Environmental change, land use and water quality in Scotland: current issues and future prospects

An outline of both the scientific and management needs facing the future water quality issues of Scotland is discussed. The scientific needs are considered in terms of monitoring to increase the understanding of hydrochemical processes, issues of scaling, and the need for improved modelling under changing environmental processes. In terms of the management needs, the requirements highlighted relate to improving the ecological quality of Scottish rivers and the implementation of integrated river basin management plans.     

The Roadford Scheme: Minimizing Environmental Impact on Affected Catchments

Roadford reservoir, located in the River Tamar catchment and commissioned in 1989, operates in conjunction with two other reservoirs and increased abstraction from six rivers in North and South Devon. The scheme affects the flow regime in all rivers, as well as their water quality, ecology and, particularly, their important salmon and sea trout fisheries. The paper describes how the detailed operating rules for the scheme have been designed to minimize the impact on the environment by means of changes to the flow regime, without jeopardizing the yield of the scheme. The complex operating rules include the zoning of the reservoir storage, varying prescribed minimum flows, spate sparing rules, and special releases for fisheries purposes. A programme of environmental monitoring will allow further refinement of the operating rules.     

ENVIRONMENTAL FLOW SETTING IN ENGLAND AND WALES: STRATEGIES FOR MANAGING ABSTRACTION IN CATCHMENTS

This paper describes the evolution of methods to set environmental flows in England and Wales. Problems and challenges are reviewed in the context of recent legislative developments, and examples are given of different conceptual approaches. Scenario-based approaches have evolved as a pragmatic means to resolve competing uses of water; in contrast, approaches based on ecological objectives aim to meet more consistent goals. Where rivers or associated wetlands have been designated under national or European conservation legislation, broad ecological objectives are already under discussion. Furthermore, the European Water Framework Directive now requires good ecological status, or its equivalent, to be reached in all waters. Recently, the Environment Agency has developed a new process for managing abstractions in England and Wales; this includes a common methodology for the setting of environmental flows using objective methods.     

水环境容量计算在污水系统规划中的应用

在污水系统规划中,扩大规模需要考虑纳污河流的环境承载力。利用一维水环境模型,计算了DQ县两纳污河流的水环境容量。结果表明,当前的环境剩余容量无法满足污水系统中远期规划的要求,上游来水断面的污染物浓度是提高剩余环境容量的重要约束条件。污水系统规模的扩大需要在改善现有水环境的条件下进行。     

Environmental flow assessment for rivers feeding a coastal wetland complex in the Pacific coast of northwest Mexico

Hydrological variability is one of the main drivers for rivers structure, and functionality, making the environmental flow (EF) assessment a key element to understand some ecological processes depending on it. Therefore, we aimed to evaluate the EF regime for the main rivers feeding a coastal wetland complex in northwest Mexico, following the hydrologic methodology officially approved by the Mexican National Water Commission based on daily data series (1975–2014). A mean annual runoff around 11 556 Mm³ was estimated to feed the Marismas Nacionales (MN) wetlands system from the discharge of seven rivers. It is expected that the estimated flows, regarded as necessary for the MN system to function properly as a whole, will change because of regional hydraulic infrastructure plans, threatening the discharge of the San Pedro and Baluarte rivers by reducing the flow significantly with negative effects on the MN wetlands.     

棕水变绿水——广州市东濠涌水环境及景观改造综合整治工程研究

古时广州是一座“河道如巷、水系成网”的水城,丰富的水资源使广州形成独具特色的城市水文化。在众多的河涌当中,东濠涌是广州仅存的古城护城河,至今已有六百多年历史。近代由于城市的发展,东濠涌由原来防洪排涝和水运为主的功能变成了以纳污为主,导致水环境污染日益严重。近几年,广州政府投入巨资治理东濠涌。该研究从水环境整治工程、生态河岸及景观整治工程两方面归纳东濠涌综合整治工程的思路与特．羔,表达了东濠涌综合整治工程对于改善城市生态环境所产生的积极影响,     

Investigating hydrologic alterations for wetland systems in terms of river environmental flows

Turkey's wetlands that represent a very diverse set of ecosystems are subject to considerable risks of biodiversity loss arising from the changes in their hydrology. Maintaining the full spectrum of naturally occurring flows in many rivers is almost impossible in Turkey's economically competing watersheds. Environmental flow assessments may still represent a compromise between water resources development and river ecology maintenance. In the presented study, changes in the water regimes observed in the period 1960–2000 are investigated together with concurrent ecological conditions for over 35 wetlands belonging to different ecological regions. The results, which are presented with indicator‐based risk figures to potentially correlate biodiversity loss to decreases in environmental flows in course of time, broadly indicate that substantial risks are estimated in Turkey in terms of environmental flows for wetland systems. Few exceptions appear in the north‐east in accordance with the recent climate change predictions indicating precipitation increase trends in the region.     

The environmental state of rivers in the Balkans—A review within the DPSIR framework

Fifteen major Balkan rivers with over 80% of the inflows in Eastern Mediterranean were examined for their environmental state within the DPSIR framework. Physicogeographic and hydrochemical conditions differ substantially among river basins, which may be roughly classified into three main zones. Despite strong fragmentation, most of the rivers are liable to flash floods and have low summer flow. Decreasing precipitation and (mis)management caused a dramatic discharge reduction over the last decades. Wars, political instability, economical crises over the past decades, combined with administrative and structural constraints, poor environmental planning and inspection and, frequently, a lack of environmental awareness imposed significant pressures on rivers. Large wetland areas were drained in favour of widespread intensive agriculture. The treatment of municipal wastewaters is barely adequate in Greece and insufficient elsewhere, while management and treatment of mining and industrial wastewaters is overall poor. In general, lowland river sections are hydro-morphologically modified and are at the greatest pollution risk, while upstream areas mostly retain their natural conditions. Nutrient concentrations in a number of central and eastern Balkan rivers often exceed quality standards, whereas pesticides and heavy metals, partly of geochemical origin, occasionally exceed quality standards. Reservoirs retain vast masses of sediments, thus adversely affecting delta evolution, while dam operation disturbs the seasonal hydrological and hydrochemical regimes. Almost all Balkan countries face daunting water resource challenges because of urgently needed investments in water supply, sanitation, irrigation, and hydroelectricity. International treaties and designations and European Union Directives have mobilized pollution mitigation and conservation efforts. However, the application of environmental legislation has proved in a number of cases inadequate. Constraints arise from long-standing top-down planning traditions, inadequate planning of national environmental policies, poor administrative capacities, and heavy investment requirements, often combined with a lack of environmental awareness.     

泾河平凉段水环境容量分析与对策

水环境容量是衡量一个水域水质状况的重要指标,泾河作为平凉市的主要河流,其环境状况与人们的生产、生活息息相关。将泾河平凉段分为三个控制单元,分别分析其属性和水质达标情况,在对污染源进行调查研究之后,采用一维模型计算其水环境容量,并将其与现行排污量进行比较,得出该流域的剩余水环境容量,同时提出了泾河平凉段水环境治理的具体对策。     

Taking the P out of pollution: an English perspective on phosphorus stewardship and the Water Framework Directive

Freshwater eutrophication is an international concern caused by increases in the supply of nutrients to water bodies from their catchments. It has been recognised as an issue in England since the late 1980s and 1990s. However, the problem had started to develop in earlier decades. The current state of play and future prospects in reducing phosphorus concentrations in English rivers and lakes are discussed. This includes an exploration of the challenges in attempting to achieve stringent phosphorus standards, in order to control eutrophication, while also wishing to manage phosphorus better, as a non‐renewable resource. Phosphorus stewardship ultimately needs to address both the resource efficiency aspects of phosphorus management and the environmental objectives. However, some tension between these aspirations is identified and potential future management approaches are outlined.     

Relationships between environmental metrics and water temperature: a case study of Polish lowland rivers

The article presents relations between environmental metrics and water temperature in small Polish lowland rivers and describes their spatial temperature patterns. Water temperature data was obtained from measurements conducted on nine sites during summer of 2015 with the use of digital data loggers. Selected environmental metrics in the catchments areas were calculated and correlated with water temperature parameters. The results showed that water temperature patterns were generally similar across catchments, except for sites with strong human influence, which caused a decrease in the number and power of statistically significant relationships between environmental metrics and water temperature parameters. The best‐explained water temperature parameter was the minimum and mean daily range, while the best environmental predictors were the Strahler order, catchment area, mean catchment elevation and forested area. Most of the relations proved to be theoretically justified and could be used to further improve temperature monitoring studies and the management of water resources.     

Sustainability of Scottish water quality in the early 21st century

This paper reviews some of the current water quality issues relating to the surface waters of Scotland and highlights some of the key issues likely to be significant over the next decade. The sustainable management of water quality requires an appreciation of the temporal and spatial assessment of the resource, together with an identification of reference or natural conditions from which to determine change, and the elucidation of the drivers of change. Only through this integrated approach, can appropriate management strategies be developed and prioritised, bearing in mind that impacts may be decoupled from sources in both time and space. This paper highlights recent trends in water quality (from a hydrochemical perspective) with separation into three broad groups: rivers, lochs and estuaries. For rivers, a general reduction in concentration of determinants that are more indicative of urban point sources (phosphorus, ammonium, suspended solids, biochemical oxygen demand etc.) is apparent, while in more agriculturally-dominated areas, an increase in concentration of solutes that are considered more diffuse in origin, (e.g. nitrate) is reported. The increasing contribution to total loads from diffuse pollutants is a priority area for both research and policy. Current scientific challenges are to define the most appropriate spatial context within which regional water quality issues can be monitored and managed. It is likely that future emphasis will be placed on making an initial ecoregion based grouping in conjunction with physically defined catchment, which will be used to quantify site-specific impacts. Such an organisational approach will provide a mechanism that enables a targeted monitoring strategy to be developed. This will allow the establishment of ecologically based targets for water quality, and an improved understanding the biogeochemistry of pollution reversibility and ecosystem recovery. It is also fundamental to the development of tools through which to predict the time scale and magnitude of any recovery, such that environmental benefit can be optimised against realistic socio-economic constraints. The inter-relations between water quality objectives and the development of legislation for water resources management in Europe are discussed.     

湛江市区域水环境容量的计算研究

通过建立污染源与水环境质量的响应关系，就湛江市污染物现状排放和水环境容量的计算、分配及水环境质量控制进行了研究。结果表明：湛江市CODM。的环境容量为163085t／a，NH3-N的环境容量为10636t／a；CODMn平均超标率为6．82％，NH3-N平均超标率为9．67％，该结果与污染物入河量、水质超标率的关系基本吻合，说明水环境容量的计算结果合理。此外，根据湛江市历年的降雨资料及相应的环境容量建立了湛江市降雨与环境容量曲线，为充分利用环境容量、做好排污治污工作提供了技术支持。     

Effectiveness of water protection policy in China: A case study of Jiaxing

The rapid economic growth in China has caused ever-increasing pollution and gradual deterioration of surface water quality over the whole territory of China since 1978. Along with it, there have been 130 environmental protection policies publicized and enacted. Unfortunately, even though these contradictory phenomena have coexisted for almost three decades, the cause analysis and the effective evaluation of policy measures are still rare. The Jiaxing region, a lowland located at the Taihu Lake watershed, is a typical representative of this dilemma and was proposed as a case study area for an assessment on the effectiveness of the environmental policy measures mentioned above. The pollutant loads originating from point pollution sources were discharged into rivers at fixed in-stream sites, while pollutant loads from non-point pollution sources in rural areas were assumed to be rushed into rivers by stormwater runoff. The environmental policy measures concerning water quality in the Jiaxing region were specified quantitatively as parameters for estimating the variation of pollutant loads. The base case and other three cases with the effects of policy measures were then simulated by the surface water quality models. The results show that a significant improvement of the surface water quality can be achieved by controlling the non-point pollution in rural areas and the point pollution over the whole area, if the water protection policies are sustainable and executed completely, and if the local government is active in their administrative, supervising and educational responsibilities and the farmers assume voluntary activities on rural pollution control.     

Geographically distributed classification of surface water chemical parameters influencing fate and behavior of nanoparticles and colloid facilitated contaminant transport

The current production and use of nanomaterials in consumer products have increased the concern about the possibility that these enter the rivers during their entire life cycle. Further, many aquatic contaminants undergo partitioning to the ubiquitous aquatic colloids. Here is presented the development of a set of European water types for environmental risk assessment of chemicals transported as nanovectors as is the case of environmental fate of manufactured nanoparticles and colloid-bound contaminants.     

Diatom assemblages distribution in catalan rivers, NE Spain, in relation to chemical and physiographical factors

Distribution patterns of epilithic diatom assemblages in streams in northeastern Spain and their relation to different environmental gradients are presented. Thirty-five sites were sampled covering a wide range of fluvial typologies. Gradient analysis was used to analyze the community structure and the major ecological gradients underlying variation in species composition. Two major gradients were evident; the first was a complex gradient from oligotrophic, pristine, fast-flowing highland rivers to mainly eutrophic rivers of low elevation; and the second related to altitudinal and seasonal variation of temperature. Two sets of factors were evident; one was associated with water chemistry, and the other to seasonal and physiographical variation. Variance partitioning allowed the separation of the effects of the different sets of environmental parameters. The contribution of physiography and water chemistry to diatom distribution was more unclear when the level of disturbance was intermediate. Considering the relatively high proportion of variation explained by physiographical variables alone, we suggest that when using diatoms to evaluate water quality, ecoregional characteristics of river stretches should also be considered.     

浅谈城市河流的绿化设计

在介绍了城市河流绿化特点、绿化用地范围及条件的基础上，阐述了树种选择的基本原则，并对城市河流绿化设计的原则、要点及其对水体、水体边缘、库边、滨河路等的设计进行了论述，最终达到生态、环境、经济的综合效益。     

Challenges and alternatives for unmanned underwater vehicular research in the Amazon basin: Towards a more sustainable management of water resources and the environment

The Amazon basin is one of the largest hydrographic systems in the world, possessing a great diversity of natural resources in need of more sustainable water and environmental management. However, as much of what lies beneath the surface of Amazonian waters is still unexplored, underwater exploration technologies are seen as a means of research and monitoring. The present work therefore aims to answer two research questions: What are the current technologies that could be implemented for unmanned underwater research in the Amazon waters? What are the main limitations and existing alternatives for using unmanned underwater vehicles in the rivers of this region to provide more sustainable water and environment management? Our results demonstrate that remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) are possible options in the short and long terms, respectively. The main challenges in implementing these technologies are related to the variations in hydraulic geometry, current velocities and turbidity of the rivers, as well as the preservation of the region's biodiversity. This research can be taken as a starting point for planners and decision makers seeking more sustainable underwater and environmental exploration of the Amazon river system.     

Long-term trends in water quality and their impact on macroinvertebrate assemblages in eutrophic lowland rivers

Long-term trends in water quality in eutrophic lowland rivers in eastern England were investigated and their impact on macroinvertebrate assemblages studied. Dissolved oxygen (DO) declined significantly in eight rivers in Essex and Suffolk over 40 years to 1998. Chloride concentrations significantly increased during the same period in most rivers. Total oxidized nitrogen and soluble reactive phosphorus increased until the 1980s, then began to decline. Biotic scores (Lincoln Quality Index) generally increased over 14 years to 1998 and there were significant positive relationships between biotic scores and several nutrients. Invertebrate families and environmental variables sampled over the eight rivers in a dry year (1997) and a wet year (1998) were subjected to multivariate analysis. River stretches were grouped according to substrate requirements of indicator invertebrates. In the dry year, those river stretches behind mills or immediately downstream of sewage treatment works (STW) were grouped. In the wet year, there was only one separate group, comprising sites downstream of STWs. Nutrients, DO and low flows have a much greater influence on water quality, and hence invertebrate assemblages, during drought years than during wet years.     

Predicted environmental concentrations of cocaine and benzoylecgonine in a model environmental system

A Mackay-type level II fugacity model has been used to predict the behaviour and final concentrations of cocaine (COC) and its main metabolite benzoylecgonine (BE) in a regional environmental system defined according to the European guidelines on Risk Assessment. The model takes into account the initial COC intake, partial degradation of the parent compound to BE, treatment of wastewater and environmental fate of these substances. Predicted environmental concentrations (PECs) lie in the ng L⁻¹ level, with the exception of the air compartment, where the concentrations are negligible. PECs in the water phase are in accordance with measured experimental concentrations in different European rivers. This case study shows that a simple level II fugacity model is suitable enough for modelling the environmental fate of high water soluble and low volatile organic compounds such as pharmaceuticals and personal care products.