基于可变模糊集对立统一定理的水安全评价研究

为了与集对分析法得到的关于水安全评价的结果作比较,在目前研究的基础上,应用可变模糊集理论中的对立统一定理和水资源系统评价理论、模型与方法,研究了水安全综合评价问题,并列举了实例进行比较。综合评价结果表明,该方法理论严谨、概念清晰、计算简便,无论在理论上还是应用上都优于基于集对分析的水安全评价方法。     

基于广义对比加权的水安全综合指数评价

为了构建水安全综合评价模型,在分别提出"正向"和"逆向"指标安全指数公式基础上,采用广义模糊对比加权法对水安全评价体系的各个子系统进行赋权,得到水安全综合评价指数公式。应用该方法对山东省区域水资源进行安全评价,并与应用属性识别理论法和贝叶斯法对该例的评价结果相比较,结果一致,表明了该方法应用于区域水安全评价的可行性和实用性。     

基于边际效益递减原理的城市水安全评价方法

通过对城市水安全内涵的剖析和系统分析,将城市水安全系统分为支持子系统、协调子系统和防洪子系统,建立了逻辑清晰、层次分明的评价指标体系,并选用层次分析法确定了各层次指标的权重。在分析指标变化对城市水安全的影响规律的基础上,借鉴边际效益递减原理,建立了一种新的指标评价方法与模型。利用所确立的评价方法,对昆明城市水安全的现状及趋势进行了评价与预测,其得分为0.574,处于"不安全"状态,且有恶化趋势。该评价结果与实际基本相符,表明该方法体系有效、可靠,可用于城市水安全的评价研究。     

基于模糊集对分析法的新疆水资源安全评价

根据区域水资源现状,选取18个评价指标,建立了包括水资源、经济社会、生态环境、供需4个准则层的区域水安全评价指标体系;通过熵权法确定指标权重,采用基于模糊集对分析的水资源安全评价方法,对2016年新疆水资源安全状况进行了评价。结果表明:新疆水资源整体的安全状况属于基本安全等级,空间分布上北疆优于南疆和东疆;评价结果与物元分析法和综合指数法评价结果总体上一致,评价结果具有合理性。     

区域水安全研究浅议

本文对国内外研究现状回顾的基础上．提出了水安全主要研究的内容，包括水安全理论研究、水足迹研究、水安全评价和水安全模拟等。认为采用地理信息系统与数学模型集成研究的方法，是水安全研究的主要方法。     

基于对立统一与质量互变定理的水资源系统可变模糊评价新方法

根据可变模糊集理论导出的唯物辩证法对立统一与质量互变规律的数学定理--对立统一与质量互变定理,提出水资源系统新的可变模糊评价方法.文中以水资源可持续利用程度和水安全综合评价两个评价实例,说明了新方法的原理、模型与计算步骤.与模糊综合评判方法和集对分析评价法进行比较分析表明,该方法具有理论严谨、模型简洁和计算简便的优点,...     

双隐层BP神经网络模型在区域水安全评价中的应用

基于BP神经网络的基本原理和方法,构建双隐层BP神经网络水安全评价模型.以相关文献资料进行模型评价效果验证.验证表明:所建立的双隐层BP评价模型和评价方法是合理可行的,是一种可以运用的区域水安全评价方法.基于此模型,结合丰水地区区域实际,利用层次分析法构建了符合丰水地区水安全评价的指标体系和标准,以文山州区域水安全评价为例进行分析.结果表明:文山州各评价区域不同规划水平年水安全评价等级为Ⅳ～Ⅱ级,即处于不安全与安全之间,客观反映了文山州现状及中、长期水安全状况,符合区域实际,评价结果可作为研究区域水安全评价的参考依据.     

指标变换值表示的水安全评价的普适指数公式

适当设定水安全指标的参照值和指标值的变换式,并对各指标值进行了变换,使得以变换值表示的不同指标皆"等效"于一个规范指标,从而不同指标的水安全评价指数公式皆可以用该"等效"指标相应的指数公式替代。在满足设定的优化准则条件下,采用猴王免疫进化算法对公式进行优化,分别得到优化后对23项水安全指标皆适用的5个水安全评价的普适指数公式。对所获公式的可靠性进行理论分析以及对其实用性进行效果检验后,其评价结果与其他方法评价结果相一致,并与实际相符合。结果表明:水安全评价的多种形式的普适指数公式皆具有形式简洁、计算简便和普适通用的特点。     

水安全系统多变量迭代综合评价模型的应用

现有的水安全评价方法多为指标的加权和,忽略了指标间的相互作用对整个系统评价带来的影响。在证实水安全系统具有复杂适应性的基础上,基于复杂适应系统的4个特性和3个机制及其之间的相互关系,从各特性和机制协调度的角度出发,建立了水安全系统多变量迭代评价模型。该模型充分考虑了系统内部指标间的复杂非线性关系,评价结果更加科学、客观。对建三江地区水安全系统进行评价,结果与该地区实际情况相符,充分证实了该模型的可行性与有效性。     

基于"综合集成方法论"的水安全研究方法建构

水安全问题的复杂性决定了其研究方法的重要性。“综合集成方法论”是著名科学家钱学森在总结科学发展历程基础上，针对复杂问题所提出的重要研究思想与研究方法。在水安全研究方面．通过引入“综合集成思想”，从方法论层面对水安全这一复杂巨系统研究作出全面、透彻的分析，指出了水安全研究中存在的主要问题．提出了水安全研究综合集成方法，建立了水安全评价指标体系，以期对今后的水安全研究提供重要参考。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

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。     

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.     

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.     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

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。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。