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1.
针对天津市景观河道底泥重金属污染进行了调研,分析了各采样点Zn、Cr、Pb、Cu、Cd 5种重金属的污染情况,采用美国NOAA标准对底泥重金属污染进行生物安全性评估和模糊综合评价,以及采用地积累指数法(排除背景值的影响)对重金属的富集程度进行了评价。结果显示:除子牙河外,天津市景观河道重金属污染都比较严重;重金属Zn、Cu、Cd对河道底泥污染的贡献较大,而Pb、Cr对河道底泥污染的贡献较小;城市工业化和开发是造成河道重金属污染的一个重要原因;"城市水环境改善与水源保护示范工程研究"的工程示范对河道水体改善作用有明显的效果,建议政府大力推广。  相似文献   

2.
With a variety of ecosystem services, river ecosystem plays an important role in the process of human society development. On the other hand, health condition of most aquatic ecosystems is seriously threatened by human activities. Restoring and maintaining a healthy ecosystem has already become a vital goal of river management. As a basis of river management, river health assessment is therefore particularly important. Based on indices of physics, chemistry and aquatic organisms, this research tried to establish a comprehensive evaluation system of aquatic ecological health suitable for the situation of Shaying River Basin. The system included 6 factors including riparian zone, river morphology, nutrients, oxygen balance, periphyton and benthic macroinvertebrates, which were defined into 19 indices reflecting the aquatic ecological health from different aspects. The assessment results indicated that the health condition of overall basin was normal, varying among different parts of the region, with Shahe River, Lihe River and Beiru River in the upper part sub-healthy, and Jialu River in the same part sub-sick. The middle region was generally in normal or sub-sick level; the health condition of the lower part was comparatively better due to a good condition. Within the indices, the nutrients and benthic macroinvertebrates were the major constraining factors to the health condition of Shaying River Basin for their poor health condition. The health conditions showed significant differences among the rivers (P < 0.01), with Jialu River being the worst. The result indicated that the aquatic ecological health of Shaying River Basin is affected by many factors, with urban and industrial sewage being the main ones, And that different protective measures should be employed for rivers of different conditions. The result can provide theoretical basis for the ecological restoration of Shaying River Basin and reasonable exploitation and conservation of the water resource of the whole Huaihe River Basin.  相似文献   

3.
Rehabilitating China's Largest Inland River   总被引:1,自引:0,他引:1  
Li Y  Chen Y  Zhang Y  Xia Y 《Conservation biology》2009,23(3):531-536
Abstract:  Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica , which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20–45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources.  相似文献   

4.
于2009年5月(枯水期)、8月(丰水期)、11月(平水期)对天津地区蓟运河、潮白新河、永定新河、金钟河、北塘排污河、黑猪河、海河、大沽排污河、独流减河、青静黄排水渠、子牙新河和北排水河12条主要河流的水质进行监测,并对监测数据进行主成分分析,构建水质评价指标体系,采用水质标识指数进行水质评价。结果表明,主成分分析与水质标识指数相结合的评价方法客观可靠。从时间分布来看,枯水期水质最差,58.3%的河流为劣Ⅴ类水质,部分河流已经黑臭,8月水质较好。从综合水质标识指数来看,海河以南河流污染较为严重。该地区河流NH3-N污染最为严重,其次是BOD5、CODMn和TP,属于有机型及富营养化污染。  相似文献   

5.
2012年4月,在上海市河网采集表层水和沉积物样品各53个,测定其As含量,并采用潜在生态风险指数法对沉积物As的污染状况进行了评价。研究结果表明,上海市河网表层水和沉积物中As的含量分别为0.47~8.84μg·L-1和3.72~12.65μg·g-1,其中表层水中As的浓度处于中国地表水环境质量标准Ⅰ类水平,沉积物中As的浓度有15个样点超过了上海市土壤背景值,但均低于欧盟标准推荐值;表层水中As的浓度与pH呈显著正相关,说明pH值影响河水中As的迁移和转化;沉积物中As的浓度与总有机碳含量呈显著性正相关,说明沉积物中的As主要与总有机碳结合在一起;潜在生态风险评价结果显示,上海市河网沉积物中的As属于低生态风险。  相似文献   

6.
Previous studies on river health evaluation mainly focused on characterizations at a river-corridor scale and ignored the complex interactions between the river ecosystem and other components of the river basin. Based on the consideration of the interactions among rivers, associated river basin and habitats, an assessment framework with multi-scale indicators was developed. An index system divided among these three scales to characterize the health of river ecosystems in China’s Liao River Basin was established. Set pair analysis was applied to integrate the multi-scale indicators and determine the health classes. The evaluation results indicated that the rivers in the western and eastern zones of the Liao River were classified as sick, and rivers in the main stream of the Liao and Huntai rivers were classified as unhealthy. An excessive level of disturbances, such as large pollution loads and dense construction of water conservation projects within the river basin, were the main causes of the river health deterioration.  相似文献   

7.
廖静秋  文航  苏玉  曹晓峰  黄艺 《生态环境》2012,(7):1277-1284
流域水生态系统具有物质循环、能量流动、群落代谢等服务功能,由于人类活动干扰等因素,水生态系统受到破坏,服务功能的发挥受到抑制。太子河作为中国七大水系之一的辽河支流,其水生态系统健康状况同样由于社会、自然等胁迫驱动力原因受到影响。提出了一套流域水生态系统生境安全识别方法,并以太子河次流域本溪段为案例对方法的可行性进行研讨。采用水文、河道、河岸带和水质4个生境安全指标,分别对研究区的5个评价单元水生态系统生境进行安全评估,做出问题识别,找出水生态系统处于不同健康状态的原因,并确定优先修复项目,便于流域管理。通过研究得到观音阁水库坝区没有优先修复项目,小夹河区、老官砬子-观音阁水库坝区、大峪沟入河口-老官砬子区、兴安市界-大峪沟入河口区优先修复项目分别为河道、河道和河岸带、河道、水质,生境安全识别方法具有一定的可行性。  相似文献   

8.
利用海南省水文局提供的1960—2000年水文资料,对近40年来海南省三大河下游水体的含沙量特征及影响因素进行了分析。结果表明,南渡江、昌化江和万泉河下游水体4—11月份的含沙量一般都较大,而1、2、3、12月份的含沙量都很小,夏秋两季的含沙量明显高于冬春两季,这也跟三大河下游地区的不同月份和季节性平均降雨量分布规律基本相一致,说明降雨在一定程度上决定着三大河流域的土壤侵蚀状况。从年平均含沙量来看,昌化江的含沙量整体明显高于南渡江和万泉河,这可能是昌化江流域原始森林的破坏引起水土流失等自然灾害向下游输送泥沙的结果。  相似文献   

9.
• The source of DOM in surface water and sediment is inconsistent. • The DOC content changes differently in surface water and sediment. • The content of DOC in the surface water is lower than that in the sediment. • The DOM in the surface water had higher photodegradation potentials than sediment. Dissolved organic matter (DOM) in rivers is a critical regulator of the cycling and toxicity of pollutants and the behavior of DOM is a key indicator for the health of the environment. We investigated the sources and characteristics of DOM in surface water and sediment samples of the Wei River, China. Dissolved organic carbon (DOC) concentration and ultraviolet absorbance at 254 nm (UV254) increased in the surface water and were decreased in the sediment downstream, indicating that the source of DOM in the water differed from the sediment. Parallel factor (PARAFAC) analysis of the excitation-emission matrices (EEM) revealed the presence of terrestrial humus-like, microbial humus-like and tryptophan-like proteins in the surface water, whereas the sediment contained UVA humic-like, UVC humic-like and fulvic-like in the sediment. The DOM in the surface water and sediment were mainly derived from microbial metabolic activity and the surrounding soil. Surface water DOM displayed greater photodegradation potential than sediment DOM. PARAFAC analysis indicated that the terrestrial humic-like substance in the water and the fulvic-like component in the sediment decomposed more rapidly. These data describe the characteristics of DOM in the Wei River and are crucial to understanding the fluctuations in environmental patterns.  相似文献   

10.
以北京市3条具有不同功能的代表性河流(清河:纳污排洪;京密引水渠:供水水源;小月河:景观用水)作为研究对象,分析测定了33个水质指标,采用内梅罗指数法与大型蚤急性毒性测试法对3条河流的水质与毒性状况进行了评价,同时运用主成分分析法对毒性产生的原因和影响水质的因素进行了初步探讨.结果表明,1)3条河流已受到不同程度的污染,水质和毒性状况均不容乐观.作为纳污排洪的清河大部分采样点水质较差,生物毒性极高;作为景观用水的小月河水质一般,具有一定的生物毒性;作为供水水源的京密引水渠水质一般,但毒性较低.2)水样生物毒性与Cl-、Ca、K、Li、Mn、Na、Cr、Ni等指标有关;内梅罗水质指数与NO2-、Cl-、K、Na、Ni等指标有关.3)某些指标(如NO2-)超标会对水质分级产生较大影响,但对生物毒性贡献不大,而低浓度的重金属,不会对水质分级产生贡献,却会对生物的生理活动产生影响,综合化学指标和毒性指标共同评价水质更为合理.  相似文献   

11.
北江流域抗生素污染水平和来源初探   总被引:1,自引:0,他引:1  
北江是发源于湖南(武水)和江西(浈水),汇于广东韶关,流经广东全境并入海的三大河流之一。为了解整个北江抗生素污染情况,共设置44个采样点,并采集了河水及部分沉积物样品,较全面地分析了各样品中12种典型抗生素含量并初步探究了其污染来源。研究发现,包括北江源头在内的全河段均有抗生素的检出,5类抗生素在表层水和沉积物中的平均浓度分别为77.8 ng·L~(-1)和3.6 ng·g~(-1)。其中,大环内酯类污染最为严重,其含量范围为11.7~114.6 ng·L~(-1)和0~435.3 ng·g~(-1),远高于其他类抗生素。表层水中磺胺类的磺胺甲恶唑和氯霉素类的检出率达100%,其中以磺胺甲恶唑(14.7 ng·L~(-1))和阿奇霉素(25.0 ng·L~(-1))为主,而沉积物中以阿奇霉素(35.9 ng·g~(-1))、氧氟沙星(5.4 ng·g~(-1))和四环素(3.3 ng·g~(-1))为主。由于流域污染源种类和数量不同,各抗生素在北江中的分布也存在差异。表层水中抗生素含量水平表现为下游高于上中游,在沉积物中则主要集中于中、下游之间河段。这反映了人类活动强度对北江抗生素污染的直接影响。  相似文献   

12.
Fluvial processes such as flooding and sediment deposition play a crucial role in structuring riparian plant communities. In rivers throughout the world, these processes have been altered by channelization and other anthropogenic stresses. Yet despite increasing awareness of the need to restore natural flow regimes for the preservation of riparian biodiversity, few studies have examined the effects of river restoration on riparian ecosystems. In this study, we examined the effects of restoration in the Ume River system, northern Sweden, where tributaries were channelized to facilitate timber floating in the 19th and early 20th centuries. Restoration at these sites involved the use of heavy machinery to replace instream boulders and remove floatway structures that had previously lined stream banks and cut off secondary channels. We compared riparian plant communities along channelized stream reaches with those along reaches that had been restored 3-10 years prior to observation. Species richness and evenness were significantly increased at restored sites, as were floodplain inundation frequencies. These findings demonstrate how river restoration and associated changes in fluvial disturbance regimes can enhance riparian biodiversity. Given that riparian ecosystems tend to support a disproportionate share of regional species pools, these findings have potentially broad implications for biodiversity conservation at regional or landscape scales.  相似文献   

13.
鄱阳湖沉积物中磷吸附释放特性及影响因素研究   总被引:3,自引:0,他引:3  
沉积物是氮磷营养盐的主要蓄积库,它不仅是外来污染物的归宿地,同时其自身营养盐的释放也可对水环境产生重大影响。针对鄱阳湖存在的沉积物磷释放问题,关键环境因子对基质磷吸附的影响规律进行了探讨。通过控制在不同环境因素条件下,上覆水中磷的变化规律探讨,阐明磷在上覆水-底泥界面迁移转化的规律和环境因素对迁移转化过程的影响。研究结果表明,吸附初始阶段,两者含量相差较大,起始吸附速率很高;随着反应时间的推进,两者含量差随之减小;当吸附时间达到30 min时,此时上覆水的平衡质量浓度为8.648 mg·L^-1,两者含量达成平衡。由磷的吸附等温试验同样可看出,随着平衡质量浓度逐渐增加,土壤吸磷量刚开始增加较快,随后增加趋势逐渐减缓直至磷饱和。pH越小,上覆水质量浓度越低,沉积物对磷的吸附作用越强;pH越大,上覆水中TP质量浓度越大,强碱条件下,TP吸收量剧减。在好氧条件下,沉积物对磷的吸附远远高于厌氧条件下沉积物的吸附。好氧条件下,反应在4 h内,沉积物对磷的吸附速率最高,随后吸附量很小直至逐渐饱和。厌氧条件下,吸附作用不明显;当反应时间达到24 h后,上覆水磷质量浓度保持不变,此时沉积物磷吸附达到饱和。高溶解氧水平对于控制底泥向上覆水体释放磷,维持水体较低总磷是必要的。温度为30℃,20℃和5℃3种条件下,当反应24 h后,三者均达到吸附平衡。因此,当上覆水的磷质量浓度较低时,高温条件下基质的磷释放速度会高于低温条件下的磷释放速度。研究结果旨在为正确认识、合理评估环境因素对湖泊水体磷的影响提供更为充分恰当的试验依据和理论解释。  相似文献   

14.
The Yarlung Tsangbo (YT) is a large river running across southern Tibet and has significant effects on its lower reaches, the Ganges–Brahmaputra Basin. In order to investigate the geochemical features of the YT, 18 surface sediment samples were collected; ten trace element concentrations were measured for bulk sediments and two fine grain size fractions. Meanwhile, basic physicochemical parameters and element concentrations of river water were also analyzed. Results indicated that the river water was alkaline (pH 8.42) and that dissolved oxygen was mainly controlled by river water temperature. Some elements (e.g., Zn and Ni) showed close negative relationship to mean grain size of the sediments. Concentrations of most heavy metals, except As of the YT bulk sediments, were similar to those of Upper Crustal Concentration and its lower reaches, indicating almost no anthropogenic impact. Arsenic of the YT sediments was derived fundamentally from the parent rocks of the YT Basin and was far higher than that of its lower reaches. This indicates that relatively small amounts of As from the study area were transported down to the Brahmaputra River under present, relatively dry climatic conditions. However, more YT sediments might have been transported to its low reaches during the Holocene due to the wet climate, giving high As concentration in Holocene sediments of the Ganges–Brahmaputra Basin. Thus, As transported by the YT may produce important influence on the Ganges–Brahmaputra Basin and contribute to its high As concentration in groundwater.  相似文献   

15.
非点源污染目前已经成为影响水体环境的重要污染。微生物源示踪技术(microbial source tracking,MST)是解决非点源污染的一项新技术,它可以确定污染的宿主来源。肠球菌esp基因和多瘤病毒JCV可以作为检测水体中人源粪便污染的分子标记,其灵敏度和特异性都很高。为分析五大流域水源地是否受到人源粪便的污染,对辽河、海河、淮河、长江和黄河五大流域典型水源地水样进行采集和检测,选取人源粪便特异病原微生物肠球菌的esp基因和多瘤病毒JCV建立了相应的MST分子检测方法。结果表明,五大流域的典型水源地采样点均有可能受到了人源粪便的污染,可为当地相关部门提供技术支持和数据参考。  相似文献   

16.
典型城市黑臭河道水体生物毒性研究   总被引:3,自引:0,他引:3  
以黑臭为特征的城市内河污染近来受到关注,检测和分析污染河流水质的生物毒性对水质标识和生态评价十分必要。本研究逐月检测了温州市九山外河(JS River)和山下河(SX River)两条典型黑臭河道水样对斑马鱼、发光细菌和热带爪蟾胚胎的毒性效应。结果显示,黑臭河道水体对斑马鱼、发光细菌(青海弧菌Vibrio Qinghaiensis Q67)和爪蟾胚胎均具有毒性效应。以斑马鱼死亡率和发光细菌相对抑光率表征的水质综合毒性较一致,且以发光细菌更为敏感。爪蟾胚胎致畸实验主要通过存活率和畸形率来表征水体的毒性。3类生物监测均显示SX水体毒性明显高于JS整体毒性,这与两条河黑臭程度相一致。通过发光细菌检测水体综合毒性的分析,显示SX和JS水体毒性在5月-8月的夏季较高,冬春季节较低,表明黑臭河道水质毒性季节性变化与水体温度(T)和溶解氧(DO)值关系密切。本研究结果可为污染水体生物毒性检测和黑臭水体综合评价及后续治理提供依据。  相似文献   

17.
塔里木河下游生态输水过程中荒漠河岸林活力恢复监测   总被引:4,自引:0,他引:4  
根据近5年来对塔里木河下游荒漠河岸林植被的监测数据,分析了生态输水后植物活力的恢复状况.结果显示:应急生态输水增加了塔里木河下游的生物多样性,使原本面临死亡的荒漠河岸植被重新复活,而且不同程度上促进了胡杨群落的自然更新;在近河道50 m的范围内均出现了少量的胡杨、柽柳实生苗,并且在离河道150 m的范围内已经有相当数量的胡杨次生苗,在离河道400 m范围内大约有25%的胡杨均有不同程度的基部新枝萌蘖.通过生态输水后地下水位的逐步抬升,河道两岸的低阶地发育着一定面积的草甸植被,形成了由胡杨、柽柳和草本植物所组成的干旱区非地带性河岸稀疏植被群落,说明应急生态输水对于胡杨为建群种的荒漠河岸林植被的恢复和自然更新产生了积极的影响.  相似文献   

18.
太湖流域水源地多氯联苯分布特征与污染水平   总被引:1,自引:0,他引:1  
为系统了解太湖流域主要水源地多氯联苯(PCBs)的污染现状,于2012年3月和6月分别采集水相、悬浮颗粒物和沉积物样品,并利用气相色谱-质谱联用仪(GC-MS)对PCBs的浓度进行了分析。结果表明,3月水相、悬浮颗粒物和沉积物中均未检测出PCBs类物质。6月水相中PCBs质量浓度在ND~1.04 ng·L~(-1)之间,平均值为0.57 ng·L~(-1),悬浮颗粒物和沉积物中PCBs质量浓度分别在0.96~2.72 ng·g-1和0.47~1.29 ng·g-1之间。Aroclor 1016和Aroclor 1260在3种介质中均有检出,且Aroclor1016浓度均为最高。与国内外研究相比较,太湖流域主要水源地PCBs污染水平较低。水相中PCBs浓度水平低于我国地表水环境质量标准;悬浮颗粒物和沉积物中PCBs浓度水平均低于加拿大保护水生环境沉积物化学品风险评价标准的LEL值,说明各样点PCBs对底栖动物无毒性影响。  相似文献   

19.
The internal nutrient load from bottom sediment to the water column of a Louisiana Barataria Basin lake (Lake Cataouatche) receiving diverted Mississippi River water was determined. Dissolved reactive phosphorus (DRP), ammonium (NH4-N) and nitrate (NO3-N) flux from sediment to water column were measured. The DRP flux averaged-0.22 mg m-2 d-1 under aerobic water column conditions, as compared with that 3.29 mg m-2 d-1 under anaerobic conditions. The average NH4-N released under anaerobic conditions (1.42 mg m-2 d-1) was significantly greater than rates under aerobic conditions (-0.02 mg m-2 d-1), indicating a strong relationship between nutrient flux and oxygen availability in the water column. The average NO3-N flux was 2.13 mg m-2 d-1 under aerobic conditions as compared with-0.24 mg m-2 d-1 under anaerobic conditions in the sediment-water column. When the water column maintained under anaerobic conditions was switched to aerobic conditions, the DRP, NH4-N, and NO3-N concentrations in overlying water decreased rapidly over a short period of time. The mean annual internal DRP and NH4-N load from the sediment to the overlying water was estimated to be 69.26 and 29.9 tonnes (Mg) yr-1 respectively, which represents a significant portion of the total nutrient load to the Lake. Results demonstrate that the internal flux of nutrients from sediments can contribute a significant portion of the total nutrient load to the water column and should be considered in decisions on impact of nutrient in diverted Mississippi River on water quality of Barataria Basin.  相似文献   

20.
Research on community characteristics of riparian herbs is an important scientific basis of riparian vegetation rehabilitation. This study aimed to investigate the species diversity and quantitative characteristics of riparian herbs in Liaohe River Conservation Area and its tributaries. Herbaceous communities were investigated by sample line method. Group average clustering analysis and detrended correspondence analysis (DCA) were used to find the major environmental factors affecting the distribution pattern of riparian herbaceous communities. The result showed altogether 154 herbaceous species, belonging to 40 families and 96 genera. The riparian herbaceous species diversity was found to be correlated to river slope, sinuosity and stream order, being lower in rivers of mountain area than in rivers of plain area, and higher in tributaries than in Liaohe River Conservation Area. Clustering analysis classified the herbaceous communities into 23 types, being dominated by hygrophytes including communities of Echinochloa crusgalli, Oenanthe javanica, Polygonum hydropiper, Murdannia keisak, Artemisia selengensis, Scirpus triqueter, Heleocharis soloniensis, Pycreus sanguinolentus, Cyperus fuscus, Phragmites australis, Polygonum amphibium, Carex diandra + Artemisia selengensis and Carex diandra + Rorippa islandica. Correlation analysis between DCA ordination axes and environmental factors showed that the altitude, river slope, sinuosity and stream level were the major environmental factors affecting the distribution pattern of herbaceous communities in the riparian zone of Liaohe River Conservation Area and its tributaries. The results of CCA showed that the contribution ratio of stream level was the highest, followed by altitude and slope, with sinuosity the last. The results suggested that riparian herbaceous characteristics are affected by the comprehensive force of altitude, river slope, sinuosity and stream order, and that Calamagrostis epigeios, Triarrhena sacchariflora and Phragmites australis are suitable species for riparian vegetation rehabilitation.  相似文献   

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