“Good Dredging Practices”: The Place of Traditional Eco-livelihood Knowledge

Residents of most rural communities in developing countries depend on surface water resources for their livelihoods. The development and management of this vital resource should as much as possible take into consideration local socio-economic priorities if sustainable development is to be achieved at local levels in these countries. Inland river dredging is a water resource management strategy usually aimed at improving water courses for navigation, land reclamation and or mitigate flood in the dredged catchment. Dredging operations like most development projects have impacts that are often localised, and benefits that could be local, regional or national. “Good dredging practices”, GDP, in industrialised countries have been aimed at balancing national/regional economic benefits, technical feasibility and environmental protection. These practices rely heavily on the quality, and quantity of available relevant base-line data. In most developing countries there is a dearth of baseline data, and often national/regional economic gains do not necessarily translate into local livelihood benefits. Hence, the basis of GDP should be extended to incorporate local livelihoods priorities, without ignoring the relevance of scientific data when it is available, the issue of technical feasibility, environmental sustainability and economic viability. This approach is relevant to the demand for equitable development in the developing world; could be used in conjunction with traditional eco-livelihoods knowledge in developing or determining appropriate approaches for sustainable surface water resources management, as well as reducing environmental conflicts between stakeholders.     

五里湖水污染治理现状及继续治理对策

污染严重的五里湖通过控制外源、生态清淤、调水、生态修复、退渔还湖、水域封闭管理、建设生态护岸和滨水区等措施,水环境明显好转。西五里湖1 km2生态修复区的水质原来为劣Ⅴ类,大部分指标改善至Ⅲ~Ⅳ类。今后继续治理对策:全部削减入湖小河道污染负荷;调贡湖水入五里湖;禁止货运,清洁航行,控制航行污染;全面生态恢复;全封闭管理。2010年水质改善到Ⅳ类,达到功能区目标。     

Drivers of revitalization in Great Lakes coastal communities

Sediment remediation and habitat restoration projects have been increasingly employed along the coast of the Great Lakes to improve environmental quality since the designation of 43 highly degraded Areas of Concern (AOCs) by the 1987 Great Lakes Water Quality Agreement between the U.S. and Canada. Improvements in water quality, habitat, and other environmental conditions can also support community wellbeing and revitalization; however, the mechanisms that support these connections are relatively unclear. We address this gap through a case study of three AOCs near Lake Michigan: 1) Grand Calumet River; 2) White Lake, and 3) Muskegon Lake. By analyzing secondary data and planning documents, we found that alongside environmental cleanup, anchor institutions, housing and economic development, and local events drive revitalization. Our research also illustrates that, rather than acting as discrete processes, environmental cleanup and revitalization drivers overlap in time and space. Finally, our research reveals a high level of variation within and across AOCs in terms of diverse socioeconomic contexts, planning capacities, and existing partnerships. Together, our findings point to the need for collaborative and inclusive planning processes that account for the heterogeneity present within and across AOCs to simultaneously support remediation, restoration, and revitalization and to sustain continued revitalization in AOC communities after delisting.     

Setting an agenda to catalyze research in the social and organizational dimensions of Great Lakes remediation,restoration, and revitalization

The Great Lakes region was once a hub of industry and innovation that provided wealth and identity to the region. Economic upheavals have left the region trying to recreate economies and cleanup degraded environments. There have been multiple, overlapping efforts to change these conditions and create a new narrative for the region through environmental remediation, habitat restoration, and community revitalization on the path towards resilience. The elements that contribute to success are organized differently in different places, and are not always identified or characterized in the environmental literature. Trying to fill this conceptual gap is critical because landscape-scale environmental cleanup has been delivered at the local scale through various partnerships and arrangements. Thus, this special collection of articles in the Journal of Great Lakes Research explores how individuals, organizations, and communities are engaging in the complex process of environmental cleanup and revitalization throughout the region. This collection of articles represents a range of approaches to unpack how people are navigating and contributing to this regenerative process from quantitative studies at the regional scale that characterize global patterns to in-depth qualitative studies that identify and characterize the processes that unfold in specific places to change our environments both ecologically and socially. These articles represent the broad experience unfolding in the region to understand these activities through research and navigate them through practice. This collection will add new dimensions to Great Lakes research by including the individuals, organizations, and agencies as components of the ecosystem.     

Transport of contaminants along the seattle waterfront: Effects of vessel traffic and waterfront construction activities

Cleanup of contaminated sediments along the Seattle waterfront is complicated by uncertainty regarding sources of contamination and the interrelationship between point sources, non-point sources, vessel traffic, construction projects, and resuspension. The results of field studies are presented that address the potential for recontamination of sediments following proposed cleanup projects, the sources of contamination and their relative magnitudes, and the natural and anthropogenic processes that affect transport of contaminated sediments along the waterfront. The primary factors affecting the success of cleanup projects along the Seattle waterfront are identified as resuspension of contaminated sediments by propellor wash and construction activities, and subsequent transport of the suspended sediments by natural and vessel-induced currents to adjacent areas.     

Goals,beneficiaries, and indicators of waterfront revitalization in Great Lakes Areas of Concern and coastal communities

Cleanup of Great Lakes Areas of Concern (AOCs) restores environmental benefits to waterfront communities and is an essential condition for revitalization. We define waterfront revitalization as policies or actions in terrestrial waterfront or adjacent aquatic areas that promote improvements in human socioeconomic well-being while protecting or improving the natural capital (the stocks of natural assets, biodiversity) that underlies all environmental, social, and economic benefits. Except for economic measures such as development investments, visitation rates, or commercial activity, evidence of waterfront revitalization in the Great Lakes is mostly anecdotal. We offer a perspective on waterfront revitalization that links indicators and metrics of sustainable revitalization to community goals and human beneficiaries. We compiled environmental, social, economic, and governance indicators and metrics of revitalization, many of which are based on or inspired by Great Lakes AOC case studies and community revitilization or sustainability plans. We highlight the role of indicators in avoiding unintended consequences of revitalization including environmental degradation and social inequity. Revitalization indicators can be used in planning for comparing alternative designs, and to track restoration progress. The relevancy of specific indicators and metrics will always depend on the local context.     

我国鱼类洄游通道和生境恢复技术研究现状分析

我国目前处于水电开发建设的高峰时期,生态环境保护问题受到高度重视。人们对河流资源的开发利用阻隔了鱼类自由迁徙的洄游通道,大大影响了鱼类赖以生存的环境,亟需发展洄游通道和鱼类生境的恢复技术来加以保护。阐述了鱼类洄游通道和生境恢复的重要意义,总结了该类技术在我国的研究现状和发展过程,指出了我国鱼类洄游通道技术发展面临的主要问题和挑战。通过对21世纪以来(特别是最近5 a)国家自然科学基金资助的相关项目及研究成果分析,指明了目前我国鱼类洄游通道和生境恢复技术的主要努力方向,包括:①各种典型鱼类的生活习性和游泳行为能力;②鱼类种群分布及生境因子影响规律;③水电开发对鱼类生境因子的影响规律;④洄游通道和生存环境恢复措施及过鱼效果验证。     

水岸生态治理中污泥处理再利用方案探析

目前,国内河道清淤疏浚中只对污泥进行提取或简单脱水等析出处理,污泥的后续利用没有得到很好的解决而造成浪费或二次环境污染。根据此状况提出的污泥循环处理工艺可以解决污泥的污染,同时可以达到污泥再利用的循环经济效应,整个设备的系统性模块化设计可以灵活应用于不同工况的水岸生态修复与保护工程。     

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。     

Human well-being and natural capital indicators for Great Lakes waterfront revitalization

Revitalization of natural capital amenities at the Great Lakes waterfront can result from sediment remediation, habitat restoration, climate resilience projects, brownfield reuse, economic redevelopment and other efforts. Practical indicators are needed to assess the cultural, health, and socioeconomic benefits of these investments. We compiled U.S. census-tract scale data for five Great Lakes communities: Duluth/Superior, Green Bay, Milwaukee, Chicago, and Cleveland. We downloaded data from the US Census Bureau, Centers for Disease Control and Prevention, Environmental Protection Agency, National Oceanic and Atmospheric Administration, and non-governmental organizations. We compiled a final set of 19 human well-being (HWB) metrics and 26 metrics representing attributes of natural and seminatural amenities (natural capital). We rated the reliability of metrics according to their consistency of correlations with metrics of the other type (HWB vs. natural capital) at the census-tract scale, how often they were correlated in the expected direction, strength of correlations, and other attributes. Among the highest rated HWB indicators were measures of mean health, mental health, home ownership, home value, life success, and educational attainment. Highest rated natural capital metrics included tree cover and impervious surface metrics, walkability, density of recreational amenities, and shoreline type. Two sociodemographic covariates, household income and population density, had a strong influence on the strength of associations between HWB and natural capital and must be included in any assessment of change in HWB benefits at the waterfront. Our findings are a starting point for applying already available HWB and natural capital indicators in a waterfront revitalization context.     

走马塘拓浚工程的生态效应

根据走马塘拓浚工程实施前后的地形变化,建立拓浚河道平面二维水动力数学模型,模拟河道拓浚前后走马塘典型河段的水动力变化情况,并分析拓浚工程对河道水动力特征的影响和拓浚工程的水生态效应。结果表明,拓浚工程的实施使得区域流速及断面横向流速分布变得均匀,对水环境改善有一定的正效应;河道拓浚工程的实施,短期内有利于浮游植物生长,但对浮游动物的生长有一定抑制作用,而从长期影响结果趋势来看,拓浚工程有利于水生生境系统的恢复与重建;河道拓浚工程的实施有利于底泥质量的改善,减少底泥污染物的含量,减少河道内源释放,对水质改善有正面效应;拓浚工程对底栖生物生境具有严重影响,但是随着时间的推移,底栖生境将会重建。     

Restoring relationships: Water heritage,sense of place,and community engagement

Widespread deindustrialization has changed the landscape and the character of many Michigan communities. In response to these often devastating changes, natural resources agencies have invested in restoration projects along Michigan waterfronts to facilitate a shift from an industrial past to new recreation and tourism development. The process of restoration and community rejuvenation is possible because, and depends upon, residents’ deep, often historical, connections with the water, which are in turn rooted in the ways water has been used, enjoyed, and stewarded in their communities, their water heritage. Understanding these nested relationships and the ways residents value the resource is an important component of effective restoration efforts. But conversations about values in natural resources decision-making intended to inform action require a mechanism for values prioritization and an environment of trust. We conducted two community engaged Office of Great Lakes (OGL)-funded studies that focus on Michigan residents’ care for and about the water resources. Both studies used a values ranking activity, a mixed methods approach to studying subjective viewpoints that provides insight into values priorities. In this paper we share the outcomes of both studies to illuminate how values ranking activities can foster stakeholder engagement, facilitate concrete discussions about restoration and natural resources values, and identify patterns in community attitudes about conservation. The analyses provide valuable insight into community dynamics and the potential for restoration success, as well as illuminate the role of sense of place in understanding individual and community values related to water resources.     

A Synthesis of Stream Restoration Efforts in Florida (USA)

Studies summarizing stream restoration projects in the US are outdated and omit the majority of restoration projects in Florida. To address this gap, we compiled stream restoration data from diverse sources to create a Florida Stream Restoration Database (FSRD, available at http://www.watershedecology.org/databases.html ) containing information on project type, location, completion date, and costs. The FSRD contains 178 projects categorized by restoration type, including riparian management (23%), stream reclamation (19%), flow modification (13%), bank stabilization (12%), channel reconfiguration (11%), in‐stream habitat improvements (11%), floodplain reconnection (6%), invasive species removal (4%), and dam removal (1%). Projects were spatially clustered into three geographic regions, providing insight on the diversity of initiatives, needs, and funding sources of land management agencies and private landowners that motivated restoration efforts. Projects in the Florida panhandle emphasized in‐stream habitat restoration, while peninsular projects were dominated by flow modification, and projects in the west central region focused on stream reclamation to mitigate surface mining practices and water quality and habitat improvements in tidal streams. Results suggest that Florida is spending much more on stream restoration than previously documented. Between 1979 and 2015, the mean and median stream restoration project costs in Florida were $15.4 million and $180 000, respectively, indicating a strongly skewed distribution because of the large Kissimmee River restoration project in central Florida. This work highlights the need for, and utility of, statewide and national restoration databases to improve restoration tracking. This need will become increasingly critical as more stringent water quality and habitat mitigation rules are implemented across the country. Copyright © 2016 John Wiley & Sons, Ltd.     

黄河上游连续弯曲多滩险河道整治方案数值分析

天然河道一般不能满足航运的实际要求,需进行航道整治。目前我国内河航道整治技术较为成熟,但对存在连续弯曲多滩险河道的研究较少。黄河上游白银市常生码头下游滩河道属连续弯曲河道,存在多处滩险,水流条件复杂,严重影响船舶的通航安全。以数值模拟为研究手段,构建二维数学模型,分析河道碍航因素,论证整治方案的合理性。确定采用填槽、切咀、疏浚和修筑潜坝等整治方法。整治效果明显,水力因素均达到通航指标,水流条件明显改善,为今后黄河上游及类似碍航特性的航道整治工程提供参考。     

金沙江石鼓宜宾河段梯级开发初探

金沙江流域具有丰富的水资源、水力资源、矿交资源。其中石鼓宜宾河段梯级开发是全流域综合利用开发的重点,河段内具有修建高坝的地形地质条件,淹没损失少,技术经济指标优越,开发条件较好。采用９级开发方案可以取得发电、航运及漂木、工农业供水、防洪方面的综合效益,并且是“西电东送”的主要水电基地,对三峡工程的发电、防洪拦沙也具有一定的作用,是长江上游继三峡工程之后的重点开发河段。     

Population effect of a large‐scale stream restoration effort on Chinook salmon in the Pahsimeroi River,Idaho

Stream habitat restoration is an important tool for fisheries management in impaired lotic systems. Although small‐scale benefits of stream habitat restoration are commonly investigated, it is difficult to demonstrate population effects. The Pahsimeroi River Chinook salmon Oncorhynchus tshawytscha population was previously restricted to the lower portion of the river by multiple irrigation structures. To address fish passage issues, a combination of restoration projects was initiated including barrier removals, instream flow enhancements and installation of fish screens on diversions. The largest barrier was removed in 2009, more than doubling the amount of accessible linear habitat. We hypothesized restoration efforts would expand the distribution of spawning salmon in the Pahsimeroi River watershed, leading to a broader distribution of juveniles. We also hypothesized a broader juvenile distribution would have population effects by reducing the prevalence of density‐dependent growth and survival. Redds were documented in newly accessible habitat immediately following barrier removal and accounted for a median of 42% of all redds in the Pahsimeroi River watershed during 2009–2015. Snorkel surveys also documented juvenile rearing in newly accessible habitat. Juvenile productivity increased from a median of 64 smolts/female spawner for brood years 2002–2008 to 99 smolts/female spawner for brood years 2009–2014. Overall, results suggested increased habitat accessibility in the Pahsimeroi River broadened the distribution of spawning adult and rearing juvenile salmon and reduced the effects of density‐dependent survival. Large‐scale stream restoration efforts can have a population effect. Despite the large‐scale effort and response, habitat restoration alone is likely not sufficient to restore this population.     

Aquatic vegetation responses to island construction (habitat restoration) in a large floodplain river

The Upper Mississippi River is maintained in its current navigable state through impoundments, dredging, and other engineering projects. These stressors, along with anthropogenic impacts and natural system processes, led to declines in aquatic vegetation and the loss of fish and wildlife habitat, with a major downturn the late 1980s and early 1990s. Large‐scale restoration projects, such as the one evaluated here, are primarily designed to rehabilitate and enhance fish and wildlife habitat. We determined whether an individual restoration project, construction of an island complex, fulfilled a programmatic goal of re‐establishing diverse and abundant native aquatic vegetation. Eighteen years of aquatic vegetation monitoring data from impact and reference areas were compared to evaluate the anticipated direct effects (within 400 m of the constructed islands) and indirect effects (>400 m downstream of constructed islands) of restoration. Impact areas were also compared with an unrestored negative reference area ~200 km downstream of the project and with a positive reference area in adjacent, relatively natural backwaters. Only indirect effects of restoration were evident. Prevalence and species richness of aquatic vegetation in both of the impact areas and in the negative reference area increased prior to restoration, suggesting large‐scale improvement independent of the project examined here. Indirect effects were demonstrated as further increases in both prevalence and species richness coinciding with restoration in the area >400 m downstream of the restoration. We conclude that increased abundance and diversity of aquatic vegetation was partially achieved, with observed improvements potentially linked to reduced wind fetch.     

River widening: an approach to restoring riparian habitats and plant species

‘River widenings’ are commonly used in river restoration to allow channel movement within a spatially limited area. Restoration seeks to restore fluvial processes and to re‐establish a more natural riparian community. This study investigates the performance of five river widenings in Switzerland, focusing on the re‐establishment of riparian (semi‐)terrestrial habitats and species, and highlights some factors that seem to influence their performance. The restoration projects are compared with pre‐restoration conditions and near‐natural conditions, which are assumed to represent the worst‐ and best‐case conditions along a gradient of naturalness. Fuzzy ordination of vegetation data and calculation of landscape metrics based on habitat maps revealed marked differences between the degree of naturalness achieved by each individual restoration project. However, in general river widenings were found to increase the in‐stream habitat heterogeneity and enhanced the establishment of pioneer habitats and riparian plants. Analyses of species pools based on a hierarchic list of indicator species and correspondence analysis showed that the ability of river widenings to host typical riparian species and to increase local plant diversity strongly depends on the distance to near‐natural stretches. Species dispersal and establishment might be hampered by decisions taken outside the scope of the restoration project. Therefore we conclude that action on the catchment scale is needed to maximize the benefits of local management. Copyright © 2005 John Wiley & Sons, Ltd.     

Process,Policy, and Implementation of Pool‐Wide Drawdowns on the Upper Mississippi River: A Promising Approach for Ecological Restoration of Large Impounded Rivers

The Upper Mississippi River (UMR) has been developed and subsequently managed for commercial navigation by the U.S. Army Corps of Engineers (USACE). The navigation pools created by a series of lock and dams initially provided a complex of aquatic habitats that supported a variety of fish and wildlife. However, biological productivity declined as the pools aged. The River Resources Forum, an advisory body to the St. Paul District of the USACE, established a multiagency Water Level Management Task Force (WLMTF) to evaluate the potential of water level management to improve ecological function and restore the distribution and abundance of fish and wildlife habitat. The WLMTF identified several water level management options and concluded that summer growing season drawdowns at the pool scale offered the greatest potential to provide habitat benefits over a large area. Here we summarize the process followed to plan and implement pool‐wide drawdowns on the UMR, including involvement of stakeholders in decision making, addressing requirements to modify reservoir operating plans, development and evaluation of drawdown alternatives, pool selection, establishment of a monitoring plan, interagency coordination, and a public information campaign. Three pool‐wide drawdowns were implemented within the St. Paul District and deemed successful in providing ecological benefits without adversely affecting commercial navigation and recreational use of the pools. Insights are provided based on more than 17 years of experience in planning and implementing drawdowns on the UMR. Copyright © 2015 John Wiley & Sons, Ltd.     

Challenging the assumption of habitat limitation: an example from centrarchid fishes over an intermediate spatial scale

Habitat rehabilitation efforts are predicated on the frequently untested assumption that habitat is limiting to populations. These efforts are typically costly and will be ineffective if habitat is not limiting. Therefore it is important to assess, rather than assume, habitat limitation wherever habitat rehabilitation projects are considered. Catch‐count data from a standardized probability‐based stratified‐random monitoring programme were examined for indirect evidence of backwater habitat limitation by centrarchid fishes in the Upper Mississippi River System. The monitoring design enabled fitting statistical models of the association between mean catch at the spatial scale of tens of river kilometres and the percentage of contiguous aquatic area in backwater at least 1 m deep by maximizing a stratum‐area weighted negative binomial log‐likelihood function. Statistical models containing effects for backwater limitation failed to account for substantial variation in the data. However, 95% confidence intervals on the backwater parameter estimates excluded zero, indicating that population abundance may be limited by backwater prevalence where backwaters are extremely scarce. The combined results indicate, at most, a weak signal of backwater limitation where backwaters are extremely scarce in the lower reaches, but not elsewhere in the Upper Mississippi River System. This suggests that habitat restoration projects designed to increase the area of backwaters suitable for winter survival of centrarchids are unlikely to produce measurable benefits over intermediate spatial scales in much of the Upper Mississippi River System, and indicates the importance of correct identification of limiting processes. Published in 2004 by John Wiley & Sons, Ltd.