珠江广州段水体微塑料的分布特征及迁移规律

全球海洋塑料污染日益严重,河流是陆地产生的微塑料向海洋传输的重要渠道。珠江微塑料的入海通量排名处于世界前列,其中流经广州市区的虎门入海口的贡献量远高于其他入海口。为探究珠江广州段支流水体微塑料的污染现状并厘清其影响因素,文章对珠江广州段(包括支流和入海口)18个典型采样点位的表层水体微塑料进行了综合分析。结果显示,微塑料的污染丰度为0.123~25.2个/m³。微塑料的主要类型包括聚乙烯、聚丙烯、聚苯乙烯等,其占比远高于其他类型微塑料。珠江广州段接收广州市区及周边城市排放的生活、农业和工业废水,其中纤维主要来自纺织品的洗涤,聚乙烯和聚丙烯均为生活中的常用塑料,聚苯乙烯和聚丙烯多用于生产各类塑料产品(如塑料玩具、泡沫箱等)。在4类监测断面(点)中,入境断面和监控断面的微塑料丰度远高于背景点和入海口。流经人口密集、城市化程度高的区域的支流微塑料丰度远高于其他支流,入海口微塑料丰度最低。可见,人类活动是影响微塑料在不同河段分布的最主要因素。     

入太湖河道大型底栖动物群落结构及水质生物学评价

于2020年9月在太滆运河、漕桥河、徐家大塘和竺山湾布设14个监测点位,调查入太湖河道底栖动物群落结构,并采用Goodnight修正指数（GBI）、生物学污染指数（BPI）和多样性指数（H）进行水质生物学评价。结果表明,研究区域共检出底栖动物6纲18种,霍甫水丝蚓（Limnodrilus hoffmeisteri）和中国长足摇蚊（Tanypus chinensis）为优势种,生物多样性由高到低为竺山湾（H=1.20）＞徐家大塘（H=1.09）＞太滆运河（H=0.67）＞漕桥河（H=0.33）。典范对应分析显示,总氮、正磷酸盐等因子与寡毛类生物量呈正相关,叶绿素a、IMn与摇蚊幼虫生物量呈正相关。生物学评价表明,太滆运河处于中重度污染状态,漕桥河、徐家大塘和竺山湾处于中度污染状态。     

Transport of pollutants in two estuarine systems on the coast of Georgia

The aim of the present study was to examine the distribution of pollutants in two coastal systems in Georgia: (1) Kubitskali river which flows into the Black sea through the city of Batumi and is polluted mainly from the effluents of an oil refinery; (2) Paliastomi lake, which is a shallow water body at the south-east of the city of Poti. During 2000-2001, two samplings took place in each system, one in the low-flow period and one in the high-flow period. During these samplings, pH, temperature, dissolved oxygen, and salinity were measured in situ, whereas water samples were collected for the analysis of trace metals, nutrients, and organic pollutants with standard methods. The results of the measurements indicate the significant pollution of both systems by ammonia and in the case of Kubitskali River also by oil products. The need for a sustainable management plan of the activities taking place in the river basin is urgent.     

塔里木河中游输水堤防外的地下水质变化分析

针对塔里木河中游输水堤防修建与生态保育的问题,结合对沙子河和阿其河两个断面地下水质的监测资料的分析,对输水堤防修建后堤防外地下水质的时空变化进行了探讨,揭示了在输水堤防影响下堤防外地下水质变化的初步规律.结果表明：沙子河断面和阿其河断面洪枯期地下水矿化度的变化规律由于堤防的修建而被改变,同样在堤防外侧,由于无地表水经过,沙子河断面地下水矿化度远高于在有生态闸定期放水的阿其河断面,因此,生态闸建设对抑制由于输水堤防影响而导致的水质修建具有积极作用.     

PERSPECTIVES FROM THREE YEARS EXPERIENCE OF REGIONAL WATER SERVICES IN THAMES WATER AUTHORITY1

ABSTRACT: Thames Water is one of ten regional Water Authorities established in 1974 to manage all water services in England and Wales. This paper looks back at water reorganization and reviews the achievements and highlights of the last three years. Constitutionally, Water authorities are a combination of a nationalized industry and local authority. This has advantages and disadvantages. Freedom of action, particularly in financial matters, is constrained by Government and official agencies. A severe pollution of the upper Thames and the drought of 1976 tested Thames Water's ability to deal with emergencies. Thames Water does not have an operational monopoly. Private Water Companies supply one third of the water demand and local authorities manage nearly all the sewers. But Thames Water's control over planning and investment ensures that the river basin is managed in a coordinated fashion. Tariff structure changes have led the Authority to bill all its consumers direct. The Thames is a small but intensively used river and vigilance is needed to maintain water quality. Thames Water is proud of the restoration of the tidal Thames from a typical grossly polluted metropolitan estuary to its present excellent condition. The British Government intends to establish a national water industry strategic planning organization but at the same time they affirm that there can be no departure from the principle of integrated river basin management.     

四川盆地油桐适宜栽培高度及分布

本文对油桐产油量立体变化与气候生态条件的关系进行了客观定量的研究,提出了油桐适宜栽培高度的气候生态指标;并结合四川盆地年平均气温分布特点,揭示了油桐适宜栽培高度的分布规律,还根据有关生态学和经济学原理,对油桐发展战略进行了探讨。     

RESEARCH: Comparison of Temporal Trends in Ambient and Compliance Trace Element and PCB Data in Pool 2 of the Mississippi River, USA, 1985–1995

6+ ), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), zinc (Zn), and polychlorinated biphenyls (PCBs). Water-column, bed-sediment, and fish-tissue (fillets) data collected by five government agencies comprised the ambient data set; effluent data from five registered facilities comprised the compliance data set. The nonparametric Mann-Kendall trend test indicated that 33% of temporal trends in all data were statistically significant (P < 0.05). Possible reasons for this were low sample sizes, and a high percentage of samples below the analytical detection limit. Trends in compliance data were more distinct; most trace elements decreased significantly, probably due to improvements in wastewater treatment. Seven trace elements (Cr, Cd, Cu, Pb, Hg, Ni, and Zn) had statistically significant decreases in wastewater and portions of either or both ambient water and bed sediment. No trends were found in fish tissue. Inconsistency in trends between ambient and compliance data were often found for individual constituents, making overall similarity between the data sets difficult to determine. Logistical differences in monitoring programs, such as varying field and laboratory methods among agencies, made it difficult to assess ambient temporal trends.     

River systems as providers of goods and services: a basis for comparing desired and undesired effects of large dam projects

In developing countries, large dam projects continue to be launched, primarily to secure a time-stable freshwater supply and to generate hydropower. Meanwhile, calls for environmentally sustainable development put pressure on the dam-building industry to integrate ecological concerns in project planning and decision-making. Such integration requires environmental impact statements (EISs) that can communicate the societal implications of the ecological effects in terms that are understandable and useful to planners and decision-makers. The purpose of this study is to develop a basic framework for assessing the societal implications of the river ecological effects expected of a proposed large dam project. The aim is to facilitate a comparison of desired and potential undesired effects on-site and downstream. The study involves two main tasks: to identify key river goods and services that a river system may provide, and to analyze how the implementation of a large dam project may alter the on-site capacity and downstream potentials to derive river goods and services from the river system. Three river goods and six river services are identified. River goods are defined as extractable partly man-made products and river services as naturally sustained processes. By four main types of flow manipulations, a large dam project improves the on-site capacity to derive desired river goods, but simultaneously threatens the provision of desirable river goods and services downstream. However, by adjusting the site, design, and operational schedule of the proposed dam project, undesirable effects on river goods and services can be minimized.