包浍河治理概况及浍河干流河道演变分析

包浍河初步治理是我省１９９１年后继怀洪新河续建以来又一较大规模河道治理工程，河道疏浚长度达８０．４ｃｍ，筑堤长度为１１５ｋｍ，两项总土方量达２２００万ｍ６３，本次治理后将明显提高该流域的防洪除涝能力，综合效益显著，文章就包浍河河道治理概况和治理前的河床演变进行简述，并对治理后河道演变进行分析预测，提出工程建议。     

永宁江河道整治工程裁弯取直技术探讨

永宁江裁弯取直工程使河长缩短8.923km，降低了上游水位，提高了河道的泄洪能力，增加了土地面积，工程效益明显，对裁弯道两岸保护，齿坎高程确定，裁弯道断面形式等问题进行探讨。     

对平原河道整治的几点思考

平原河道建设包括土方开挖、疏浚、砌石、桥梁、河岸绿化,以及常年整修等工程。所以,河道工程不是一次性建设,而是持续的,长期的工作。笔者从事河道规划、设计、施工和管理工作20多年,总结提出以下实践经验,供参考。     

中小河流河道治理及生态修复措施分析

北方地区大部分中小河流在中上游兴建水库后,对下游河道产生河道萎缩、干化、植被退化等影响,另外河道内存在违建、排污、非法挖采等乱象,河流生态遭受严重破坏。以太谷县为例,70年代大兴水利建设,修建水库。水库下游河道存在堵塞、萎缩、无尾、无序排倒、挖采等问题。文中探索采用河道疏浚连通、新型护岸等措施修复河流生态,实现河道生态环境的可持续发展,有效制止生态环境的持续恶化,平衡河流开发与保护,构建河流生态新格局。     

基于河道治理的城市河流生态修复

城市化是城市河流生态系统退化的重要驱动力,也是城市河流生态修复的限制性因素。在分析总结城市河流治理中存在的问题的基础上,阐述了河流生态修复的科学内涵、原则和目标,从岸线形态修复、河床断面恢复、水质改善与净化、生物栖息地重建、河道景观构造等方面提出修复城市河流受损生态系统的方法和改进措施,以期为今后城市河道治理提供技术支持。     

河流生态修复技术和实践

河流生态修复的理念逐渐被人们所认知,一些符合生态修复理念的规划设计方法在工程建设中被逐步采用。在水利部科技创新项目和地方政府的支持下,一些河流生态修复示范工程取得了很好的建设效果并发挥了良好的示范效应。文中结合几个案例,介绍近几年在河流生态修复技术和实践方面所取得的部分进展。     

对河道治理及生态修复的思考

随着人们对河道整治观念的提高,河道的治理已从单纯的以人类自身利益为主的河道整治转到对河流自身环境和水生态的保护与修复,以及从流域角度出发的河流管理上来,追求可持续利用的生态健康的河流,求得开发利用与保护河流生态系统之间的相对平衡。该文提出了对平原、山区、和城镇河道的治理原则,阐述对污染的控制及改善水体的办法。     

基于维持河流健康的城市河道生态修复研究

城市经济的快速发展和人口的增加直接对城市河流造成了剧烈影响,如人们在城市河道整治中采用截弯取直、硬化河底及护岸等措施,使得城市河流中原有的自然水生态系统逐步退化,河水污染、河道淤积现象日趋严重。通过对河流健康生命内涵的阐述,分析了当前城市河道整治现状,提出了城市河道形态及河床、河床护坡和水体、河堤的生态修复方法等。     

山区河流典型河段综合整治模型试验研究

通过对嘉陵江广元市区河段水文特性、河道地形、河相关系及河床演变规律的分析,结合广元市防洪现状及城市发展规划、美化景观、建设用地的要求,对塔山湾弯道开挖方案进行了探讨.并对裁弯取直和双河并存两个方案进行泥沙模型试验.试验表明两个方案均可降低工程上游广元城区洪水位,对该河段通航有一定改善,两方案互有优缺点,为山区河段城市综合防洪整治带来新的思路.     

河流健康诊断与生态修复

河流生态修复的总体目标是恢复河流健康，实现人与河流的和谐共存。从河流系统诸功能与河流健康之间的关系出发。分析了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。根据河流受损功能、受损程度及其可修复性。提出了不同阶段河流治理和生态修复的对策。目前采用的主要技术包括：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。河流生态修复是一个多目标、多变量、多层次、多约束条件的动态优化问题，需要因地制宜、全面考虑、科学决策。     

河北省河道生态恢复的探讨

由于人类对河流水文状态的过度干扰，原有的自然水生态系统逐步退化。目前，河北省河道生态方面主要存在河道断流，河流生态系统受损，河道沙化成为风沙源等问题，为了恢复河道生态，必须实施跨流域调水，加强河道生态环境的综合整治和充分利用污水资源。     

刘树坤访日报告:河流整治与生态修复(五)

在河流整治中,工程建设必然会对生态环境产生影响。为了缓和和减轻这种影响,世界上一些发达国家开展了河流生态修复工作。根据工程建设对环境影响的内容、程度不同,河流生态修复方法也多种多样。     

Desnagging to resnagging: new directions in river rehabilitation in southeastern Australia

Extensive desnagging (removal of large woody debris and living riparian vegetation) and associated river improvement works were conducted in rivers of southeastern Australia (Victoria and New South Wales) between at least 1886 and 1995. Swamp drainage, large woody debris removal and vegetation clearing were strongly supported by legislation, government funding and institutional arrangements in both states. As a result, large amounts of large woody debris were removed from rivers, regenerating indigenous vegetation was cleared from within designed alignment widths and, ironically, huge numbers of exotic trees, especially willows, were planted. The environmental impacts of desnagging have only been documented on a few impacted rivers but have included increased flow velocity, spatially extensive bed degradation, massive channel enlargement and loss of fish habitat. Recognition of the need for more integrated land and water management, and new research on the hydraulic, geomorphic, biogeographic and ecological significance of large woody debris and the values of indigenous riparian vegetation during the 1980s led to a major shift in river rehabilitation. We have drawn on our own and other published research to further develop a set of guidelines for the incorporation of large woody debris into river rehabilitation plans. Our guidelines extend those recently prepared for southeastern Australia and address site selection, where to place timber, the amount to be introduced, how to distribute it, techniques of introduction and woody debris sources. However, in the long term, riparian vegetation rehabilitation within the potential recruitment zone is essential to supply large woody debris. Given that our results demonstrate that very large woody debris makes a significant contribution to the total loading, it will be a very long time (>100 years) before natural recruitment can be recreated. Copyright © 2003 John Wiley & Sons, Ltd.     

River channel cutoff dynamics,Sacramento River,California, USA

We measured patterns of river channel migration and cutoff between 1904 and 1997 on a 160 km meandering alluvial reach of the Sacramento River by intersecting a sequential set of river channel centrelines mapped from a field survey and aerial photography. We identified approximate dates and locations of cutoffs and quantified cutoff dimensions. Twenty‐seven chute and 11 partial cutoffs occurred over this 93‐year time interval, with an average of one cutoff approximately every 2.5 years or 0.0029 cutoffs per kilometre per year. The average rate of lateral channel change was over the study period was 5.5 ± 0.6 m year^?1 (approximately 0.02 channel widths per year) due to progressive migration and cutoff combined. An average of 5% of the total channel length moved laterally via chute cutoff at a rate of 22.1 ± 3.3 m year^?1 versus 94% of channel length that moved via progressive migration at a rate of 4.7 ± 0.5 m year^?1. The remaining 1% of channel length migrated via partial cutoff at a rate of 13.0 ± 2.8 m year^?1. Although channel cutoff was less predominant mode of channel change than progressive migration in terms of channel length, an average of 20% of the total floodplain area change between successive centrelines was attributable to cutoffs. Peak cutoff frequency was concentrated temporally between 1964 and 1987 and was also spatially clustered in specific active sub‐reaches along the valley axis over the entire study period. We hypothesize that the probability of channel cutoff is a function of both channel geometry and discharge. Bends that experienced chute cutoff displayed an average sinuosity of 1.97 ± 0.1, an average radius of curvature of 2.1 ± 0.2 channel widths and an average entrance angle of 111 ± 7°, as opposed to average values for bends migrating progressively of 1.31 ± 0.01, 2.8 ± 0.1 and 66 ± 1°, respectively. The sinuosity of Sacramento River bends experiencing chute cutoff appears to have been consistently declining from 2.25 ± 0.35 channel widths in 1904 to 1.54 ± 0.23 channel widths in 1987. We hypothesize that this trend may be due in part to the influence of land‐use changes, such as the conversion of riparian forest to agriculture, on the ‘erodibility’ of bank and floodplain materials. For the post‐dam flow regime (1937 on), cutoff frequency was significantly correlated with an estimate of cumulative overbank flow. Copyright © 2010 John Wiley & Sons, Ltd.     

Habitat rehabilitation on the upper Mississippi River

Upper Mississippi River ecological integrity has been severely compromised by human activity during the last 50 years. In response to the continuing decline of natural resource values, two approaches for protecting and improving the Upper Mississippi River-floodplain ecosystem have been used. Habitat rehabilitation and enhancement projects are being constructed at 54 locations to provide site-specific rehabilitation. The projects are designed to counteract the adverse ecological effects of sedimentation through (1) flow introductions, (2) the isolation of backwaters; and (3) flow diversions and wave breaks. Channel maintenance projects are being re-evaluated in an attempt to construct or modify existing river training structures that are environmentally sympathetic. The latter approach works with the river's energy, whereas the former attempts to overcome riverine processes. Both approaches have significant limitations because they affect limited areas. A proposal is presented that restores some ecosystem integrity by re-establishing occasional low river stages that occurred before the implementation of the Upper Mississippi River Navigation System.     

龙潭河陂下段河道生态整治水力计算

生态水利是当前水利研究的重点之一,也是今后水利水电事业的发展目标和方向.以从化市龙潭河陂下段河道生态整治工程为例,对工程中的河床生态整治工程以及河岸边滩生态整治工程所涉及的水力计算的方法和过程进行了分析和研究,有效地解决了工程枯水期景观水深维持与营造优良生态景观和洪水期河道顺利行洪等两个主要问题,实现了人水和谐的生态整治目标,也可为相关河道治理工程以及今后的河道系统性生态治理提供参考依据.     

山东省海河流域河道生态问题及治理探析

山东省海河流域有徒骇河、马颊河等5条大型骨干河道和300余条中小河道,是国家重要的商品粮生产基地和能源化工基地,但却呈现着有河皆枯、有水皆污、生态失调的局面。在分析了流域河道生态问题的成因后,提出要用生态方法解决生态问题的理念,科学规划,采取强有力的工程措施恢复河道生态与环境。     

Resilience of riparian vegetation after restoration measures on River Inn

River restoration is widely applied, although its effects are poorly understood, and degraded habitats might be difficult to improve. Moreover, there is a lack of monitoring as well as few systematic comparisons of restoration methods. This study presents results of a 4‐year monitoring on River Inn (southern Germany) investigating restoration by gravel or sand addition or embankment removal. The results were compared with reference sites that represent the pre‐restoration conditions. At the landscape scale, we analysed vegetation types based on aerial photographs, whereas at a smaller scale, we undertook vegetation surveys and evaluated species composition, growth, and life form, as well as the proportion of the target vegetation. After 4 years, the data indicated a “negative resilience” of the vegetation back to the state prior to restoration. The structural analysis revealed an extensive spread of reed at expense of bare soil. Thus, the species composition largely regressed to the pre‐restoration conditions, and neither annuals nor other pioneer species showed a long‐term benefit of river restoration. There were differences among the three restoration treatments after 2 years, but no longer after 4 years. However, the river restoration had three positive outcomes: (a) There was a temporary benefit for pioneer vegetation that most likely replenished the seed bank of the respective species, (b) the valuable reed communities showed resilience, and (c) the measures allowed some practical learning as expected for adaptive restoration.