河湖水系连通分类体系探讨

河湖水系连通是保障国家水安全的治水新方略,科学的分类体系是开展河湖水系连通研究和生产实践的必然要求。论文结合河湖水系连通特点和内涵,提出五项分类原则:科学性、系统性、主导性、区域性和可操作性。综合考虑河湖水系连通的自然属性和经济社会属性,遵循五项分类原则,从连通性质、连通功能、连通区域、连通尺度、连通对象、连通时效、空间格局和连通方向等方面进行分类,初步构建了河湖水系连通分类体系,并对国内典型案例进行了归类;选择基于连通性质的分类、基于连通功能的分类和基于地区水资源特征的分类等三个主要分类展开分析,探讨了三种类型的连通特性、连通目标等主要问题。     

东江流域土壤、植被和悬浮物的碳、氮同位素组成

碳、氮同位素值对监测流域植被组成、环境变迁是一种非常有效的指标,为中短时间尺度环境变化研究提供了一条新的途径。以亚热带山区的东江流域为例,以流域内的植被、土壤及水体悬浮物为研究对象,应用其有机质同位素组成（δ13C、δ15N）,揭示流域植被的成分和环境变化的信息。研究发现：东江流域土壤碳同位素、C/N比值差值不大;植被的氮同位素差值明显,C/N比值差异较大。对东江流域悬浮物δ13C值近20年的监测表明：其值在早期逐年升高,近10年来转趋稳定并呈明显下降趋势,变化范围在-17.8‰～-26.1‰之间,反映了该流域植被破坏和恢复的过程以及土壤侵蚀状况的变化趋势。     

重污染河道中浮游植物初级生产力特征

通过对苏州城市河道的调查研究发现,城市河道的浮游植物初级生产力与其它水体有明显不同。从2004年6月至2005年5月通过取样分析苏州苗家河水体浮游植物种类、数量和叶绿素a含量变化及采用黑白瓶法测定浮游植物产氧能力,结果表明：该河道氮、磷含量较高,浮游植物群落为绿藻一硅藻型,种类少,季节变化明显,水体中表层叶绿素a的含量低于底层。分析表层水体和底层水体叶绿素a的产氧能力发现,河道中浮游植物的光合产氧能力普遍较低。本文揭示了重污染河道中大量悬浮颗粒附着在浮游植物的体表,影响了浮游植物的光合产氧能力,是整个水体和底泥中的溶氧普遍较低的重要原因之一。探讨了重污染河道溶氧偏低产生黑臭的原因,为重污染河道的综合治理提供了参考。     

Evaluation of aquatic rehabilitation technologies for polluted urban rivers and the case study of the Foshan Channel

An index system for evaluation of technologies for urban river rehabilitation was proposed and discussed. The index system includes indicators of cost, resources, environmental improvement, and social effects. The calculation method for an objective value of each index based on its attributes and weights was presented. The Foshan Channel, which is a seriously polluted, black and malodorous urban river in Foshan City, China, was selected as a case study. The values of the attributes and the weights of the indices for the Foshan Channel were determined. The technologies for the rehabilitation of the Foshan Channel were evaluated based on this index system. Finally, a rehabilitation scheme for the Foshan Channel was proposed.     

资源-环境双重约束下的区域生态效率的时序特征——以广西壮族自治区为例

为了探讨资源—环境双重约束下我国生态赤字地区资源环境绩效水平,利用生态脆弱指数和资源环境绩效指数（REPI）对地处珠江三角洲的广西资源环境绩效进行了系统分析和比较研究。结果表明：尽管资源环境绩效水平从2000年的72.4上升为2007年的116.1,但趋势并不明显,资源环境综合绩效水平在全国的第24—26位徘徊。综合绩效指数、SO2排放绩效指数、工业固体废弃物排放绩效指数和生物资源指数呈现＂N＂型变动,水污染指数下呈＂∧＂变动态势,大气污染指数呈现＂W＂型剧烈变动,生态承载力处于超载状态,生态脆弱性趋势没有明显改变。资源消耗和污染物排放的下降态势并不稳定。1995—2007年,广西区域环境水平呈下降趋势,区域环境水平和资源转化效率呈剧烈变动的下降趋势,抗逆水平和生态保护指数有所提高,土地资源指数呈现下降态势,排放强度指数下降明显,生态脆弱指数保持恒定,气候变异指数呈波浪状变动,环境治理指数呈剧烈变动。广西面临生态环境的整体不稳定性和对外力干预敏感性的双重压力。广西应发挥地处泛珠三角的地缘优势和辐射＂东盟＂的区位优势,加大结构调整和制度创新力度,缩短目前资源密集型的发展阶段,改善生态效率和承载力,提升广西在泛珠江三角洲地区的综合竞争力。     

基于相关系数优化法的河流突发污染源项识别

基于相关系数优化法,结合地表水环境特征和污染物水质过程特征,推导出一维河道中单点源瞬时排放的源项反演算法,得到了污染源排放特征与河流环境特征参数的反演公式.采用假想算例进行数值试验,综合分析了流速信息、污染物衰减、监测距离、监测数据误差及中间参数?T选取等因素对反演结果的影响,确定了该方法的适用条件和最优条件的寻找方式.间隔10min进行两次监测采样,若监测误差小于5%,反演结果的相关系数达到-0.97,污染源位置和排放量反演结果的相对误差均小于4%,综合相对误差在2%以内.并且方法具有监测布点简单高效,数据需求低,编程简单等优点,值得在环境应急管理中进行实际应用.     

河网城市不透水面的河流生态系统响应:方法论框架

河网城市不透水面快速扩展,已成为影响河流生态系统健康的主要因素,理解掌握区域不透水面与河流生态系统之间的压力响应关系十分必要。以国外研究为重点,从不透水面的识别技术方法、 流域不透水面与河流生态系统状况之间的压力响应关系、 不透水面在流域土地利用规划调控和河流管理应用等三个方面,回顾了不透水面研究的主要进展,特别对不透水面影响河流生态系统的阈值效应进行了较细致梳理。从研究区域、 研究视角、 研究方法、 决策应用等四个方面,讨论了当前研究可能存在的问题。结合河网地区较为特殊的水文地貌特点,提出了河网城市开展相关研究的主要任务,认为必须解决的若干关键技术方法问题包括:不透水面实地调查方法及与有效不透水面转换、 汇水单元及其多尺度体系、 压力响应体系构建,以及数据分析技术方法等。最后以上海地区为案例,分析了河岸带尺度上的不透水面与河流生态系统之间的压力响应关系。这一研究体系框架试图为相关实证研究提供可实际操作的方法论参考。     

基于空间数据的太子河河流生境分类

在文献调研的基础上,结合河流特征和专家经验确定分类使用的指标,利用DEM、河流水系等空间数据,在ArcGIS软件下提取子流域,并计算子流域内河流系统的坡降、蜿蜒度、河网密度和河流等级4个分类指标值,应用聚类分析方法对太子河河流生境进行分类,将太子河河流生境分为源头陡峭河流生境、源头弯曲河流生境、源头河流生境、支流中下游河流生境、平原支流密集河网生境、支流弯曲河流生境、干流下游生境和干流蜿蜒河流生境等8种类型,各类型河流长度在223.8~773.1km之间,其中支流弯曲河流生境最长,而干流下游生境最短. 根据各生境类型的特征,提出了我国东北地区河流生境分类的指标参考值;根据不同生境类型的河道侵蚀、水量以及多样性潜力等特征,提出了不同河流生境类型的环境管理对策.      

Impact of drought on the ecological and chemical status of surface water and on the content of arsenic and fluoride pollutants of groundwater in the province of Salamanca (Western Spain)

The impact of drought on the ecological and chemical status of surface and groundwaters of the River Tormes (River Duero basin, northwestern Iberian Peninsula) was studied to evaluate the evolution of the quality of the river during its passage through the city of Salamanca (Spain). The Water Quality Index (WQI) of the river revealed that the drought period of 2005 did not significantly affect water chemical quality. However, during the study period differences were found in surface water ecological quality, using phytoplankton quality as AN indicator. These differences may be accentuated as a result of regulation of the River Tormes by the Santa Teresa reservoir. Arsenic and fluoride concentrations were measured in water wells, finding higher arsenic concentrations after the drought period and no correlation between the arsenic and fluoride contents. The results are useful for an overall understanding of potential impact of climate change on the ecological and chemical status of water in regional systems.     

The Distribution and Impacts of Dioxins and Polychlorinated Biphenyls in the Taiwan Er-Jen River

Abstract

The distribution and impacts of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and polychlorinated biphenyls (PCBs) in the Taiwan Er-Jen River were investigated by monitoring fish distribution and measuring PCDD/DFs and PCBs levels in sediment and fish samples. Most of the fish collected are pollution-resistant species such as Oreochromis spp, Liza macrolepsis, Channa spp and Megalops cyprinoides. the most polluted river sections are in the upstream where large amount of waste effluents from households, livestock rearing and nearby dumping sites were discharged into the river, and the lower reaches of the river where metal recovery activities including open burning of waste electrical wire/scrap occurred. Sediment samples collected near the burning site show 2,3,7,8-TCDD toxicity equivalents (TEQ) ranging from 0.014 to 14.2 ng g^?1 by PCDD/DFs and from 0.015 to 1.03 ng g^?1 by coplanar PCBs (Co-PCBs). the fish samples show TEQ ranging from 0.029 to 0.615 ng g^?1 by PCDD/DFs and from 0.012 to 0.12 ng g^?1 by Co-PCBs. Possible PCDD/DFs sources are discharged PCBs, open burning of waste wire/scrap, and pentachlorophenol. the consumption of these fish will cause an average intake of 54 pg kg^?1 d^?1 TEQ. the prevention of direct discharge of livestock and the dumping of waste effuents into River Er-Jen as well as the control of metal recovery activities appears to be the first step toward the restoration of River Er-Jen.