004年持续提高,2005年略有下降;3个子系统呈非同步性、非一致性的特点。     

基于层次分析法的广西水资源可持续利用评价

水资源的可持续利用有利于保障生态、环境、经济和社会可持续发展。为研究广西水资源可持续利用发展水平,构建了4个准则层17个指标的水资源可持续利用评价指标体系,采用层次分析法的区域水资源可持续利用评价方法,对广西水资源进行可持续利用评价。评价结果表明:广西水资源可持续发展能力中等,为基本可持续水平,水资源利用效率权重偏小;为满足广西经济社会的可持续发展要求,建议提高水资源开发利用效率。     

地下厂房施工过程的三维非线性数值模拟分析

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。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

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.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

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.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

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. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

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.     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

Desiccation and recolonization of phytobenthos in a regulated desert river: Colorado River at Lees Ferry,Arizona, USA

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.