地表水地下水的交互与耦合模拟研究现状与进展

在介绍"四水"转化概念模型的基础上,引出了地表水与地下水之间的联系及相互作用过程,归纳地表水和地下水交互作用研究的基本规律和方法;系统介绍和对比国内外典型地表水与地下水耦合模型的总体结构、特点、适用领域及模型的局限性。对地表水地下水交互作用过程及耦合模拟研究中存在的问题提出看法,认为集成模型应该解决时空尺度整合、参数的不确定性等关键问题,指出综合水循环和水质各组成部分的复杂系统模拟是模型发展的必然趋势,对今后研究工作的发展趋势和研究前景作了探讨。     

基于文献计量的国际河流栖息地研究动态

河流栖息地是水域生态系统的重要组成部分,以Web of Science论文数据库为数据源,利用TDA等工具对2015-2017年国际河流栖息地研究进行文献计量分析。结果表明:该领域研究方向涉及环境科学与生态学、海洋与淡水生物学等多个学科;美国的发文量最高,中国居于第2位;"保护"、"河流"、"鱼类"和"气候变化"是热点关键词;当前河流栖息地研究动态集中于风险评估与生态修复、水生生物群落、外来生物入侵、栖息地的地貌变化等方面。     

新疆鄯善县水环境氢氧同位素特征及其指示作用

根据鄯善县氢氧稳定同位素资料及氘盈余（d）值,分析了地表与地下水体的δD、δ18O和d值的分布规律,并得到地下水的主要补给来源及其与地表水的相互作用关系;地下水的δD在-87.88‰～-65.97‰间,δ18O在-9.4‰～-12.37‰间;地表水的δ18O在-10.08‰～-13.63‰间,d在14.12‰～32.19‰间。结果表明：鄯善县地下水和地表水同源于大气降水,且经历了较强的蒸发作用;地下水与地表水之间的水力联系较弱,深层地下水主要接受河水在洪积扇区的入渗补给,浅层地下水主要接受河流引水灌溉入渗;不同深度地下水之间的水力联系较为密切,为统一的地下水系统。     

中国五大淡水湖研究态势：基于WOS的文献计量分析

中国五大淡水湖与区域国民经济发展关系紧密,在全国淡水湖泊中具有十分重要的地位和作用。基于Web of Science(WOS)中的SCI数据源,运用文献计量学的研究方法,对1989-2017年中国五大淡水湖研究的文献进行分析,从文献发表年代、国际合作研究、研究机构、期刊分布、核心作者、高被引文献、热点关键词等方面,揭示中国五大淡水湖的研究现状与发展态势。结果表明:近30年来,中国五大淡水湖研究态势较好,其中太湖研究的发文量增长最快,2006年就进入成熟期,是五大淡水湖研究中的热点湖泊,总被引频次超过200次的热点文献主要报道太湖研究;五大淡水湖研究文献主要集中在环境科学与生态学以及生物学领域的740种国际期刊上,中国科学院南京地理与湖泊研究所发文量占23%,在五大淡水湖研究领域占据优势地位且形成了相对集中的研究群;研究发文量在4篇及以上的核心作者共198名,占作者总量的9. 11%,国际合作文献占31. 9%,显示湖泊研究的开放和国际化程度;五大淡水湖热点研究领域主要在以沉积物、富营养化、水华、磷、氮、重金属等为热点关键词的湖泊环境与生态领域,以微囊藻、蓝藻、血吸虫、叶绿素等为热点关键词的湖泊生物研究领域,以水文水动力、江湖关系等为热点关键词的湖泊-流域相互作用与调控领域以及以遥感作为热点关键词的湖泊水环境遥感领域。     

基于文献计量的土壤污染研究趋势分析

为了解全球在土壤污染方面的研究趋势,以 2000—2019 年的Web of Science 数据库及其扩展数据库中有关土壤污染的科学论文为研究对象,借助文献计量学方法分析研究动态。结果表明:世界范围内相关发文量总体呈逐年上升趋势,美国和中国在该领域的发文数量领先于全球其他国家和地区,分别占发文总数的19.70%和18.93%;中国科学院系统发文量最多,浙江大学以1 598篇位居第5;华人研究者高被引的论文在世界范围内最多,前20名中占有11名,其中有3位来自于湖南大学;重金属成为土壤主要污染物,未来土壤修复热点将集中在植物修复、微生物修复、无机矿物修复和联合修复技术等方面。     

流域水资源管理研究论文计量分析

为了系统揭示流域水资源管理研究的现状、趋势和热点,以Web of Science数据库收录的关于流域水资源管理研究的论文为数据源,利用美国汤森路透公司的数据分析工具TDA,对全世界流域水资源管理研究的论文进行计量分析。结果表明:流域水资源管理研究的论文数量呈稳步增长态势,1991年以后的论文数量增加迅速;美国、中国、澳大利亚和欧洲国家的论文数量比较多,这些国家在此领域的研究比较活跃;2002年是国际流域水资源管理研究的转折年,之前的研究主题比较分散,之后的研究主题比较集中。     

基于水文要素过程的流域地下水与地表水交换径流成分定量分析

流域地表水-地下水相互作用中包括枯水季节深层地下水向河流稳定补给的基流,降雨入渗后形成的快速与慢速壤中流和洪水时期河道水位抬升引起的地表水补给地下水。目前对于地下水-地表水交换量的组成并没有清晰的定义,已有的水文实验和模拟方法不能准确辨析地下水-地表水交换组分。利用水文要素过程线,提出了综合新安江水文模型、改进马斯京根-康格(Muskingum-Cunge, MC)法和基流分割方法的技术框架,研究地下水-地表水交换量的组成情况,并以婺源江小流域出口断面为例进行了方法应用。研究结果表明：婺源江小流域的地下水-地表水交换量占出口断面总径流的43.54%～54.66%。饱和带中的浅层地下水占出口流量的8.41%～10.57%;降雨下渗进入浅层土壤补给河道的水流占6.81%～20.59%;深层地下水的稳定补给量占河道总径流的23.34%～26.54%。本研究提出了可以精细化辨析地下水-地表水交换分量的技术框架,结果可为类似流域水资源保护与管理提供理论依据。     

近十年间污泥预处理技术研究前沿及热点——基于WoS数据库的文献计量分析

污泥预处理对实现其减量化、无害化及资源化具有重要意义。为理清近十年国际上污泥预处理领域研究前沿与热点,以2010—2020年Web of Science收录的核心数据为研究对象,采用文献计量学方法,利用CiteSpace可视化工具,对领域发文量、国家、机构、期刊、作者和关键词等进行了分析。结果显示,近十年间污泥预处理受到学者们广泛关注,发文量呈指数形式上升,中国在该领域具有绝对的领先地位。污泥预处理研究主要发表在Bioresource Technology、Water Research等高水平期刊,具备较高的学术影响力。污泥预处理技术的研究多集中于在预处理技术对污泥消化性能影响、变化机理及其实际工程应用等方面,预处理方法的优化组合及工艺条件可能成为今后的研究热点方向。明确总结了污泥预处理的研究现状、发展历程和热点转变轨迹,为今后的研究提供参考和战略思路。     

禹城市主要水体硝态氮监测及变化分析

地表水硝态氮(NO3--N)污染与人类健康以及水体生态环境密切相关。以潘庄灌区的禹城市主要水体为例,采集研究区内10个点进行长期监测,主要监测项目包括pH值及NO3--N等水质指标。结果表明,2004年-2009年,禹城市不同水体pH值变化在6.8～8.8之间,符合地下水环境质量标准(GB3838-2002)基本限值。地下水pH值有下降趋势。不同水体pH值最低值多在7月,高值多在10月或1月。2004年-2009年禹城市主要水体硝态氮变化总体呈逐年下降趋势,地下水中硝态氮各年份间变化不大。各采样点灌溉用地表水和地下水中硝态氮含量大多在7月及10月增高,主要原因是小麦或玉米播种前施基肥后随灌溉淋溶进入水体,而受降雨量的影响不大。本研究为该区域水质安全评价提供科学依据。     

三工河流域氢氧同位素特征及其水循环意义

以新疆三工河流域为研究对象,通过对地表水、浅层地下水及深层地下水采样,分析δD、δ~(18)O及氘过量参数d的分布规律,得到地表水及地下水之间的转换关系。结果表明:山区降水是研究区内水体的主要补给源;降水向地表水转化过程中,受蒸发作用影响较弱;地表水在出山口入渗补给地下水过程中,经历了较强的蒸发作用,地表水入渗地下后,一部分转入深层地下水,一部分转入浅层地下水,地表水对地下水的补给贡献量所占的比例为78.0%;深层地下水与浅层地下水水力联系较密切,在平原区深层地下水逐渐向浅层地下水运移排泄;浅层地下水主要受地表水、灌溉水补给,少量受大气降水补给,受蒸发作用影响强烈。     

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。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

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。     

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。     

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.