Special Contribution: Managing the Great Lakes Basin as a Home

The ecosystem approach, a more holistic way to planning, research, and management of the Great Lakes basin, was articulated as a concept in the 1978 Great Lakes Water Quality Agreement. In order to stimulate movement of this concept to a series of implementable actions, an Ecosystem Approach Workshop was held in March 1983. This paper describes the process used to define common cause for a group of fifty-six participants representing a diverse spectrum of backgrounds. Three generic obstacles to attainment of an ecosystem approach, which emerged from pre-workshop efforts, were addressed by the workshop. They were: (1) lack of an holistic perspective, (2) predominance of “egosystem” thinking, and (3) lack of a preventive approach. The strategy suggested for overcoming the obstacles was identified as “enlightened self-interest”. The participants proposed 33 initiatives for advancing the ecosystem approach. These initiatives related to improving the acquisition of scientific data, directing institutional change for ecosystem management, improving citizen participation, paying the costs for resources use, education, and public awareness. In order to help implement these initiatives, establishment of an ecosystem approach monitoring group and an improved public information program is recommended.     

Commentary: Integrating non-targeted and targeted chemical screening in Great Lakes fish monitoring programs

The Great Lakes are a vital resource for drinking water and recreation and provide a major fishery for millions of people. As part of the Great Lakes Water Quality Agreement, the US and Canadian governments have been charged with the protection of this system. Persistent, bioaccumulative, and toxic (PBTs) contaminants were found to be affecting the lake water quality as early as the late 1960s, and various programs sponsored by the US and Canada have been created to monitor PBTs such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). These programs have refined measurement techniques to quantify trace level contaminants using a targeted analytical approach. However, new PBTs are being detected in the environment, and the traditional targeted methodology is inadequate for understanding the complex chemical mixture affecting Great Lakes wildlife. Fortunately, new analytical technologies are emerging that allow for comprehensive screening of PBTs beyond targeted methods. The current commentary presents an outline of a new framework for contemporary monitoring programs. The goal is to facilitate the compilation of legacy, emerging PBT, and archive PBT signatures by utilizing the basic practices of traditional targeted analysis. This example focuses on fish monitoring programs, and how they are ideally suited for legacy monitoring as well as data-driven discovery of new chemicals of concern.     

城市湖泊污水处理的实验分析

以西安市兴庆湖为研究对象,对湖泊的水质进行了水平潜流和自由表面流净化的实验研究,比较了两种湿地的净化效果。在相同的水力负荷、水力停留时间、水深等条件下,分析了两种人工湿地对城市湖泊中的有机物、氮、磷等主要污染物的净化效果,及不同影响因素对系统处理效果的影响,比较了两种人工湿地的优缺点。     

季节变化对人工湿地净化城市湖泊水体的影响

以西安市兴庆湖为研究对象,研究了季节变化对人工湿地净化城市湖泊水体效果的影响.结果表明:人工湿地对污染物的去除效果受季节变化的影响较大,秋季湿地对CODCr的去除率比冬季高19.58％,对TN的去除率比冬季高33.79％,而对TP去除率的影响不明显,对NH3 -N的去除率比冬季低20.03％.     

城市景观湖泊水体交换的数值模拟研究

通过水流数学模型模拟城市湖泊流场分布是评估水体交换能力的重要依据。利用二维水动力数学模型研究了惠州西湖的水动力优化调控方案,探明了惠州西湖各状条件下水动力较差的区域,评估了引水对于惠州西湖湖水动力的改善程度,并对比了不同方案的的引水效果,进而提出了较好的引水方案。其成果可为惠州西湖和其他城市湖泊水质改善工程提供参考和借鉴。     

以人为本 建设生态河湖—浅谈城市河湖规划与发展

北京作为举世闻名的历史文化名城,大量人工环境的建成以及由此带来的环境污染等一系列的负面影响,已对首都的可持续发展提出了严峻的挑战,城市河湖正在促进首都可持续发展战略的实施中发挥重要作用。     

水平潜流湿地对城市湖泊污水的净化分析

简要介绍了人工湿地的定义、分类和发展历史及现状,以西安市兴庆湖为研究对象,在水力负荷为0.5m3/（m2.d）和水深0.7 m时,分析水平潜流湿地对城市湖泊污水中的SS、COD、氮、磷等的净化效果,为人工湿地在西北地区城市湖泊的推广应用提供借鉴。     

温度变化对人工湿地净化城市湖泊水体影响研究

以西安市兴庆湖为研究对象,对湖泊的水质进行了水平潜流和自由表面流净化的实验研究。在相同的水力负荷、水深等条件下,分析了温度变化对城市湖泊中的有机物、氮、磷等主要污染物的净化效果的影响。实验结果表明,随着水体温度的降低,湿地对各污染物的去除率呈现减少的趋势。     

Managing Adaptation of Urban Water Systems in a Changing Climate

Current evidence is that climate change is occurring, it is largely manmade and it will have significant implications for human civilisation. Australia is particularly vulnerable to the anticipated effects of climate change, creating major challenges for water resource management and water supply security. Climate change adaptation offers a means by which we can reduce our exposure to future climate change risks, whilst at the same time exploiting any potential benefits that may arise from climatic changes. This review outlines the current major climate change adaptation challenges facing the water supply industry at large, with a particular focus on these challenges in an Australian context. It also aims to highlight the critical knowledge gaps and strategies required to assist in the formulation of adaptation responses to the range of potential impacts on water infrastructure and future water security. A diverse range of management and assessment techniques are used by relevant professions in industry. Here, an adaptive management approach is presented highlighting the important information required for robust assessment.     

水力停留时间影响城市湖泊污水处理的实验分析

以西安市兴庆湖为研究对象,对湖泊的水质进行了水平潜流和自由表面流净化的实验研究,比较两种湿地的净化效果。在相同的水力负荷、水深等条件下,分析了水力停留时间对城市湖泊中的有机物、氮、磷等主要污染物的净化效果的影响。     

Integrating remote sensing and species distribution modelling to predict benthic communities in a Great Lakes connecting channel

Species distribution models have become widespread in benthic ecology; however, they have mostly been applied to marine and lentic systems. In this study, we applied a maximum entropy model by using remote sensing‐derived environmental variables to predict the distribution of 4 major benthic communities dominated by Tubificidae, Naididae, Echinogammarus ischnus, and Dreissena spp, respectively, in the lower Niagara River, NY, USA. The model showed very good accuracy for benthic communities with a narrow distribution range (Tubificidae and Naididae) indicated by the area under the curve test values of 0.906 and 0.987, respectively. In contrast, the model showed poor performance for E. ischnus and Dreissena indicated by the low area under the curve values of 0.615 and 0.618, respectively. Both communities are known to cope with a wide variety of environmental factors and habitats, making their accurate predictions difficult using presence‐only data. Our results can further be used to locate important feeding grounds for higher trophic levels, to assess the potential spread of exotic species, and to identify areas for restoration.     

Greek Lakes: Limnological overview

The Institute of Inland Waters in Greece has investigated the physical, chemical and biological characteristics of major Greek lakes, with regard to water use, quality and trophic status. Based on this and other limnological investigations, Greek lakes can be divided into three categories: warm monomictic deep lakes, warm monomictic shallow lakes, and dimictic shallow lakes. The water quality of some Greek lakes demonstrates the presence of high concentrations of nutrients and heavy metals, with reduced concentrations of diluted oxygen. High concentrations of ammonia, nitrate and phosphate are found in many lakes, while anaerobic hypolimnia are usually found in shallow lakes. Phosphorus is the main nutrient responsible for eutrophication because it is the limiting factor in most of the lakes that were investigated.     

An appraisal of policy implementation deficits in the Great Lakes

Understanding of the complexities of both public policy implementation and Great Lakes restoration has grown in sophistication since the 1970s. The Great Lakes Water Quality Agreement is the principal policy for reversing environmental decline in the region. Implementation of this and related policies, particularly by the federal governments, suffers from acute and chronic deficits that we summarily document. These policy implementation deficits will continue to frustrate efforts to revitalize the Great Lakes unless significant advances are made to design governance processes within the Great Lakes regime that accommodate the complexity of linked social and ecological systems. The 2010-2011 governmental process to renegotiate the Great Lakes Water Quality Agreement is a potent opportunity to begin to overcome institutional barriers to reducing policy deficits. We argue that the renegotiation must begin a reinvestment in remaking or reimagining Great Lakes institutions in a way that restores capacity, flexibility, and moral authority. Our purpose is to help provide a foundation for that discussion.     

An appraisal of the Great Lakes advanced hydrologic prediction system

Great Lakes water level forecasts are used to inform decisions ranging from personal choices of recreational activities to corporate evaluations of alternative cargo transport options. For effective decision-making it is important that these model-based forecasts include an accurate expression of the forecast uncertainty, as well as information regarding the model forecasting skill. We provide an assessment of water level forecasts from 1997 through 2009 that were made using the National Oceanic and Atmospheric Administration (NOAA) Great Lakes Environmental Research Laboratory (GLERL) Advanced Hydrologic Prediction System (AHPS). A visual comparison between observed and forecast water levels suggests that AHPS generally captures seasonal and inter-annual patterns. A more quantitative assessment based on the percentage of observations within 90% prediction intervals, however, indicates that AHPS generally underestimates the observed variability of Great Lakes water levels. This assessment provides a benchmark for forecast performance against which alternative model structures (including future evolutions of AHPS) can be tested, and a basis to identify and prioritize the implementation of those alternatives. Including a calibrated model error term into the AHPS framework, to accommodate the underestimated variability, is a priority for short-term development and research, and represents one step toward more accurately quantifying forecast uncertainty. Our results also underscore the importance of storing historical forecasts and the data from which they were derived to serve as a basis for assessing model performance and prioritizing future model improvements.     

基质堵塞对人工湿地净化城市湖泊影响研究

以西安市兴庆湖为研究对象,研究了基质堵塞对水平潜流人工湿地净化城市湖泊水体的影响。针对利用基质进行过滤,生物量增长和分解,化学物质沉积和沉降时导致孔隙堵塞的问题,提出采用水解酸化预处理、间歇运行、药剂溶菌等方法解决。研究表明,基质堵塞问题的解决,使污水中悬浮物截流去除,可极大地提高后续湿地处理系统正常运行的可靠性。     

Pushing the Governance Boundaries: Making Transparent the Role of Water Utilities in Managing Urban Waterways

Integrated Water Resource Management (IWRM) requires simultaneous consideration of the multiple benefits that attend water. IWRM can also be more challenging in regulatory environments where the resource manager must justify choices and elements of each intervention. This is particularly challenging in the context of urban waterways that have many uses including an ecological function and a source of human amenity. To justify expenditure on maintaining and improving urban waterways for ecological and/or amenity changes regulated utilities must be able to articulate and measure these types of values with at least some degree of precision. This paper presents a generic and systematic framework for understanding the ecological and amenity values of urban waterways. We illustrate deployment of the framework in the case of Melbourne, one of Australia’s fastest growing cities and a location ranked as amongst the most liveable since 2011. We also explore how the results could improve the way we measure benefits in dollar terms.