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521.
I developed a fish-based index of biotic integrity (IBI) to assess environmental quality in intermittent headwater streams in Wisconsin, USA. Backpack electrofishing and habitat surveys were conducted four times on 102 small (watershed area 1.7–41.5 km2), cool or warmwater (maximum daily mean water temperature ≥22 C), headwater streams in spring and late summer/fall 2000 and 2001. Despite seasonal and annual changes in stream flow and habitat volume, there were few significant temporal trends in fish attributes. Analysis of 36 least-impacted streams indicated that fish were too scarce to calculate an IBI at stations with watershed areas less than 4 km2 or at stations with watershed areas from 4–10 km2 if stream gradient exceeded 10 m/km (1% slope). For streams with sufficient fish, potential fish attributes (metrics) were not related to watershed size or gradient. Seven metrics distinguished among streams with low, agricultural, and urban human impacts: numbers of native, minnow (Cyprinidae), headwater-specialist, and intolerant (to environmental degradation) species; catches of all fish excluding species tolerant of environmental degradation and of brook stickleback (Culaea inconstans) per 100 m stream length; and percentage of total individuals with deformities, eroded fins, lesions, or tumors. These metrics were used in the final IBI, which ranged from 0 (worst) to 100 (best). The IBI accurately assessed the environmental quality of 16 randomly chosen streams not used in index development. Temporal variation in IBI scores in the absence of changes in environmental quality was not related to season, year, or type of human impact and was similar in magnitude to variation reported for other IBI's.  相似文献   
522.
通过对广元市生态市的建设现状、指导思想、奋斗目标、建设路径进行深入分析,提出建设生态强市的可行性措施,并从法制、组织、资金、技术方面提供保障。  相似文献   
523.
Indicators are commonly used as tools to identify and highlight socio‐economic and ecological trends and to assess progress towards sustainability. Different quality criteria can be considered for indicators. This paper focuses on the timeliness of indicators used in the evaluation of sustainable development strategies. The analysis is based on indicators included in four assessment reports of the sustainable development strategy of the European Union and three assessment reports of the national strategy of Finland. Furthermore, a web‐based national level indicator portal is analysed. The results show that the timeliness of indicators has generally not improved during the past decade and that indicators used in strategy evaluations have a time lag of approximately two years. It is suggested that more attention should be given to efforts to improve the timeliness of indicators in order to increase the effectiveness of the evaluations. More generally, it is suggested that greater emphasis should be put on the empirical research on actual use of indicators.  相似文献   
524.
Tai Lake (Ch: Taihu) has attracted international attention forcyanobacteria blooms. However, the drivers of cultural eutrophication, especially long-term socio-economic indicators have been little researched. The results of research demonstrate how socio-economic development affected quality of water and how it has been improved by anthropogenic activities. This study described variability in indicators of water quality in Tai Lakeand investigated thedrivers. Significant relationships existed between concentrations of annual mean total nitrogen (TN), total phosphorous (TP), chemical oxygen demand (COD) and biological oxygen demand (BOD), and population, per capital gross domestic production (GDP) and sewage discharge (p?<?0.05). However, mechanisms causing change varied among TN, TP, COD and BOD. Before 2000, the main contributors to increases in concentrations of TN were human population, GDP and volumes of domestic sewage discharges. After 2000, discharges of industrial sewage become the primary contributor. After 1998, the regressions of annual mean TN, TP and COD on per capital GDP, population and domestic sewage discharge were reversed compared to the former period. Since 1999, an apparent inverted U-shaped relationship between environmental pollution and economic development has developed, which indicated that actions taken by governments have markedly improved quality of water in Tai Lake. The statistical relationship between BOD and per capital GDP didn’t conform to the Kuznet curve. The U-shaped Kuznet curve may offer hope for the future that with significant environmental investments a high GDP can be reached and maintained without degradation of the environment, especially through appropriate management of industrial sewage discharge.  相似文献   
525.
以武汉中心城区的东沙湖流域为研究对象,以7项下垫面及3项降雨因子为影响因子,以18项河湖水环境因子为响应变量,基于冗余分析研究多尺度下两者之间的关系.结果表明:在所研究的10项影响因子中,硬质铺装面积率和河网水面率是东沙湖流域城市河湖水环境的主要影响因子,贡献率达0.703和0.652,城市道路面积率则是3000m及以外缓冲区尺度下的主要影响因子,贡献率达0.796,降雨的空间分布不是主要影响因子,贡献率低于0.371;影响因子对水环境影响的尺度效应与排水管网的有无和水文汇水单元尺度的大小密切相关;东沙湖流域的河湖水污染可归因于以硬质铺装为代表的不透水面上的面源污染和经由排水管网运移排放的点源污染,河网水面率则是改善水环境的关键因素.  相似文献   
526.
白洋淀污染的主成分分析   总被引:2,自引:0,他引:2  
在上游多种污染物排放的影响下,白洋淀的污染呈现了富营养化和沼泽化等多种表象。文章以白洋淀为研究对象,采用基于因子分析的主成分分析方法,将白洋淀水质监测数据概括为5个主成分,即:富营养化特征指标、有机物污染指标、藻类生物量指标、生物生长环境指标、水体酸碱度指标。经分析得出:富营养化污染最严重,有机污染次之。文章进一步分析讨论了各主成分的内涵和湖泊的污染净化机理,为白洋淀水体污染的科学治理提供依据。  相似文献   
527.
以区(县)为评价单元,采用野生动物丰富度、野生维管束植物丰富度、生态系统类型多样性、物种特有性、外来物种入侵度、受威胁物种丰富度等评价指标,应用归一化处理方法,对成渝经济区148个区(县)的生物多样性进行了评价,以阐明区域生物多样性空间分布规律. 归一化处理时修正了野生维管束植物丰富度、野生动物丰富度、物种特有性、受威胁物种丰富度4个指标的最大值. 结果表明:成渝经济区中12个区(县)的生物多样性等级为高,71个区(县)为中,55个区(县)为一般,10个区(县)为低. 生物多样性较丰富的区域主要包括大巴山区、渝东南武陵山区、渝南金佛山、四面山、三峡库区、龙门山、川西南山地,而生物多样性较低的地区主要分布在成都平原、盆中丘陵平坝、渝西方山丘陵、川东平行岭谷等区域. 评价结果表明成渝经济区生物多样性的空间分异特征明显.   相似文献   
528.
中国CO2排放总量控制区域分解方案研究   总被引:5,自引:4,他引:5  
探讨CO2排放总量区域分解的方法.借鉴国际上针对国家之间的分解原则和方法,提出中国省际之间的分解的公平性、可行性和效率性三大原则;确定了排放水平、经济水平、工业能源利用水平、非化石能源利用水平4大影响因子;提出了人均排放量、人均GDP、工业增加值能耗、工业增加值能耗变化趋势、非化石能源占一次能源消费比例5个指标,构建了...  相似文献   
529.
苯并(a)芘致毒的鱼的分子生态毒理学指标研究   总被引:10,自引:1,他引:10       下载免费PDF全文
通过测定典型的多环芳烃类物质苯并(a)芘(BaP)致毒后鱼体内几种重要分子生态毒理学指标的变化,来反映苯并(a)芘致毒对鱼体的影响.结果表明,肝脏ATPase活性降低,GST活性升高,DNA加合物相对标记水平(RAL)也增大,而EROD活性没有明显改变.这说明苯并(a)芘致毒对鱼体正常生命活动产生了重大影响,并具有潜在的致癌性.  相似文献   
530.
尿液、头发、指(趾)甲高铊汞砷是铊矿区污染标志   总被引:8,自引:0,他引:8       下载免费PDF全文
铊矿区村民尿液、头发和指(趾)甲中铊汞砷的含量高是矿区和村民受铊汞砷污染的标志,也是判别汞铊病的标志根据村民尿液中铊含量高低初步得出区别不同程度汞铊病患者的标准TL>1000×10-9、100×10-9-1000×10-9和<100×10-9分别为重汞铊病患者、轻汞铊病患者和非汞铊病者。人体和生物体中TL、Hg、As含量高低与矿区岩矿石、土壤和水体中TI、Hg、As的背景含量密切相关  相似文献   
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