The effects of aquatic invasive species on recreational fishing participation and value in the Great Lakes: Possible future scenarios

The impacts of aquatic invasive species (AIS) on the recreational fishery in the Laurentian Great Lakes are of concern to managers and policy makers. Some AIS have the potential to depress sportfish populations, reducing recreational fishing opportunities and damaging local economies. Alternatives that could reduce the threat of AIS could be costly. Assessments of how AIS could affect recreational fishing participation and the economic value derived from it would contribute to the evaluation of these alternatives. We assessed best-case and worst-case scenarios for how a range of AIS could affect recreational fishing participation and economic value. We utilized previously developed scenarios for how AIS could affect sportfish populations as input for a recreational fishing model developed by Ready et al. (2018). Their model estimated changes in fishing participation and economic value from such scenarios. Given uncertainty in how AIS could affect sportfish, projected effects of AIS on economic value varied widely, with some scenarios likely to have minimal effects and others leading to losses of over $100 million annually. None of the scenarios would lead to a large percentage decrease in recreational fishing in the eight Great Lake states, largely because anglers have numerous inland fishing opportunities. Nevertheless, lakeshore communities dependent on Great Lakes fishing could still suffer considerable economic loss. Collectively the economic valuation of the range of scenarios narrows down the possible impacts on fishing and the economy that decision makers need to consider.     

The Value of Steelhead (Onchorhynchus mykiss) Angling in Lake Erie Tributaries

Steelhead (Onchorhynchus mykiss) have been stocked in Ohio tributaries to Lake Erie for over a decade yet little information on the value of this fishery exists. A steelhead angler intercept survey was conducted in fall, winter, and spring of 2002–2003. Almost 77% of the anglers surveyed (375) responded to a mail survey with useful information. Typical steelhead anglers were 46 years old, middle class, male, and had 9 years steelhead angling experience. Less than two-thirds of respondents fished with spinning tackle and one-third used fly tackle. On average, individuals traveled with 1.7 people in their group. They mostly took single day trips (94% of respondents), traveling approximately 84 kilometers round trip. Steelhead catch rates are positively related to number of trips taken, angler experience, number of streams visited per trip, number of hours fished per trip, and type of tackle used. The value of the steelhead angling experience to participating anglers is estimated at $36 to $46 per trip while the money spent to participate in steelhead fishing is estimated at $26 per trip. Annual value of the Lake Erie tributary steelhead fishery in Ohio could be as high as $12 to $14 million compared to the $600,000 cost for the stocking program. The fishery provides economic benefits to the coastal areas where adequate access for stream steelhead anglers exists during parts of the year when recreational demand is lowest. This information can be used by policy makers to justify expenditures on stocking, public access, and water quality improvements that enhance angling.     

不同水质评价方法的应用比较研究——以丹江口水库入库河流为例

为准确了解丹江口水库直接入库河流水质状况及其主要污染因子,基于2015年16条入库河流河口水质监测成果,分别采用单因子评价法、综合污染指数法和主成分分析法对水质进行评价。3种评价方法均得出神定河、泗河和犟河水质较差的结论;筛选出的主要污染因子大致相同,为总氮、高锰酸盐指数、五日生化需氧量、氨氮和总磷;不同评价方法对河流水质状况评价结果和污染因子排序略有不同,单因子评价法只能给出评价类别,综合污染指数法和主成分分析法适用于不同时空的水质变化比较。结合当前丹江口库区水质管理工作,建议适当调整泗河、神定河、犟河水质管理目标,除水质类别外,建议增加主要污染因子的消减目标。     

基于补水配置情景的河流水质及环境容量研究

黄河最重要的子流域之一汾河流域是山西省的政治文化中心和重要农业产区,也是全国的主要能源基地,汾河流域目前面临严重的缺水与水生态问题,而生态补水是一项重要举措。为定量评价生态补水对流域水质与水环境容量的影响,本文构建了汾河水质水量联合模拟平台（FRSYS）,由5个子模型构成,以污染源调查计算和生态补水配置情景为基础,考虑了两种不同补水方案条件下,对汾河干流30个主要断面的水质状况与水环境容量进行了定量评价。结果表明,汾河流域年排放污染物COD和氨氮分别为5.34和0.96万吨/年,太原及其下游断面未能达到目标要求,太原、临汾断面的水质较差;现状水资源条件下汾河COD和氨氮的容量分别为2.67和0.14万吨/年,生态补水方案可有效改善水质状况,低生态补水方案补水2.5亿m3,对水环境容量影响不大,高补水方案补水3.9亿m3,可相应提高汾河干流COD和氨氮8%和12%的水环境容量。     

水环境公益诉讼的若干问题研究——域外环境诉讼制度对我国的启示

随着社会的发展和建立法治社会的要求，各国为了建立完善的法律法规体系，纷纷引入了公益诉讼的概念。近年来，飞快发展的经济建设同时引起了人们对水环境保护意识的重视，尤其是松花江水污染事件，更震惊了社会各界的关注。鉴于各国的发展历程，借鉴先进国家法律的相关经验与实践，对我国的水环境法治建设肯定会有裨益的。     

浅水湖泊水生态数学模型研究及应用

该文针对珠三角感潮浅水湖泊水环境模拟问题,在二维水流-污染物输移耦合数学模型基础上,结合WASP(water quality analysis simulation program)水生态数学模型原理,考虑溶解氧、氨氮、硝酸盐氮、有机氮、无机磷、有机磷、碳生化需氧量和叶绿素a等8个水质变量及其相互作用的溶解氧平衡子系统、氮循环子系统、磷循环子系统和浮游植物动力学子系统,建立了浅水湖泊水生态数学模型。通过室内实验系统模拟了珠三角某典型感潮人工湖泊外江来水营养条件对蓝藻生长的影响,确定了蓝藻生长速率等关键模型参数,并模拟了湖泊不同换水方案下叶绿素a的时空分布规律,为控制湖泊水体富营养化、预防蓝藻水华爆发提供科学依据。     

近10年辽河干流水质综合评价

针对辽河水质存在污染严重的问题,对其干流2008-2017年10年间的水质状况采用模糊综合评价和隶属度加权平均处理的方法进行了研究。结果表明:根据对水质的主要评价指标即溶解氧、化学需氧量和氨氮3个指标的综合评价与分析,铁岭朱尔山国控监测断面溶解氧的指标在3个评价指标中所占的最大权重是72%,盘锦兴安国控监测断面的溶解氧指标在3个评价指标中所占的最大权重是57%,两个断面水质的溶解氧指标平均值分别为7. 13和6. 66 mg/L,同时给出了水质变化的时空分布,2011年后朱尔山断面水质在2. 23~1. 34之间变化,2013年后兴安断面水质在2. 26~1. 36之间变化,朱尔山断面水质优于兴安断面,水质明显变好,治理成效显著。研究结果对辽河干流水质污染治理有重要意义。     

Characterization of water quality in a small hydropower plant reservoir in southern Brazil

The construction of large reservoirs can cause profound environmental changes. Reduced water flow, increased water residence time, thermal stratification, increased sedimentation rates and decreased dissolved oxygen concentrations are examples of such changes. These changes can affect water quality and the biota in the environments adapted to the natural conditions of a river. Small reservoirs developed in conjunction with hydropower plants, however, could reduce the degraded water quality. This study focuses on characterizing water quality in a small hydroelectric reservoir. The study reservoir has an area of 1.4 km² and a short water retention time. The Monte Claro Hydroelectric Power Plant is part of a complex consisting of three plants on the Antas River in the north‐west of Rio Grande do Sul state, Brazil. The reservoirs associated with these plants are operated as run‐of‐the‐river facilities. Monitoring results obtained by CERAN, the Energetic Company of Antas River (Companhia Energética Rio das Antas), were used to evaluate the reservoir water quality. Three samples were collected seasonally (spring, summer, autumn and winter) in the area of influence of this plant following the filling of the reservoir (2005–2008). The examined water quality parameters were electrical conductivity, colour, turbidity, alkalinity, pH, biological oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus, dissolved oxygen, sulphate, nitrate, nitrite, ammonia, suspended and dissolved solids, chlorophyll‐a, total and faecal coliforms, water temperature and Secchi depth transparency. The results were interpreted using an index of water quality, Trophic State Index, reservoir water quality and CONAMA Regulation 357/05 (Brazilian legislation). Based on these analyses, no significant changes were exhibited in the water quality of the reservoir from the hydroelectric plant operation.     

The Volga: Management issues in the largest river basin in Europe

The Volga is the longest river in Europe and 16th longest in the world. The riverine landscape of the Volga is of exceptional scientific and economic importance to Russia; the basin contains approximately 40% of the Russian population and relates to 45% of the country's industrial and agricultural produce. The Volga River drains an area of 1.4 million km², covering various biomes from taiga to semidesert. Anthropogenic impacts in the 20th century include pollution as well as hydropower production and navigation purposes, incurring a cost for its historically important migratory fish (e.g., sturgeons) and related fisheries. River basin management in Russia, since 2006, is based on the water code that determines federal competencies in water management. Extensive water quality monitoring programmes provide feedback to regional managers. Monitoring of biological parameters is spatially limited and should be extended in order to provide sufficient data for informed management. Some initiatives have been implemented in recent decades in order to restore the ecological health of the river and manage fisheries resources (e.g., restocking programmes and the definition of total allowable catches). As recreational fishing is popular but presently unregulated in Russia, we suggest additional monitoring. Finally, the headwaters and lower river floodplain of the Volga have remained as free‐flowing and relatively undisturbed systems. Because reference conditions with low levels of anthropogenic disturbance cannot be found in Central European lowland rivers, both the headwaters and lower Volga floodplains below Volgograd are of great importance on European level.     

Integrated Economic-Hydrologic Assessment of Water Management Options for Regulated Wetlands Under Conditions of Climate Change: A Case Study from the Spreewald (Germany)

This paper presents an integrated economic-hydrologic approach for the assessment of water management options for wetlands. It is based on a water resources modelling framework for long-term basin planning, that is augmented to model ecosystem service provision levels of wetlands as a function of water availability and water management. The approach is applied to a case study of the Spreewald wetland that is major fen wetland in the mid-reaches of the River Spree (Germany). Different management options at the wetland and basin scale are assessed in a cost-benefit analytical framework regarding their performance under projections of future climatic conditions. The cost-benefit analysis is based on the valuation of important wetland ecosystem services: grassland fodder production, recreational boating, habitat and biodiversity conservation and regulation of greenhouse gas emissions. It is found that under future climatic conditions, regulated and drained wetlands such as the Spreewald will require an increasing amount of water to maintain the current levels of benefits derived from the wetlands ecosystem services. Additional inter-basin water transfer could compensate some of the negative effects of increased water demand. However, the assessed transfer option is not economically efficient. Water management approaches that increase the intra-annual water storage in the wetland soils by higher groundwater level regulation targets are found to generate net gains in benefits compared to the current water management without any increase of the water supply.     

黄河流域实施水功能区限制纳污红线管理的整体构想与初步实践

水功能区限制纳污红线管理是实行最严格水资源管理制度的核心内涵之一。黄河流域水安全问题是中国水安全问题的缩影,探索构建行之有效且具有黄河流域特色的纳污红线管理制度体系和工作格局,对于提高黄河流域水安全保障能力意义重大。针对黄河流域的水资源质量状况,探索建立流域与区域相结合、水利与环保相联合的黄河水资源保护管理体系,构建流域水功能区划及水资源保护规划体系,依法强化以入河排污口为重点的水功能区管理,积极探索水生态系统保护与修复,加强水质监测网络体系建设等一系列措施,为黄河流域实施纳污红线管理提供了良好的工作基础和能力支撑,并在此基础上阐述了黄河流域实施纳污红线管理的整体构想与初步实践。     

Historical Changes in Fish Assemblage Composition Following Water Quality Improvement in the Mainstem Trinity River of Texas

The Clean Water Act of 1972 is credited with improving water quality across the USA, although few long‐term studies tracking hydrologic, chemical, and biological responses to cleanup efforts exist. The Trinity River of Texas was plagued by poor water quality for more than a century before passage of legislation to reduce point source pollution from the Dallas–Fort Worth (DFW) Metroplex. We tracked changes in components of flow regime; concentrations of ammonia, nitrate, phosphorus, and biochemical oxygen demand (BOD); and fish assemblage composition in three mainstem reaches during a 40‐year period (1968–2008) following implementation of a large‐scale cleanup initiative. Results suggest little change in flow regime components such as magnitude, timing, and rate of change among the three reaches during 1968–2008. Concentrations of water quality parameters declined through time and with greater distance from DFW, including the lowest concentrations in the reach downstream of a mainstem reservoir (Lake Livingston). Fish assemblage composition shifts correlated with attenuated nutrient and BOD concentrations, and species richness generally increased among all reaches. Native and intolerant fishes consistently increased through time among all three reaches, although lentic and non‐native species also increased downstream of Lake Livingston. Our findings suggest a revitalization of the Trinity River fish assemblage associated with reduced nutrient pollution in DFW (even among distant reaches) and also illustrate potential confounding factors such as stream impoundment and continued nutrient deposition that likely preclude complete recovery. Copyright © 2014 John Wiley & Sons, Ltd.     

Hydrology and aquatic habitat characteristics of a riverine swamp: I. Influence of flow on water temperature and chemistry

We monitored water temperature, air temperature, hydrologic characteristics, and chemical variables for 25 months in a 254‐km² portion of the Atchafalaya Basin, Louisiana, USA, a distributary swamp of the Mississippi River. We related observed trends in thermal and chemical variables to characteristics of the flood pulse, available channel types, and paths of water flow within the study area. Dissolved oxygen (range 0.05–13.05 mg L⁻¹), percent oxygen saturation (range 0.6–142.4%), and pH (range 6.31–8.52) increased as river stages decreased, and water temperatures (range 4.75–32.25°C), specific conductance (range 207.8–931.5 μmhos), and the top–bottom difference in dissolved oxygen (−7.5–12.05 mg L⁻¹) increased as air temperatures rose. The maximum variance observed for all chemical and thermal habitat characteristics occurred during periods when air temperatures exceeded, and river stages were less than, their respective medians observed during the study. At any point in time, thermal and chemical variables varied most among stations in water courses with no visible water turbulence (low‐energy channels), and these channels consistently had lower dissolved oxygen, percent oxygen saturation, and pH than turbulent water courses (high‐energy channels) or lakes contained. Water was directed from the river into one region of the study area from two opposing directions, thereby impeding water flow through the region. Low‐energy channels in this region consistently exhibited lower dissolved oxygen concentrations, percent oxygen saturation, and pH than was observed in low‐energy channels of regions where water flow was unimpeded. The quantity and quality of aquatic habitat characteristics in riverine swamps can be manipulated by controlling the timing and magnitude of the flood pulse, relative availability of different water courses, and internal paths of water flow through the swamp. Copyright © 1999 John Wiley & Sons, Ltd.     

基于EFDC模型的尾水回用于城市景观水体优化计算

以昆山市内蓬朗污水处理厂深度处理后的尾水回用于城市景观水体夏驾河为例,以环境流体动力学模型(environmental fluid dynamic code,EFDC)构建的夏驾河三维非稳态水量模型为基础,考虑经济、社会、环境等多方面的效益,构建目标函数,研究6种设计情景下尾水回用的综合效益,确定污水处理厂尾水回用的最佳运行方案。结果表明,从经济、社会、环境效益最大化的角度出发,昆山市夏架河尾水回用最优方案为:出水口选为距太仓塘4.5 km处,排水方向为吴淞江,回用流量为3.4万m3/d。尾水回用于景观水体可以有效改善水体交换,蓬朗污水处理厂尾水入河位置及回用量流量直接影响夏驾河换水周期以及夏驾河水质的好坏。     

张家河梯级水电站建设生态环境影响与对策探析

张家河梯级水电站坐落在河栏镇张家村,位于青凤寺张家沟河上,电站利用引兰入汤工程的引水流量发电,合理、充分地利用了现有的水能资源。张家河梯级水电站的建设提高了兰河流域水能资源的开发利用率,缓解了地方电网的矛盾,提高了地方电网的运行质量,经济效益十分显著。从技术角度分析,水电站的建设利大弊小;从环境角度看,水电站的修建是可行的。     

A socioeconomic analysis of habitat restoration in the Muskegon Lake area of concern

As part of the 2009 American Recovery and Reinvestment Act (ARRA), a $10 million grant was awarded to restore wetlands and stabilize shoreline along the south shore of Muskegon Lake (MI), a Great Lakes Area of Concern. A socioeconomic analysis was conducted as part of this award, which included a travel cost survey for lake recreation and a hedonic housing valuation to estimate return on investment. The value of a trip to Muskegon Lake was estimated to be $39.76; when applied to the anticipated increase in post-restoration recreational trips to Muskegon Lake, and using a conservative 7% discount rate, the Net Present Value over 20 years is $38.1 million. The hedonic analysis examined values for houses between 100 and 800 m from the shoreline, using both the current shoreline distances and the new shoreline distances after restoration; this resulted in a predicted $11.9 million in additional housing value as a result of the improved shoreline features. Summing the hedonic value and travel cost estimates, along with the original $10 million spent, the result is that over 20 years, the total value generated for the local region is nearly six times the initial ARRA spending. In other words, of the $60 million of value created on the Muskegon Lake restoration, $50 million is increased environmental value over the 20 year period.     

基于混合算子遗传算法的水资源优化配置

构建了以经济效益、社会效益、生态效益为多目标的水资源配置模型,针对模型中存在的多目标多约束优化问题,对基本遗传算法进行改造,设计了一个混合算子遗传算法,并用算例进行验证,最后将水资源优化配置模型和算法应用于东江流域。实例计算结果表明,基于混合算子遗传算法的多目标水资源优化配置模型配置结果合理可行,可作为研究流域水资源配置的决策依据。遗传算法作为新型智能算法,可应用于水资源配置领域。     

Habitat suitability modeling of a conservation-significant fish species of the Kosi River,Uttarakhand, India

Water quality plays a vital role in the sustenance of aquatic life, including fish. Therefore, an inclusive understanding of water quality parameters can be considered an essential step in framing the conservation and management strategy of an aquatic ecosystem. This study examines the habitat suitability of a conservation-significant fish, the Tor putitora, and two associated fishes, the Labeo dyocheilus and the Garra gotyla, in relation to the water quality parameters of the Kosi River. Four crucial water quality parameters, water temperature, dissolved oxygen, electrical conductivity, and pH, were included in the QUAL2K modeling. Furthermore, hydrological processes were modeled using the soil and water assessment tool, and flow was used as an input in the QUAL2K model. The simulated water quality was correlated with fish habitat and analyzed through the analytical hierarchical process (AHP). Results suggested that the habitats of the Kosi were more suitable in the post-monsoon rather than pre-monsoon. Tor putitora, the flagship species of the Kosi, preferred the river habitats with a lower water temperature and higher dissolved oxygen for spawning. Thus, we recommend securing such habitats and managing them in collaboration with local communities for the long-term conservation of this endangered Himalayan species.     

LM—BP神经网络在于桥水库水质预测中的应用

利用BP神经网络的改进算法（L-M）,通过对大量样本进行多次的训练学习,建立于桥水库水质预痢模型,用该模型对于桥水库高锰酸盐指数、五日生化需氧量、氨氮、溶解氧等污染指标进行了预测,预测结果表明,LM—BP神经网络模型用在于桥水库水质预测时是可行的,可以得到较为理想的的精度和可靠度。     

通榆河枢纽水利风景区建设与管理的探索

区域的生态效益与经济效益通常是一对难以通过工程手段解决的矛盾。江苏省盐城市通榆河枢纽工程管理处积极依靠自身力量，通过水土保持生态景观开发，建设国家级水利风景区，不仅使水利资源得到合理的开发和科学的利用，而且促进了水利工程的安全运行，取得了显著的生态效益和经济效益。同时，也为基层水管单位进行水利风景区的开发建设与管理探索，从而实现从工程水利向资源水利转变，从传统水利向现代水利、可持续发展水利转变，作出了有益的尝试。