城市河流生态修复的环境价值及实现机制

探讨了城市河流环境价值的内涵、分类体系及常用度量方法,并以上海市长宁区的河流生态修复为案例,测算其环境价值,分析其投入产出。据此分析我国城市河流生态修复资金短缺的原因,探讨城市河流生态修复的环境价值实现机制。计算结果表明:(1)生态修复后的城市河流环境价值增值显著,本案例总计约为4.7亿元/年,相当于2007年长宁区GDP的1.22%,年均产出投入比为14.63;(2)城市河流生态修复的正外部经济效应显著,河流沿线居民和企业是最大的受益者;(3)政府进行河流两岸统一开发、水资源定价、税费征收与转移支付是城市河流生态修复环境价值的主要实现途径;(4)营造全社会参与河流保护氛围,并使公众理解城市河流环境价值,是价值实现的关键步骤。     

城市河流生态修复浅议

城市河流与城市的产生、发展息息相关，且是城市生态系统的重要组成部分，因此研究城市河流对于城市可持续发展及满足人们对于城市环境的需求变化具有重要意义。本文针对城市河流的现状，如直线化、平面化严重、水环境质量恶劣、生态系统功能丧失、水景观缺乏等，分析了造成城市河流当前问题的原因：一是城市化进程的影响；二是人类规划利用城市河流的理念不当。提出了城市河流生态修复应遵循的原则和指导思想，恢复河流生态功能的方法（多自然河流建设，生态技术的应用，创造适宜的生境，利用城市水文循环过程等）及城市河流景观建设的主要因素（合理的可见度、景观异质性、自然因子的有机融入、文化底蕴的挖掘等），并探讨了未来城市河道整治的发展方向。     

基于水生态文明建设的城市河流生态治理措施

文章基于水生态文明城市建设提出城市河流生态治理措施。对河道斜堤重新设计,为河流生态系统提供聚集地;采用先治理后修复的原则,对水质以及底泥治理实现河道修复,为河流生态系统提供栖息环境;使用水生植物吸附作用以及生态群落净化作用,实现河道生态系统的修复,完成城市河流生态治理。为保证设计治理措施的有效性,模拟环境进行仿真试验,试验结果表明,设计方法恢复了河流生态系统,为城市河流生态治理提供了有效的治理方案。     

试论河流生态修复规划的原则

在指明河流生态修复的目的、任务的基础上，提出了河流生态修复规划的五条原则，即河流生态修复与社会经济协调发展的原则；流域尺度规划原则；增强空间异质性的景观格局原则；以生态自我修复为主．人工适度干预为辅的原则；生态修复工程与资源、环境管理相结合的原则。     

论河流生态修复

本文以河流系统诸功能与河流健康之间的关系为主线，从人与河流关系的发展与变化出发，探讨了原始自然阶段、工程控制阶段、污染治理阶段和河流生态系统修复和改善等四个阶段的河流特点和治理条件，分析了各个阶段河流系统平衡的特征和影响因素，初步建立了河流健康诊断指标体系，提出了河流生态修复的主要原则。河流生态修复的总体目标是恢复河流系统健康，实现人与河流的和谐共存。河流生态修复主要技术包括：缓冲区修复、植被恢复、河道补水、生物-生态修复、生境修复、水生生物群落修复技术等。本文采用层次分析法的基本思想，探讨了河流健康、河流功能、功能要素和生态修复措施四个层次的关系，同时指出了实现河流生态修复的步骤。     

城市河流的渠道化园林化问题与自然化要求

计论了渠道化和园林化对于城市河流生态系统的危害，指出当前盛行的城市河流园林化是新一轮河流的人工化改造。提出了河流修复的自然化方法，即以水质条件恢复、水文条件恢复、河流案观格局改善和生物群落结构改善为目标的河流生态修复方法。还讨论了河流的美学价值，指出自然河流是具有高度生物群落多样性和景观异质性的开放地带，只有自然河流才能给人以审美欢愉，因此河流的美学价值核心是自然之美。河流的园林化不仅造成生态系统的胁迫，而且降低了河流的关学价值。     

基于城市河道生态治理措施研究

从水文化、景观、管理、安全以及水生态的角度探讨了城市河道水生态文明建设理念,在此基础上提出了堤坡设计、河道与生态系统修复的生态治理方案;为完成城市河道治理和实现生态系统修复引入生态群落净化与水生植物吸附作用,通过仿真模拟河道环境验证了设计方案的有效性。研究表明:拟定的生态治理设计方案能够恢复生态系统环境,可为城市河流治理提供一定参考依据。     

北京市中心城区水系空间生态功能修复思路研究

中心城区水系空间是城市空间和生态空间中的关键部位,是生态功能最集中、生态力最强的区域之一.城市水系空间生态修复可以对城市受损河湖生态系统进行重构,围绕城市和市民需求提升生态服务价值,恢复水生态系统生态过程.把北京市中心城区水系空间作为系统进行规划研究,针对不同河段的特性提出因地制宜的修复策略,引导城市、人与河流生态系统的和谐发展,提高城市河流生态修复规划的可落实性.     

河流生态修复成本效益分析研究

随着社会经济发展和科技进步,人们逐渐认识到维系河流健康生命的重要性,我国的河流生态修复正处于起步阶段.一些地区结合河流整治和城市水利建设,开展了河流生态修复示范工程建设.对河流生态修复成本效益分析十分必要.河流生态修复是一个渐进的过程,具有多种影响,其经济分析具有特殊性.全面的河流生态修复经济评价应考虑河流的生态环境价值.提出了河流生态修复的成本效益分析框架,将环境质量影响纳入经济决策中,进行了河流生态修复工程的成本和效益分类.     

人水共生视角下城市河流生态修复研究与实践

城市的形成和发展与河流水系密切相关。受城市蔓延与人口扩张影响,水质恶化、生态受损、生境退化等成为城市河流普遍存在的问题。结合人们对河流在安全、生态、景观等方面的需求,探讨了城市河流生态修复的策略与技术措施。以临汾涝洰河和兰州黄河沟道为例,探讨了弹性型和紧缩型河流的生态修复和景观营造策略。临汾涝洰河作为弹性型河流,重点聚焦河堤结构调整、河道平面形态重塑、河岸缓冲带修复及休闲活动空间营造。兰州黄河沟道作为紧缩型河流,在堤岸沿线及河道内部寻求机会,在保证行洪安全和堤坝稳固的前提下,结合海绵设施、生态浮岛等进行生态化改造及多级景观平台营造,以期实现人水共生的可持续发展。     

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.     

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.     

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。     

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.     

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。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.