城市河流治理技术研究进展

城市河流水体具有生态系统复杂、污染类型齐全、污染源数量多、危害极为严重的特点。本文结合国内外最新研究成果和积累的宝贵经验，介绍了河道曝气技术、生态混凝土技术、阿科蔓复合生态技术、接触氧化技术、生态疏浚、化学强化一级处理、光催化技术等比较先进技术的研究进展，并对今后保护城市河流提出了建议。     

河流污染综合治理优化规划探讨

本文探讨了河流污染综合治理的概念,优化规划模型和程序,介绍了“节点开放试探法”的求解技术,并以四川省鉴溪河流综合治理为例,应用上述优化规划方法和求解技术。求出了综合治理最优解。结果表明优化规划方案比一般非劣解和未规划的方案可节省巨额污染控制费用。     

四川省河流生态环境需水量统计分析评估

本文介绍了标准流量法计算河流生态环境需水量的状况，针对四川省情况结合四川省水文资料，用当前广泛应用的各种标准流量法，对四川省河流生态环境需水量进行统计计算分析。其成果可以为有关部门和设计研究人员提供背景资料或决策依据。     

城市河流环境规划方案分析

河流流域的概念从20世纪30年代起开始被应用于环境规划管理中,相关的环境规划方法有很多。本文对城市中河流的环境规划从其原理、意义及各种具体措施等方面进行了论述,阐述了目前城市河流环境规划所具有的特点及面临的问题,对该规划的发展进行了展望。     

河流溢油模拟及规律研究

溢油发生在水中比发生在陆地的影响要大很多,并且发生在水中的漂移扩散更复杂。介绍了跨越管道发生溢油,并根据河流水期和泄漏点位置影响因素,设计了3个泄漏点分别在枯水期、平水期和汛期的9种不同情景,用MIKE 21软件对模拟河段进行模拟,得到了由不同水期和不同泄漏点位置组合成的情景下模拟结果,分析了不同水期和不同泄漏点位置的漂移扩散规律。     

中小河流的生存困局

河流是人类赖以生存的根基。溪水潺潺,小河淌水这是中小河流给人们的印象。然而,时过境迁,如今中小河流的命运正遭遇到前所未有的生存挑战。     

河长制背景下我国河流治理价值取向研究

河流治理问题不仅关乎国家经济问题,而且涉及人民根本利益,所以在面对严峻的河流问题,探寻其症结所在,探索河流治理价值取向则显得尤为重要。河长制作为新时代治理河流的治河政策,对于缓解我国河流治理困境以及对河流治理价值取向转向研究有着极其重要的作用。基于河长制的实施背景,从维护河流生态价值的角度出发,通过总结梳理河流治理体制现状,强调研究河流治理价值取向的重要性,通过对河流治理价值取向及其实现路径的理论的研究,辨析河流治理的价值取向,并从意识层面出发、从保障与监督机制以及立法协调角度对河流治理价值取向实现路径进行深入探索,得出其对维护河流生态功能、维持河流生态价值等具有重要意义,为河流管理发展规划提供参考。     

城市河流近自然治理--概念构架与治理设计

河流是城市生态系统的重要组成部分,是城市的自然元素和景观组分,具有提供水生生物生境和水源、调节小气候、美化城市、休闲娱乐等多种生态服务功能.随着城市化进程的飞速发展,城市河流生态系统面临着生物多样性减少、污染加剧等多方面的危害.如何恢复受损的城市河流生态系统已经成为我们的当务之急.对城市河流的生态结构及其在城市中的生态功能进行了简要介绍,讨论了河流生态恢复的近自然方法,并对现有的河流生态恢复存在的问题及发展趋势提出了几点看法.     

MFAM模型在河流水质污染模拟及预测中的应用

文中以时间序列分析为基础，介绍了均值生成函数这一崭新概念，并且经成份因子提取分析推导建立了模拟序列的数字模型（简记为MFAM），经对黄河下游花园口断面的1988-1989年实测水质污染指标溶解氧（DO），氨氧，化学耗氧量（COD），五日生化需氧量（BOD5）等序列模拟，结果表明MFAM模型能较好地模拟河流水质污染指标的变化趋势，拟合平均误差只有5.2-6.4%，MFAM模型应用于预测1990-1991年水质污染指标变化，结果表明预测精度达85%以上，文中最后得出结论：MFAM模型应用于河流污染模拟和预测，是完全可行且十分方便。     

市场化推进农村河流环境整治探究

农村河流环境污染的经济本质是由于环境“公共物品”属性导致其使用的外部环境不经济,本文把环境问题与经济研究接轨,设计了四种市场化利用模式,把河流厦相关公共物品“特定产权”明晰化,环保责任由政府承包转移到企业或个人,使责任明确化,从而有效对农村河流环境进行长效管理。最后以扬州市汉留镇河道清淤、保洁的市场化做实证分析。     

Modeling channel management impacts on river migration: a case study of Woodson bridge state recreation area,Sacramento river,California, USA

Understanding how hydraulic factors control alluvial river meander migration can help resource managers evaluate the long-term effects of floodplain management and bank stabilization measures. Using a numerical model based on the mechanics of flow and sediment transport in curved river channels, we predict 50 years of channel migration and suggest the planning and ecological implications of that migration for a 6.4-km reach (river miles 218–222) of the Sacramento River near the Woodson Bridge State Recreation Area, California, USA. Using four different channel management scenarios, our channel migration simulations suggest that: (1) channel stabilization alters the future channel planform locally and downstream from the stabilization; (2) rock revetment currently on the bank upstream from the Woodson Bridge recreation area causes more erosion of the channel bank at the recreation area than if the revetment were not present; (3) relocating the channel to the west and allowing subsequent unconstrained river migration relieves the erosion pressure in the Woodson Bridge area; (4) the subsequent migration reworks (erodes along one river bank and replaces new floodplain along the other) 26.5 ha of land; and (5) the river will rework between 8.5 and 48.5 ha of land in the study reach (over the course of 50 years), depending on the bank stabilization plan used. The reworking of floodplain lands is an important riparian ecosystem function that maintains habitat heterogeneity, an essential factor for the long-term survival of several threatened and endangered animal species in the Sacramento River area.     

Threats to beach resources and park boundaries caused by shoreline migration in an urban estuarine park

An evaluation of coastal processes, shoreline erosion, and shore management options for Conference House Park, New York, USA, reveals the problems associated with lack of congruence between jurisdictional boundaries and boundaries required for maintenance of beaches and shorefront park land. Rates of shoreline change are high despite low wave energies because bay beaches contain small amounts of sand. The park is so narrow in places that the shoreline will soon move out of park boundaries. This condition will eliminate natural beach resources, restrict access, and create political and administrative problems. Management strategies include revetment construction, beach nourishment, and acquisition of additional land. Obtaining the maximum length of shorefront to create a park may be less cost effective in maintaining natural beach resources than obtaining a shorter frontage and more compact shape that allows for shoreline movement. The problems of managing eroding shorelines in urban estuaries are acute because space is lacking, the cost of land is high, and the critical nature of shoreline erosion is disguised by low wave energies and lack of daily beach change.     

ARTICULATED CONCRETE BLOCK STABILITY TESTING1

ABSTRACT: An articulated concrete block revetment system was developed by the U.S. Army Corps of Engineers to test and evaluate the practicability of the protocols for overtopping and channelized flow conditions. Test facilities were constructed, prototype articulated concrete blocks were fabricated and installed into the facilities, and the blocks were tested using the established protocols. The test results indicated that both the overtopping and channel flow tests yielded similar results: the blocks reached a point of instability at approximately the same velocity and shear stresses. The similar test results indicate that only one protocol is required to evaluate an articulated concrete block system. It was demonstrated that both protocols can be effectively conducted. It is recommended that the overtopping test be adapted as a standard test procedure because of its reduced construction costs and its efficiency compared to the channelized test.     

A Geomorphic Explanation for a Meander Cutoff Following Channel Relocation of a Coarse-Bedded River

The Veteran's Fishing section of the Blackledge River in central Connecticut was relocated in the late 1950s. The relocation resulted in an unstable channel despite extensive efforts to prevent erosion. Overbank erosion and meander cutoffs were investigated using detailed survey data, characterizations of sediment deposits, flow modeling, and a moment-stability analysis. Limited reworking of revetment boulders indicate that riprap bank material was immobile during a 1979 flood event responsible for the formation of the cutoff channel. A moment-stability analysis factor-of-safety value of 1.1 supports the conclusion that riprap was not directly eroded from the banks. Alluvial particles with d₉₅ values ranging up to 120 mm were deposited along a bar downstream from the cutoff channel at flows estimated to be below a 1.5-year recurrence interval flow. Development of the bar deposit resulted in locally elevated water surfaces at high flow. The resulting overbank flow across the meander neck to the adjacent downstream bend led to the creation of an upstream migrating knickpoint, the erosion of approximately 16,000-year-old sediments, and the subsequent meander cutoff. The results of the study indicate that traditional erosion-control measures cannot prevent extreme channel adjustments if the geomorphic processes that control sediment continuity also are not considered.     

TEACHING WATER RESOURCES POLICY TO UNWERSITY SCIENCE AND ENGINEERING STUDENTS: OPPORTUNITIES AND CHALLENGES1

ABSTRACT: Effectively teaching water resources policy to university science and engineering students is both important and difficult. Most careers in the water resources field require an understanding of the comprehensive governmental regulatory structure affecting water use. Also, few science and engineering curricula encourage their students to take policy courses. Successful approaches to teaching water resources policy might include epistemological comparisons, case studies, issue maps, and interactive simulations. Obstacles to the effective teaching of this subject include students' insufficient preparation and student disdain and cynicism. These obstacles may be mitigated by requiring a prerequisite, developing a glossary of policy-related terms, and introducing the course through lectures emphasizing realistic views of the water resources management field and the nature of the American political system.     

Rockfall Hazard and Risk Assessment Along a Transportation Corridor in the Nera Valley,Central Italy

Rockfalls are a common type of fast-moving slope failures, and in many countries they represent the primary cause of landslide fatalities. We present a methodology to ascertain rockfall hazard and to determine the associated risk along transportation networks. The proposed methodology is based on the combined analysis of the recurrence of rockfall events, determined from historical information, the frequency-volume statistics of rockfalls, obtained from inventories of recent rockfall triggering events, and the results of a physically based, spatially distributed rockfall simulation model used to determine rockfall hazard. The available information on rockfall hazard is combined in a Geographic Information System with a map of the transportation network to identify the road sections potentially subject to rockfalls. Information on the location and type of rockfall defensive measures, including revetment nets, elastic fences, concrete walls, and artificial tunnels, is used to estimate the efficacy of the defensive structures and to determine the level of the residual rockfall risk along the roads. To illustrate the methodology, we discuss an application in a 48-km² area in the Nera River valley, in the Umbria Region of central Italy, where rockfalls are abundant, and where considerable investments were recently made to mitigate rockfall risk. Note: This version was published online in June 2005 with the cover date of August 2004.     

浅论装备可靠性工程

本文在介绍装备可靠性工程的发展历程和装备可靠性工程概念内涵的基础上,阐述了装备可靠性要求的确定、可靠性设计与分析、可靠性试验与评估和可靠性管理等工作内容,最后探讨了开展装备可靠性工程的要求和方法,以期给出装备可靠性工程的概貌.     

稻田稻麦两熟养鱼生态结构及功能研究

田间试验表明，深沟窄畦结构扩大了稻田生物的生境容量，畦麦沟鱼、稻鱼共生结构提高了稻田生产力，稻麦年产量稳定达到10．84～11.83t／ha，鱼产量3.11～4.20t／ha，在稻田产出中鱼占有最大产值优势度，系统能流结构表现出新特点，生态效率高。     

Genetic Engineering and the Integrity of Animals

Genetic engineering evokes a number of objections that are not directed at the negative effects the technique might have on the health and welfare of the modified animals. The concept of animal integrity is often invoked to articulate these kind of objections. Moreover, in reaction to the advent of genetic engineering, the concept has been extended from the level of the individual animal to the level of the genome and of the species. However, the concept of animal integrity was not developed in the context of genetic engineering. Given this external origin, the aim of this paper is to critically examine the assumption that the concept of integrity, including its extensions to the level of the genome and the species, is suitable to articulate and justify moral objections more specifically directed at the genetic engineering of animals.     

达县百节"水保生态园区"水土流失治理与生态环境保护

本文反映了严重的水土流失是导致达县百节河小流域生态环境恶化的主要原因。阐述了通过实施水土流失治理三大措施：工程措施、生物措施、农耕措施，有效地控制了水土流失等生态问题，极大地改善了当地生态环境，取得了显著的三大效益：经济效益、生态效益和社会效益。同时陈述了百节河小流域生态园区的建设特色：组织协调部门资金捆绑使用，集中投入：业主参与，责、权、利统一，投资渠道多元化，为水土保持和生态环境建设注入了生机与活力。