共查询到20条相似文献，搜索用时 15 毫秒
1.
Several recent studies have demonstrated that a functional approach (i.e. analysis of traits indicating species ecological functions) can be successfully used for river biomonitoring. To date this approach has only been applied in temperate rivers, even though it could notably contribute toward the development of an environmental assessment system in developing countries in other climatic zones. Using a multivariate approach (Fuzzy Correspondence Analysis—FCA), we analysed functional invertebrate community characteristics (described by 40 categories of seven biological traits mostly at the family level) at 66 stream sites from neotropical Bolivia with different level of anthropogenic disturbance. We were able to separate the sites on the first FCA axis (F1) (ANOVA test) following the predefined environmental quality classes based on the observed impact. Moreover, the F1 axis scores were significantly related to scores obtained using an independent macroinvertebrate multi‐metric index previously developed to assess streams biotic condition in the same biogeographical region. The F1 axis, which thus represents a gradient of anthropogenic impacts, was significantly correlated to 30 of the 40 studied trait categories. Our results (i) clearly confirm the possible use of functional traits for water quality assessment in neotropical streams, and (ii) provides support to the River Habitat Templet hypothesis since habitat disturbances produced predictable functional changes in macroinvertebrate assemblages. Finally, this study supports the potential worldwide applicability of the species‐trait approach as a biomonitoring tool for stream integrity assessment. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
2.
突发重金属水污染事故环境风险评价模型研究 总被引：1，自引：0，他引：1
为降低我国重金属突发水污染事故发生频率、减轻事故危害,针对目前突发水污染事故环境风险评价缺乏系统性研究的现状,构建了基于蒙特卡洛模拟法的突发水污染事故环境风险评价模型,提出了一套计算突发水污染事故环境风险的方法。该模型由突发水污染事故概率分析模型、重金属迁移转化分相模型、突发水污染事故损失评估模型耦合而成。应用该模型对佛山市的环境风险进行了评价,结果表明:计算时间段为固定值时,重大风险值和特大风险值之和为8%;计算时间段为区间值时,重大风险值和特大风险值之和为21%,说明该地区的环境风险已经十分严峻。 相似文献
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The effects of piscicides on aquatic invertebrates are often studied after one treatment, even though piscicides may be repeatedly applied within river management. Here we investigate the impacts of repeated piscidie treatment on riverine benthic invertebrates. The River Ogna, Norway, was treated with rotenone three times over a 16‐month period. The two first treatments caused temporary density reduction of a few rotenone sensitive benthic invertebrate taxa. Effects of the third treatment were variable with some taxa unaffected while all Plecoptera, were locally extinct. The toxic effect of rotenone increases with water temperature and high water temperature (20 °C) combined with high rotenone concentration was probably the main reason why the benthic community in the third treatment was more negatively affected than during the two previous treatments (4 and 8 °C). Eight months after the treatment benthic densities had not reached pre‐treatment levels, but most taxa had recolonized the treated area within a year. Our data suggest that the severe effects of the third treatment were not influenced by the two former ones. This implies that the timing of piscicide treatment has a greater impact on the benthic invertebrate community than the number of treatments. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
4.
底栖动物类群位于腐食食物链的关键一环,在水生态系统中扮演重要角色,其群落组成可以表征河道的健康状况。根据2016年冬季、2017年夏季两个季度对涡河（安徽段）的两次底栖动物的数据采集,对底栖动物群落的时空分布进行分析,同时采用多样性指数对河道开展分段健康评价。结果表明：涡河流域共发现底栖动物3门17属种,冬季以节肢动物和环节动物为主,夏季各物种相对平均。底栖动物的种类数群随季节变化较为明显,两次采样共发现17个属种,两个季节中种类最多的均为节肢动物。涡河（安徽段）干流底栖动物主要表现出生物多样性低、种类分布不均匀、不同河段差异性大等特点,整体来说尚需加强保护。 相似文献
5.
Patrick D. Armitage 《河流研究与利用》2006,22(9):947-966
Cow Green dam is situated in Northern England on the River Tees in a region with high average wind speeds (24 km h?1), low average annual temperatures (circa 5°C) and average rainfall of 1800 mm. The River Tees was impounded by the Cow Green dam in 1970 and early studies revealed significant changes arising from flow regulation. This study compares macroinvertebrate communities in 2004 with those recorded in the first 5 years after impoundment in the Tees and in the unregulated Maize Beck. Nineteen of the 31 common taxa in the regulated sites declined in abundance by a factor of 5 or more. These included Hydra sp., Ancylus fluviatilis, Naididae, Heptageniidae, Leuctridae and Brachycentrus subnubilus. Some taxa, Lymnaea peregra, Ephemerella ignita, Hydroptila sp. increased in numbers, and others Hydropsychidae and Gammarus pulex declined at sites nearest the dam but increased downstream. In Maize Beck there were fewer changes. The changes in faunal communities in the Tees were evident from multivariate analyses where the Tees sites sampled in 2004 were separated from those sampled in the period 1972–1975, as a result of abundance changes in common taxa and the appearance of taxa not previously recorded. Maize Beck in contrast was characterized by few changes in abundance and no new taxa and samples from all years grouped together. The results suggest that the Tees communities have changed since 1975 and are still possibly undergoing change, although without evidence from intervening years this cannot be proved. A narrower range of environmental conditions and increased flow stability have led to a dynamically fragile community (indicated by observed changes in community diversity and abundance) which is very susceptible to perturbations because it has developed in their absence. Periphyton and reservoir plankton play an important role in structuring the faunal composition by creating an environment where biotic interactions are more likely. Increased interaction between components of the faunal community may account for the observed changes since 1975 in the regulated sites in contrast to the situation in the unregulated Maize Beck where there has been little change in faunal community between the original study and the 2004 survey. An unregulated natural flow regime continues to dominate the Maize Beck environment and the variable and unpredictable conditions have resulted in a dynamically robust faunal community. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
6.
A long history of human alterations has affected the hydrology, physical habitat and water quality of most large river ecosystems. For more than a century, the Illinois River Waterway has been subject to channelization, damming, dredging, agricultural runoff and industrial and municipal effluents. This study evaluates how subsequent improvements in water quality have influenced long‐term changes in fish assemblages (1983–2010). We used five metrics to characterize the changes in fish assemblages. These metrics depicted shifts in the abundance and biomass of predatory and native fishes and species richness. Random forests (RF) and multiple linear regressions (MLRs) were used to relate the fish metrics to individual water quality and weather variables, with weather primarily used to account for inter‐annual variation. Model performances varied spatially and among fish metrics (0 ≤ pseudo‐R2 ≤ 0.73 for RF; 0.10 ≤ adjR2 ≤ 0.88 for MLR), but dissolved oxygen, un‐ionized ammonia and water clarity were often the best predictors. As the distance downstream of major pollutant sources increased, water quality became less important for explaining the changes in fish metrics and weather more important. These results indicate that water quality improvement largely accounts for fish assemblage recovery in the river system, although within some reaches we examined, weather had substantial compounding effects. The results could be used to prioritize water quality variables for long‐term monitoring and aid in predicting fish assemblage responses to future changes in water quality and climate. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
南通市河流底泥重金属污染及潜在生态风险评价 总被引：3，自引：0，他引：3
通过对南通市区5条主要河道柱状底泥样品重金属元素质量比的实验分析,探讨河道重金属污染的分布特征,并进行潜在生态风险评价。结果表明:①各重金属元素质量比均超过土壤背景值,污染较重,其中Hg污染最为严重;②重金属污染在垂直分布上分为未受干扰、正常沉积的\"表层高、底层低\"和受清淤治理措施影响的非正常沉积的\"表层低、底层高\"两种分布格局,在水平分布上具有\"城市中间河流高、外围河流低\"和\"中上游河段高、下游河段低\"的分布特征;③从重金属污染的潜在生态风险看,濠河和法伦寺河潜在生态风险强,姚港河生态风险中等,任港河和南川河生态风险轻微。各重金属元素对生态风险的影响程度大小依次为:HgCuZnCrPb。 相似文献
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湖南洞庭湖水系重金属健康风险评价 总被引：9，自引：0，他引：9
为了掌握洞庭湖水系重金属健康风险状况,采用美国环境保护署推荐的水环境健康风险评价模型,对洞庭湖水系重金属通过饮用水途径引起的健康风险进行评价。结果表明：重金属总健康风险在2．27×10-5-1．004×10-4a-1之间,平均为4．87×10-5a-1,未超过关国环境保护署推荐的最大可接受风险水平1×10-4a-1;重金属健康风险从大到小的顺序为：As、Cd、Pb、Cu、Zn,湘江、资水、沅江、洞庭湖、澧水,丰水期、枯水期;As为主要风险污染物;1988年以来,洞庭湖水系“四水”重金属健康风险均呈增加趋势,其中湘江和资水分别增加了13．34和5．07倍,因此,加强洞庭湖流域特别是湘江和资水重金属的污染治理是降低洞庭湖水系重金属健康风险的有效途径。 相似文献
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为揭示石臼湖表层沉积物营养盐和重金属的污染特征,于2018年2月采集表层沉积物,分析了石臼湖营养盐和重金属的含量、空间分布特征。结果表明:全湖有机质、TP和TN的平均质量比分别为30.25 mg/kg、585 mg/kg和776 mg/kg,TP为无污染风险级别,有机质和TN处于低污染风险级别;重金属Cr、Ni、Cu、Zn、As、Cd、Hg和Pb平均质量比分别为94.92 mg/kg、41.25 mg/kg、38.42 mg/kg、124.33 mg/kg、16.48 mg/kg、0.17 mg/kg、0.05 mg/kg和35.92 mg/kg,均超过了江苏省的土壤重金属背景值,Hg和Cd污染相对较重,全湖为中等危害等级;在空间分布上,东部区域的采样点8、9营养盐质量比较高,重金属污染较重。 相似文献
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对北江25个采样点的大型底栖无脊椎动物进行采样调查,并根据大型底栖无脊椎动物的群落结构特征对水质进行生物评价。研究中共采集到大型底栖无脊椎动物46属,分别隶属于15目31科,其中水生昆虫30属,占65.22%;软体动物8属,占17.39%;环节动物6属,占13.04%;甲壳动物2属,占4.35%。出现频率最高的3个种属分别为多足摇蚊属(Polypedilum)、巴蛭属(Barbronia)以及苏氏尾鳃蚓(Branchiurasowerbyi)。应用Shannon-Wiener多样性指数、Margalef多样性指数、Pielou均匀度指数、生物学污染指数BPI(biotic pollution index)、BI(biotic index)、FBI(family biotic index)、Goodnight-Whitley修正指数(GBI)7种生物指数对北江水质进行综合评价。结果表明:与20世纪80年代的评价结果相比,北江的大型底栖无脊椎动物在种类和数量等多方面均发生了较大的变化,生物多样性减少,耐污种所占比例增加,水质理化参数恶化;7种生物指数的评价结果存在一定的差异,部分指数之间存在较高的相关性,FBI指数和BPI指数的准确性和科学性更强,适用于北江水质的生物评价。在25个采样点中,6个采样点水质综合评价等级为较差或极差,16个采样点水质评价等级为一般,3个采样点水质等级为良好,整体水质属于一般的水平。人类活动对河流的水质状况造成了一定的影响。从水质生物学的角度衡量,北江水质整体呈现下降趋势。 相似文献
12.
Flow intermittence occurs in an increasing number of streams, due to climate change, local land‐use alteration and water abstraction. In particular, droughts represent a new element in Alpine river regimes, and their ecological consequences are poorly explored. We here used artificial streams to investigate the resilience of macroinvertebrates to drought in Alpine streams based on the presence of pools (i.e., refuges) and drift (i.e., recolonization). Three flumes were selected: 1 with permanent flowing water (Control), whereas the other 2 (Drift+Pools, Only Drift) were subjected to 2 consecutive drought‐rewetting phases. Moreover, to better monitor the recolonization pattern by drift, quantitative samples of drifting taxa were collected using an additional flume (Incoming Drift). The effects of droughts on benthic invertebrate communities and their recovery were assessed in terms of composition, structure, diversity, and stability. Droughts dramatically reduced the taxa richness, especially with regard to the most sensitive and specialized macroinvertebrates, such as Ephemeroptera, Plecoptera, and Trichoptera taxa. Macroinvertebrate assemblages of the flumes that experienced drying phases were dominated by few generalist taxa and showed a higher degree of dissimilarity. Overall, no significant differences were observed in relation to the presence of pools, suggesting a limited role of this habitat in the recovery process. This finding suggests that in shallow and fast‐flowing Alpine lotic ecosystems the drift rather than pool availability represents the main driver of the macroinvertebrate resilience to droughts and provides insights into factors that can facilitate the recovery of aquatic communities after droughts. 相似文献
13.
为探究长江中下游底泥重金属污染状况,对长江中下游主干河流及湖泊的27个断面的底泥进行采集并测定镉、铅、铬、铜、锌、砷和汞的浓度。运用潜在生态风险指数法对重金属污染进行评价,并采用相关分析和主成分分析对重金属的污染来源进行分析。结果表明:Hg、Cd、Pb、Cr、Cu、Zn和As的含量分别为0.010～0.55 mg/kg、0.016～0.17 mg/kg、13.04～110.03 mg/kg、42.03～121.03 mg/kg、21.70～75.10 mg/kg、48.01～750.01 mg/kg和6.03～82.95 mg/kg。重金属浓度较高的地方位于较为发达的城市(武汉和南京)、采矿业发达的地区(安庆、大通和芜湖)、港口城市(城陵矶)以及湖泊(鄱阳湖和东洞庭湖)。由潜在生态风险评价可知,7种重金属污染程度的大小顺序为:HgAs PbCdCuCrZn。相关分析和主成分分析结果表明Pb、Cd、Zn、Cu、Hg和Cr主要来源于煤炭燃烧、农业活动及生活污水,As主要来源于采矿业和航运业。长江中下游及湖泊底泥所有点位的Pb、Cu、Cr、Zn和Cd均处于轻微潜在生态风险状态,As和Hg在部分点位具有较高潜在生态风险。结合所有重金属元素来说,长江中下游以及湖泊底泥的潜在生态风险水平较低。 相似文献
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Samuel Kibichii William A. Shivoga Mucai Muchiri Scott N. Miller 《Lakes & Reservoirs: Research and Management》2007,12(2):107-117
A study was conducted in the upper reaches of the River Njoro watershed to test the impacts of changing land‐use patterns, from predominantly forest to pasture and agriculture, on benthic macroinvertebrate communities. Stream sampling sites were chosen to correspond to the main offstream land uses, including forests, grazing, small‐scale agriculture, and intensive agriculture. Physicochemical variables were measured at each sampling site, and from collected water samples. Sampled macroinvertebrates were identified, and taxon diversity, richness, evenness and dominance were estimated for each site. Higher mean temperatures were recorded at the grazed and cultivated sites, compared to the forested sites. Higher ammonia concentrations were characteristic of the grazed parts of the watershed, while higher mean total phosphorus and total nitrogen concentrations were observed at the intensively cultivated sites. Baetis and Simulidae composed 65% by number of all the invertebrates collected. They dominated the benthos of the cultivated sections of the watershed, where they formed up to 75% of the observed invertebrate numbers. However, higher mean diversities, richness and evenness were recorded at forested sites, with a few taxa (notably Lepidostoma hirtum, Potamon sp., Leptophlebia sp. and Helodidae) being restricted to these unpolluted reaches, although many other taxa were common to all sites. Our findings suggest that a change from forestry to agriculture and grazing land uses have affected the physicochemical environment of the River Njoro, leading to a reduction in the diversity and evenness of benthic macroinvertebrates. 相似文献
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In the 1970s, Forest Service and academic researchers clearcut the forest in Watershed 7 in the Coweeta Basin to observe how far the perturbation would move the ecosystem and how quickly the ecosystem would return to its predisturbance state. Our long‐term observations demonstrated that this view of resistance and resilience was too simplistic. Forest disturbance triggered a chain of ecological dynamics that are still evolving after 40 years. Short‐term pulses in dissolved inorganic nitrogen (DIN) (3 years) and streamflows (4 years) were followed by several years in which the system appeared to be returning to predisturbance conditions. Then however, changes in forest composition triggered a regime change in DIN dynamics from biological to hydrological control as well as persistent high stream DIN levels mediated by climatic conditions. These forest composition changes also led to later reductions in streamflow. These long‐term observations of streamflows, stream DIN concentrations, stream DIN exports, and stand composition have substantially advanced our understanding of forest ecosystem dynamics; and they demonstrate the value of long‐term observational data in revealing ecosystem complexities and surprises, generating new hypotheses, and motivating mechanistic research. Shorter observational records from this experiment would have produced incomplete or erroneous inference. WIREs Water 2018, 5:e1273. doi: 10.1002/wat2.1273 This article is categorized under:
- Science of Water > Hydrological Processes
- Science of Water > Water Quality
- Water and Life > Nature of Freshwater Ecosystems
16.
为揭示沙颍河沉积物中氮及重金属的分布和污染特征,于2015年6—9月采集了沙颍河干支流主要站点的表层沉积物及上覆水样品,分析了其中氮的赋存形态和重金属的分布,探讨了水体-沉积物氮的转化机制及重金属的来源。结果表明:沙颍河表层沉积物中NO-3-N、NH+4-N、ON(有机氮)和TN的质量比分别为21.47~53.60 mg/kg、1.702 3~3.066 1 mg/kg、1 050~2 390 mg/kg和1 071~2 488 mg/kg,ON占TN的97.17%以上;表层沉积物中Cd、Cu、Zn和As质量比分别为1.583~3.533 mg/kg、21.98~64.60 mg/kg、148.5~165.5 mg/kg和1.527~2.416 mg/kg。Pearson相关性分析表明:表层沉积物中氮主要存在于有机物中,表层沉积物释放NH+4-N已经成为影响沙颍河水体NH+4-N浓度的一个重要因素;沙颍河大部分站点的表层沉积物有机指数和ON分别处于Ⅱ、Ⅳ级,有机碳污染较轻,ON污染严重;潜在生态评价中重金属Cd已经达到了很强-极强的污染程度,其余重金属则处于轻微污染水平;重金属潜在生态风险指数IR显示沙颍河表层沉积物重金属潜在风险已经到了很强-极强的水平,其中Cd对IR的贡献达97.22%。 相似文献
17.
缺资料地区水体突发重金属污染的快速预警 总被引：1，自引：0，他引：1
针对缺资料地区水体突发性重金属污染事件,开展快速预警研究,可以快速预测重金属到达下游水域敏感点的时间和影响程度及范围,以降低突发事件带来的危害。通过地形概化、水力学特征参数快速设置、特征污染物参数选取、模型参数自动校正,建立了缺资料地区水体突发重金属污染事件的快速预警方法,并应用于甘肃突发锑污染事件。将预测值与实测值进行相关性分析,R~2在95%以上,表明该方法可对甘肃锑污染事件发生后污染物到达下游敏感点的时间、浓度变化过程与影响范围进行很好的预测,为事故的风险预警及应急决策提供了依据。 相似文献
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A. Di Sabatino G. Cristiano D. Di Sanza P. Lombardo C. Giansante R. Caprioli P. Vignini F. P. Miccoli B. Cicolani 《河流研究与利用》2016,32(6):1242-1251
The ecological knowledge of large rivers is still scarce or highly fragmented mainly because of complex, laborious and expensive procedures to collect informative samples from the benthic biota. Standard sampling protocols for macroinvertebrates were mainly developed and calibrated for wadeable streams, while a number of heterogeneous non‐standard sampling procedures are available for large rivers. We propose the new, easy‐to‐build and cost‐effective leaf‐nets (LN) method to quantitatively sample benthic invertebrates in non‐wadeable waterways. The LN method uses Phragmites australis leaves as substrate and combines the characteristics of the leaf‐bags and the Hester–Dendy (HD) multiplates methods. We compared the effectiveness of the LN and HD methods in a near‐pristine and in an impacted stream‐reach (downstream an aquaculture plant) of a non‐wadeable second‐order stream of Central Apennines (Italy). Twenty‐five of the 34 cumulatively collected macroinvertebrate taxa were common to both methods, while seven taxa were found only on LN and two only on HD. Taxonomic richness and total macroinvertebrate abundance were higher for LN assemblages. Number of Ephemeroptera, Plecoptera and Trichoptera taxa (EPT) also tended to be higher on LN. Assemblage composition was different on LN and HD. Both methods documented a significant decrease in EPT taxa and a concomitant increase in the total abundance of more pollution‐tolerant taxa in the impacted stream‐reach, but the LN method was more sensitive to impact‐associated changes in macroinvertebrate assemblage structure. In contrast to the hardboard plates of HD, the assembled leaves of the LN may act as a direct or indirect food source and may better mimic the texture and composition of more heterogeneous natural substrates thus favouring the migration–colonization process from both bottom and littoral benthic invertebrates. The sampling efficiency, cost effectiveness and simplicity warrant the routine use of the new LN method in large‐river ecological assessment. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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防控日益严重的水土重金属污染之我见 总被引：3，自引：0，他引：3
傅国伟 《水利水电科技进展》2012,32(1):8-12
当前我国水土重金属污染严重。1996年颁布的GB8978—1996《污水综合排放标准》仍然是现行执法的依据,它明确规定排放的污染物按其性质分为两类,\"汞、镉、铬、砷、铅、镍、铍、银\"8种重金属为第一类污染物,要求不分行业和污水排放方式,也不分受纳水体的功能类别,一律在车间或车间处理设施排出口取样,必须满足最高允许排放浓度标准的规定。它完全不同于一般常规污染物可利用水环境容量,实行总量达标控制原则。这体现了对持久蓄积性污染物实行封闭零排放的原则精神。但目前从水质的监测、评价到污染物的削减控制过程中,存在着一系列背离和混淆两类污染物排放标准和控制要求的问题。防治重金属污染的任务十分艰巨,它涉及许多行业、部门和学科专业。为扭转当前我国水土重金属严重污染的局面,首先应从端正环保系统的技术路线开始;在重金属污染防治中,防要大于治、先于治;当前最紧迫的是从源头控制污染源的继续超量排放,而监控源头必先端正技术路线。 相似文献