基于社区尺度的生态安全研究——以苏州地区为例

随着近20年来经济的飞速发展,苏州地区已成为我国城镇化程度较高的地区之一。人们的生活水平有了很大的改善,但生态环境问题也日益突出,生态环境问题已经上升到了生态安全的角度。目前有关生态安全的理论还尚不成熟。本文在前人研究的基础上,从环境、社会、经济三个角度出发在社区这个小尺度范围内结合苏州近期社区建设探讨了苏州区域社区生态安全。     

无机碳对浮游藻类生长和群落结构的影响

采用水族箱生态模拟方法,利用碳酸钠和碳酸氢钠作为碱度调节剂设置不同碱度水平,研究了氮磷营养相对充足的试验水体中藻类各相关指标对无机碳的响应,并对试验过程中所测得的理化指标和生物指标进行统计分析.研究表明:富营养水体无机碳含量与藻类叶绿素水平存在着正相关关系;适当增加水体中的无机碳浓度能够改变蓝、绿藻门种类比例;当碱度水平达到一定程度时,铜绿微囊藻可以逐渐成为优势种,并从体系中上升,演替成为水华.     

Effects of a herbicide-insecticide mixture in freshwater microcosms: risk assessment and ecological effect chain

Effects of chronic application of a mixture of the herbicide atrazine and the insecticide lindane were studied in indoor freshwater plankton-dominated microcosms. The macroinvertebrate community was seriously affected at all but the lowest treatment levels, the zooplankton community at the three highest treatment levels, with crustaceans, caddisflies and dipterans being the most sensitive groups. Increased abundance of the phytoplankton taxa Cyclotella sp. was found at the highest treatment level. Threshold levels for lindane, both at population and community level, corresponded well with those reported in the literature. Atrazine produced fewer effects than expected, probably due to decreased grazer stress on the algae as a result of the lindane application. The safety factors set by the Uniform Principles for individual compounds were also found to ensure protection against chronic exposure to a mixture of a herbicide and insecticide at community level, though not always at the population level.     

Volatile organic compounds at swine facilities: A critical review

Volatile organic compounds (VOCs) are regulated aerial pollutants that have environmental and health concerns. Swine operations produce and emit a complex mixture of VOCs with a wide range of molecular weights and a variety of physicochemical properties. Significant progress has been made in this area since the first experiment on VOCs at a swine facility in the early 1960s. A total of 47 research institutions in 15 North American, European, and Asian countries contributed to an increasing number of scientific publications. Nearly half of the research papers were published by U.S. institutions.Investigated major VOC sources included air inside swine barns, in headspaces of manure storages and composts, in open atmosphere above swine wastewater, and surrounding swine farms. They also included liquid swine manure and wastewater, and dusts inside and outside swine barns. Most of the sample analyses have been focusing on identification of VOC compounds and their relationship with odors. More than 500 VOCs have been identified. About 60% and 10% of the studies contributed to the quantification of VOC concentrations and emissions, respectively. The largest numbers of VOC compounds with reported concentrations in a single experimental study were 82 in air, 36 in manure, and 34 in dust samples.The relatively abundant VOC compounds that were quantified in at least two independent studies included acetic acid, butanoic acid (butyric acid), dimethyl disulfide, dimethyl sulfide, iso-valeric, p-cresol, propionic acid, skatole, trimethyl amine, and valeric acid in air. They included acetic acid, p-cresol, iso-butyric acid, butyric acid, indole, phenol, propionic acid, iso-valeric acid, and skatole in manure. In dust samples, they were acetic acid, propionic acid, butyric acid, valeric acid, p-cresol, hexanal, and decanal. Swine facility VOCs were preferentially bound to smaller-size dusts.Identification and quantification of VOCs were restricted by using instruments based on gas Chromatography (GC) and liquid chromatography (LC) with different detectors most of which require time-consuming procedures to obtain results. Various methodologies and technologies in sampling, sample preparation, and sample analysis have been used. Only four publications reported using GC based analyzers and PTR-MS (proton-transfer-reaction mass spectrometry) that allowed continuous VOC measurement. Because of this, the majority of experimental studies were only performed on limited numbers of air, manure, or dust samples. Many aerial VOCs had concentrations that were too low to be identified by the GC peaks.Although VOCs emitted from swine facilities have environmental concerns, only a few studies investigated VOC emission rates, which ranged from 3.0 to 176.5 mg d⁻¹ kg⁻¹ pig at swine finishing barns and from 2.3 to 45.2 g d⁻¹ m⁻² at manure storages. Similar to the other pollutants, spatial and temporal variations of aerial VOC concentrations and emissions existed and were significantly affected by manure management systems, barn structural designs, and ventilation rates.Scientific research in this area has been mainly driven by odor nuisance, instead of environment or health concerns. Compared with other aerial pollutants in animal agriculture, the current scientific knowledge about VOCs at swine facilities is still very limited and far from sufficient to develop reliable emission factors.     

Evaluation of the Community Multiscale Air Quality (CMAQ) model version 4.5: Sensitivities impacting model performance: Part I—Ozone

This study examines ozone (O₃) predictions from the Community Multiscale Air Quality (CMAQ) model version 4.5 and discusses potential factors influencing the model results. Daily maximum 8-h average O₃ levels are largely underpredicted when observed O₃ levels are above 85 ppb and overpredicted when they are below 35 ppb. Using a clustering approach, model performance was examined separately for several different synoptic regimes. Under the most common synoptic conditions of a typical summertime Bermuda High setup, the model showed good overall performance for O₃, while associations have been identified here between other, less frequent, synoptic regimes and the O₃ overprediction and underprediction biases. A sensitivity test between the CB-IV and CB05 chemical mechanisms showed that predictions of daily maximum 8-h average O₃ using CB05 were on average 7.3% higher than those using CB-IV. Boundary condition (BC) sensitivity tests show that the overprediction biases at low O₃ levels are more sensitive to the BC O₃ levels near the surface than BC concentrations aloft. These sensitivity tests also show the model performance for O₃ improved when using the global GEOS-CHEM BCs instead of default profiles. Simulations using the newest version of the CMAQ model (v4.6) showed a small improvement in O₃ predictions, particularly when vertical layers were not collapsed. Collectively, the results suggest that key synoptic weather patterns play a leading role in the prediction biases, and more detailed study of these episodes are needed to identify further modeling improvements.     

大港发电厂温排水对附近海域浮游动物影响研究

分别于2010年夏、冬季对大港发电厂温排水口附近海域浮游动物进行调查。结果表明:调查区浮游动物以桡足类和幼虫类占优势,群落结构相对稳定,但丰度明显低于渤海湾其他海区,种类组成、丰度和多样性指数具有夏季高于冬季、近岸低于远岸的时空变化特征。临近温排水口的TJHS1117站位的浮游动物群落物种数、丰度及多样性等在6个调查站位中都处于最低,可见温排水对浮游动物群落结构及平面分布有一定的影响。     

太子河流域大型底栖动物水质评价及指数分析

分析了太子河流域大型底栖动物群落结构,采用大型底栖动物Chandler生物指数、Shannon-Wienner多样性指数、BMWP-ASPT记分系统、BI指数,对2015年度平水期太子河流域进行了水质生物评价,对以上4个指数的结果进行了Pearson相关性分析,讨论了各生物指数的适用性。将BI指数的评价结果与理化结果进行了比较分析。结果表明:BI指数更适于太子河流域开展水质生物评价。     

大纵湖大型底栖动物群落结构与水质生物学评价

2013年1月中旬对大纵湖5个采样点的大型底栖动物进行调查,共采集底栖动物29种,其中DZ1的优势种为苏氏尾鳃蚓(Branchiura sowerbyi);其他各点的优势种为长角涵螺(Alocinma longicornis)。采用理化分析、Shannon-Wiener指数、Margalef指数、BPI指数对各点水质进行了综合评价。结果表明:DZ4属于β-中污染水质,其他各点属于α-中污染水质;对主要的环境因子与底栖动物密度进行相关性分析,发现DO与底栖动物群落未显著相关,NH3-N、NO-3-N、CODMn等因子更能代表水体的污染水平和营养状态,且随着营养状态的升高,耐污种类的颤蚓类数量呈现出增高趋势;寡毛类、蛭类、摇蚊幼虫、水生昆虫和软体动物5者之间除了寡毛类和蛭类存在极显著正相关性之外,其他无显著相关性。     

Water, women and community in Trinidad, West Indies

This article examines the history and character of the water supply in Trinidad and Tobago and the nature of problems associated with the procurement of water by Trinidadians. The article reports on case studies of two rural communities in which women have taken the lead to solve water problems. It reflects on the importance of small‐scale, community‐managed water systems for the possibility of achieving water democracy.     

Improving public information about large hydroelectric dams: Case studies in France and West Africa

It is becoming more common for public authorities in charge of dam construction and management to inform the population living in the area soon to be submerged by a proposed dam. However, populations living further downstream along a river to be dammed, have often been left to find out by chance, despite the fact that the changes to the river flow regime will have an important impact on their lives, sometimes serious negative impacts. This article makes a comparison between two dams, one at Bort-les-Orgues across the upper Dordogne River in southern France, the other the Bagré Dam over the Nakambé (or White Volta) River in south-eastern Burkina Faso. The article discusses dam construction and operation from the point of view of the concerned populations living in the reservoir and downstream areas.
In 2000, a study was carried out in the Dordogne Valley to ascertain downstream impacts of dam operations and information needs of the population. Suggestions from local river users related mostly to improving public information about predicted and actual flow rates and actual flow in real time along the 300 km course of the Dordogne between the dams and the estuary. Such information should be disseminated as widely as possible through available media, including the Internet, and also displayed visibly in key locations along the length of the river.