淡水藻类在监测水质和净化污水中的应用

淡水藻类作为水体中的初级生产者,分布广泛,适应性强,在水生生态系统食物链中占据着十分重要的地位,在水质监测中起着关键的作用。通过对藻类生长与水环境之间的相互关系进行简要的概述,探讨了pH值和氮磷对淡水藻类的生长的影响,以及淡水藻类的生长对外界环境的影响。藻类不但应用于水质监测,而且还能去除水体中的氮、磷等营养物质和其它有机物,对自然水域中的污水有良好的净化作用。重点论述淡水藻类在水质监测和污水净化中的作用以及利用淡水藻类来处理污水的方法。并提出了保护水资源的相关建议,为综合监测和治理水环境提供一定的理论依据和支持。     

肇庆市七星岩里湖水化学因子相关性研究

广东省肇庆七星岩是我国著名的风景游览胜地 ,里湖是其中的重要组成部分。面积约 2 .6× 1 0 5 ｍ2 ,近年来 ,里湖水质有劣化趋势 ,表观上出现不同颜色 ,有藻类突发现象。对景区产生不良影响。既往研究表明 ,影响里湖水质的关键组分除浮游藻类叶绿素ａ与氮、磷含量之外 ,水中的ＤＯ和ＣＯＤ、ＢＯＤ也是极其重要的指标。研究它们的相互关系 ,旨在探讨其内在联系及变化规律 ,对于湖泊生态环境的保护和水污染的治理具有重要意义。1　研究材料与方法1 .1　主要仪器日立Ｆ -30 0 0型荧光分光光度计 (日本) ;ＷＺ -80 0Ｄ2 型紫外分光光度计(北京…     

气候变化对水文水资源的影响分析

气候变化已成为最近几十年来最受瞩目的环境问题,全球气候变暖及由此引起的水文地质灾害、水资源短缺已成为国际、国内学术研究的热点。水资源是地球上最宝贵的自然资源,也是人类乃至整个生物圈赖以生存的基础。研究气候变化对水资源的影响,对于今后水资源的合理开发、利用、管理和保护具有非同寻常的意义。有鉴于此,本文分析和总结了近代到现代气候变化趋势以及对水文水资源的影响。     

水资源短缺的社会适应能力理论及实证--以黑河流域为例

水资源短缺已成为制约干旱-半干旱内陆河流域可持续发展的瓶颈,社会适应能力理论为解决水资源短缺问题提供了新的思路和方法。从人类生态系统角度分解社会适应能力,辨明了社会适应能力结构性成分,并利用网络层次分析(ANP)方法,构建了缓解水资源短缺的社会适应能力定量评价模型。然后以黑河流域中游甘州区为研究区,进行了水资源短缺的社会适应能力定量评价的案例研究。结果表明研究区缓解水资源短缺的社会适应能力综合指数为2.411,处于中等水平,有待进一步提高;在灌区尺度上,缓解水资源短缺的社会适应能力水平与受灌区水资源管理背景和意识的影响。在缓解水资源短缺的社会适应能力系统中,研究区有两个关键资源有所欠缺,同时人口自然增长率和人均综合用水量较低、社会公平和节水意识水平相对较高,但人们安全感和政策稳定性不强并缺乏信任,廉政水平、政府管理能力和社会经济资源水平需要进一步提高。旨在为水资源可持续利用研究提供一种新的分析角度,为决策者采取新的社会、经济、制度等对策提供科学依据支撑。     

序言

<正>土壤是人类赖以生存和发展的物质基础。当前,世界粮食安全、环境污染、淡水资源紧张、能源短缺、气候变化、生物多样性锐减等各种问题并存,土壤资源的不合理利用和管理是导致这些问题的重要原因之一。因此,保护土壤资源并促进其持续高效安全利用已成为当前国际社会高度关注的议题。2013年联合国粮农组织大会通过决议将每年12月5日定为世界土壤日,并宣布2015年为"国际土壤年",主题为"健康土壤带来健康生活",提倡对全球土壤资源的保护     

密云水库水体营养状态分析

调研结果显示 ,密云水库的营养特征为浮游藻类响应型。浮游藻类的群落结构是绿藻 (Chlorophyta)—硅藻(Bacillariophyta)型。库区水体TN 0 86mg/L ,TP 0 .0 2 2mg/L ,浮游藻类的细胞密度 4 0 5 2 3× 10 4/L。 4项指标 (Tr、TP、CODmn、chla)的TSIM 值 4 0 1— 4 9 6 ,水体为中营养。但TN、TP和浮游藻类细胞密度增长较快 ,水体向富营养发展的趋势明显。主要制约因素是面源、点源和内源对水体的污染。北京市水资源紧缺 ,密云水库是主要饮用水源地。保护流域生态环境 ,治理污染 ,涵养水源 ,实现水资源的可持续利用已很迫切     

北京城市化进程中的水资源利用区际冲突初探

随着城市化进程的快速推进,北京市对水资源的需求量和对水质要求都相应提高,在流域水资源总量有限的情况下,引起同一流域内上游地区可用水量的减少,同时,也会要求上游地区采取各种措施提高水质保护水平,这在一定程度上限制了上游地区经济发展和人民生活质量的改善,使流域下游城市与上游地区之间产生水资源利用区际冲突.本文在分析北京市水资源供需矛盾的基础上,探讨了基于水质保护和需水量增加的流域水资源利用区际冲突问题,分析认为水资源总量不足、权属不清以及没有完全实行区际补偿机制,是产生水资源利用区际冲突的根本原因.建议协调流域内各地区的经济利益,建立水资源补偿与合作机制,逐步实施水权分配制度,实行流域水资源统一管理,建立流域水资源新型管理体制,同时加快大型调水工程建设和使用,是解决水资源利用区际冲突问题的主要途径.     

程海水生植被现状及其演变趋势

近20年来,程海水生植物种类和群落类型进一步趋于简单化,水生植被覆盖度由24％～75％变为0．2％～85％,分布最大水深虽由4．5m延伸至5．5m,分布面积却由527．8hm2缩减为73．05hm2,资源蕴藏量由4766吨降低至314．53吨。分析认为：程海南部大面积适生生境破坏、水质污染、水体富营养化、不合理放养草鱼是加剧其水生植被衰退的主要原因。提出了恢复南部湿地、削减入湖污染物、禁止投放草鱼、控制水质污染和水体富营养化等保护对策。     

流域水环境管理保护线与控制线及其规划方法

社会经济的发展以及公众环境意识的不断提高,对水质及水环境的要求不断提升,水资源及其环境问题已成为制约我国社会经济可持续发展的瓶颈因素.但在水体保护和管理方面,一直以来缺乏适当的方法或者规范来确定明确的范围与界线,因而难以对水体进行有效的保护和管理.提出流域水环境管理保护线和控制线的概念,与城市蓝线类似,是对流域内江、河、湖、库、渠和湿地等地表水体进行严格保护和控制的地域界线,但在流域水环境综合管理的基础上拓展了其内涵,强调以流域为单元.保护线宽度较小,线内设计植被带,类似于河岸植被缓冲带的概念,对水体及水环境起着缓冲及保护的关键作用;控制线范围较宽,其作用主要在于控制区域内的土地利用及社会经济活动科学有序进行,在社会经济发展的同时不以牺牲水环境为代价.综合考虑流域内生态环境、社会安全、经济发展等因素,结合岸线控制、河岸缓冲带等内容探讨了流域内水环境管理保护线和控制线确定的方法,并以鄱阳湖流域为对象进行了案例研究,取得了较好的结果.表明本文提出的概念和相关规划方法可有效指导流域水环境保护的实践工作,并为各类规划和政策的制定提供科学参考.     

污染对华南植物园水生生态系统的影响

华南植物园水体８０年代前水质较好。进入８０年代后,由于水源受污染、厕所排放和枯枝落叶进入水塘腐解等因素导致水体严重富营养化,水体的透明度为０．４ｍ,ｐＨ值为６．８６,ＤＯ为３．３ｍｇ／Ｌ,ＢＯＤ为１０．０ｍｇ／Ｌ,电导率为１８９．９μｓ／ｃｍ,浮游生物为２５００万个／Ｌ,总Ｐ的质量含量为０．２５ｍｇ／Ｌ,总Ｎ的质量含量为２．０ｍｇ／Ｌ,叶绿素总质量含量为０．３３ｍｇ／Ｌ,水体中高等植物的多样性及其     

基于非点源污染控制的景观格局优化方法与原则

对目前国内外较为常用的基于非点源污染控制的景观格局优化方法及其设计原则进行了系统的评述 ,以促进其推广应用并提高其污染控制效果。还通过分析这些方法在我国的应用前景 ,强调了探索适合我国国情的景观格局优化方法对于控制非点源污染的重要意义。     

湖泊-流域生态系统管理的内容与方法

在流域生态系统管理研究综述的基础上,对湖泊一流域生态系统管理的概念进行了界定,对水环境管理、综合流域管理与流域生态系统管理之间的差异进行了对比分析。确定了生态系统生态学、流域生态学、生态系统健康和流域方法为湖泊．流域生态系统管理的理论基础,生态系统方法和流域分析为其方法学基础。在上述分析的基础上,提出了湖泊．流域生态系统管理的6个主要步骤：研究范围界定、基础信息收集与基本生态学问题的分析和评价、管理目标设定、系统综合、生态系统综合评价、适应性管理;识别出湖泊-流域生态系统管理中的3个关键问题：①生态系统管理中的不确定性和障碍分析;②流域土地利用变化对湖泊水质和生态系统的影响;③流域生态子系统与社会子系统的关联。     

城市化对流域生态水文过程的影响研究综述

了解流域水文过程(水量和水质)是流域综合管理的基础。城市化引起的生态环境问题已成为目前和未来一段相当长的时期内人类社会面临的重大问题。然而,城市化(土地利用/覆被变化、新污染物产生)、水文(降水、入渗、蒸散、径流过程)和生态系统服务(产水服务、调节气候、土壤保持、初级生产力、维持生物多样性等)在不同时空尺度之间的相互作用还存在知识空白。从城市化对流域生态系统结构和功能的影响、城市化对地表能量平衡与水量平衡的影响、城市化对水质和水生生物的影响、以及城市土地利用/覆被变化的大气环境效应等多方面系统总结了城市化影响流域生态水文过程的研究进展。研究发现,城市"热岛"、"干岛"、暴雨径流引起的城市内涝、水污染等环境现象都与生态水文过程密切相关。强调现代城市规划需要遵循生态水文学规律,从全流域生态系统角度认识近年来新出现的不同尺度的城市环境效应。城市最佳管理措施应以流域为单元实施,以调节土地利用/覆被、保护湿地(包括自然与人工湿地)为手段,充分发挥自然生态系统调节功能(如植被蒸散和净化水质)。未来城市生态水文学应围绕"低影响开发"以及"基于自然的解决方案"等城市流域管理措施,在稳定城市小气候、缓解洪涝干旱等极端水文气象灾害风险以及减轻城市水污染等方面开展多尺度综合研究。     

Assessing the role of large herbivores in the structuring and functioning of freshwater and marine angiosperm ecosystems

While large herbivores can have strong impacts on terrestrial ecosystems, much less is known of their role in aquatic systems. We reviewed the literature to determine: 1) which large herbivores (> 10 kg) have a (semi‐)aquatic lifestyle and are important consumers of submerged vascular plants, 2) their impact on submerged plant abundance and species composition, and 3) their ecosystem functions. We grouped herbivores according to diet, habitat selection and movement ecology: 1) Fully aquatic species, either resident or migratory (manatees, dugongs, turtles), 2) Semi‐aquatic species that live both in water and on land, either resident or migratory (swans), 3) Resident semi‐aquatic species that live in water and forage mainly on land (hippopotamuses, beavers, capybara), 4) Resident terrestrial species with relatively large home ranges that frequent aquatic habitats (cervids, water buffalo, lowland tapir). Fully aquatic species and swans have the strongest impact on submerged plant abundance and species composition. They may maintain grazing lawns. Because they sometimes target belowground parts, their activity can result in local collapse of plant beds. Semi‐aquatic species and turtles serve as important aquatic–terrestrial linkages, by transporting nutrients across ecosystem boundaries. Hippopotamuses and beavers are important geomorphological engineers, capable of altering the land and hydrology at landscape scales. Migratory species and terrestrial species with large home ranges are potentially important dispersal vectors of plant propagules and nutrients. Clearly, large aquatic herbivores have strong impacts on associated species and can be critical ecosystem engineers of aquatic systems, with the ability to modify direct and indirect functional pathways in ecosystems. While global populations of large aquatic herbivores are declining, some show remarkable local recoveries with dramatic consequences for the systems they inhabit. A better understanding of these functional roles will help set priorities for the effective management of large aquatic herbivores along with the plant habitats they rely on.     

Ecological and economic analysis of lake eutrophication by nonpoint pollution

Abstract The hypothesis that economic damage due to nonpoint pollution exceeds costs of mitigation can be tested by ecologists, economists, and resource managers working at the spatial scale of watersheds for periods of years to decades. We present a framework for combining ecological and economic information to compare management scenarios for nonpoint pollution. Eutrophication of lakes caused by nonpoint phosphorus pollution, a common environmental problem, is the focus of our approach. Economic advantages of mitigating nonpoint pollution increase as the uncertainty of ecological predictions decreases. Uncertainty is measured by the prediction variance of nonpoint pollution models. A major source of variance in nonpoint pollution predictions is the effect of land use change on phosphorus transport. This variance is often large because calibration data sets do not have sufficiently wide ranges of land use variables. Ecological predictions and the resulting economic assessments could be improved by comparative studies of watersheds with contrasting land uses, and by viewing nonpoint pollution management as a large-scale experiment.     

基于陆地-水生态系统耦合的海河流域水生态功能分区

水生态功能分区是针对水生态系统特征的陆地生态系统划分,是为流域水生态管理提供生态背景和基本单元。陆地-水生态系统的耦合是水生态功能分区的核心,但多停留在个别小流域进行理论探讨,大型流域的实际案例较少。针对海河流域独特的气候、地貌、水文和人类活动特征,提出了水生态功能分区的三级指标体系。一级二级区针对气候、地貌、水文背景进行"自上而下"的分区,三级区针对人类活动对水资源、水环境、生境影响,采用"自下而上"的分区方法。最终,海河流域划分了6个一级区、16个二级区和73个三级区。研究充分体现了"以水定陆、以陆控水"的基本原则,以及"自下而上"和"自上而下"分区方法的优点,结果可为海河流域水生态管理提供科学依据,为水资源空间调配与合理利用、产业结构布局与区域协调等服务。     

水生态保护目标制定的理论与应用

我国目前处于生态环境管理的转型期,尚未形成统领水生生物、生物栖息地、水质与水量等要素的水生态保护体系。在总结相关水生态研究成果的基础上,梳理形成了基于水生态系统时空尺度和状态梯度效应理论的水生态保护目标制定构想与方法,分析了淡水生物完整性对自然地理要素、水环境压力、栖息地质量的响应机制,提出以水生态“功能分区-状态评价-问题诊断-目标预设-可达性评估-目标确定”为主线的水生态保护目标制定技术体系,研发了生物完整性评价、水生态保护目标预设和可达性分析等技术方法。以江苏省常州市为典型水生态功能区应用案例,验证了技术体系的适用性与可行性,取得良好的应用效果。水生态保护目标制定理论和方法方面的研究探索可为全国相关工作提供参考依据。     

An integrated model for assessing the risk of TCE groundwater contamination to human receptors and surface water ecosystems

The practical implementation of the European Water Framework Directive has resulted in an increased focus on the hyporheic zone. In this paper, an integrated model was developed for evaluating the impact of point sources in groundwater on human health and surface water ecosystems. This was accomplished by coupling the system dynamics-based decision support system CARO-PLUS to the aquatic ecosystem model AQUATOX using an analytical volatilization model for the stream. The model was applied to a case study where a trichloroethylene (TCE)-contaminated groundwater plume is discharging to a stream. The TCE source will not be depleted for many decades; however, measured and predicted TCE concentrations in surface water were found to be below human health risk management targets. Volatilization rapidly attenuates TCE concentrations in surface water. Thus, only a 30-m stream reach fails to meet surface water quality criteria. An ecological risk assessment found that the TCE contamination did not impact the stream ecosystem. Uncertainty assessment revealed hydraulic conductivity to be the most important site-specific parameter. These results indicate that contaminant plumes with μg L^?1 concentrations of TCE entering surface water systems may not pose a significant risk.     

Human activities cause distinct dissolved organic matter composition across freshwater ecosystems

Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by the interactions among physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation across freshwater ecosystems differentially affected by human activity. Using optical properties, we described DOM variation across five ecosystem groups of the Laurentian Great Lakes region: large lakes, Kawartha Lakes, Experimental Lakes Area, urban stormwater ponds, and rivers (n = 184 sites). We determined how between ecosystem variation in DOM composition related to watershed size, land use and cover, water quality measures (conductivity, dissolved organic carbon (DOC), nutrient concentration, chlorophyll a), and human population density. The five freshwater ecosystem groups had distinctive DOM composition from each other. These significant differences were not explained completely through differences in watershed size nor spatial autocorrelation. Instead, multivariate partial least squares regression showed that DOM composition was related to differences in human impact across freshwater ecosystems. In particular, urban/developed watersheds with higher human population densities had a unique DOM composition with a clear anthropogenic influence that was distinct from DOM composition in natural land cover and/or agricultural watersheds. This nonagricultural, human developed impact on aquatic DOM was most evident through increased levels of a microbial, humic‐like parallel factor analysis component (C6). Lotic and lentic ecosystems with low human population densities had DOM compositions more typical of clear water to humic‐rich freshwater ecosystems but C6 was only present at trace to background levels. Consequently, humans are strongly altering the quality of DOM in waters nearby or flowing through highly populated areas, which may alter carbon cycles in anthropogenically disturbed ecosystems at broad scales.     

Freeze–thaw processes and intense rainfall: the one-two punch for high sediment and nutrient loads from mid-Atlantic watersheds

Large runoff, sediment, and nutrient exports from watersheds could occur due to individual extreme climate events or a combination of multiple hydrologic and meteorological conditions. Using high-frequency hydrologic, sediment, and turbidity data we show that freeze–thaw episodes followed by intense winter (February) rainstorms can export very high concentrations and loads of suspended sediment and particulate organic carbon (POC) and nitrogen (PN) from mid-Atlantic watersheds in the US. Peak suspended sediment (> 5000 mg L^?1), POC (> 250 mg L^?1) and PN (> 15 mg L^?1) concentrations at our 12 and 79 ha forested watersheds for the February rainfall-runoff events were highest on record and the fluxes were comparable to those measured for tropical storms. Similar responses were observed for turbidity values (> 400 FNU) at larger USGS-monitored watersheds. Much of the sediments and particulate nutrients likely originated from erosion of stream bank sediments and/or channel storage. Currently, there is considerable uncertainty about the contribution of these sources to nonpoint source pollution, particularly, in watersheds with large legacy sediment deposits. Future climate projections indicate increased intensification of storm events and increased variability of winter temperatures. Freeze–thaw cycles coupled with winter rain events could increase erosion and transport of streambank sediments with detrimental consequences for water quality and health of downstream aquatic ecosystems.