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971.
以铜陵市河湖水系为研究区,利用土地利用类型、植被覆盖度、降雨侵蚀力、地形等数据,分别计算了针对总氮、总磷通量的功能连通性指数,对比分析了不同流域及其河湖水系的连通性情况,并提出相应的水文连通调控措施.结果 表明:基于总氮的功能连通性指数的平均值在菜子湖、岱冲湖、连城湖、白荡湖、枫沙湖、陈瑶湖、顺安河和黄浒河分别为0.9...  相似文献   
972.
针对我国城市内河污染日益严重的问题,以巢湖市老城区环城河为研究对象,拟定调水方案,进行调水试验。依据沿河水文水质情况,布设6个实时水质监测点,并将环城河概化为5个河段。应用测得的水文水质数据对各河段不同时间点的含氮污染物负荷进行估算,初步研究了各河段NH3-N、TN负荷量的变化规律。通过对比上下游各河段含氮污染物负荷去除效果,分析调水效果的影响因素,总结个别河段调水效果不佳的原因,提出4条优化意见。并结合实际情况,选取其中可行性较强的1条对其有效性进行实验验证。  相似文献   
973.
针对微污染水水质不稳定,CODMn波动较大的问题,本研究构建了3套中试规模的以"前置生态氧化塘、两级水平潜流湿地和表流湿地为核心、后置沉水植物塘"为工艺的多级人工湿地-塘组合系统(处理水量230 L·d-1,分别命名为S1、S2和S3).在3种进水浓度条件下(原水、稀释2倍和稀释1.3倍后的水体,分别作为S1、S2和S3系统的进水),考察了3套湿地-塘系统各单元对实际微污染河水中CODMn的处理效果,并采用高通量测序等方法解析了S1系统湿地单元微生物群落分布特征.研究结果表明,3套系统的平均出水COD较进水有着非显著的升高,从升高的程度来看,S2>S3>S1.污染浓度相对最高、运行时间最长的S1系统对COD有着更好的净化效果.相较于S2系统,S3系统更高的进水浓度有利于COD去除.S1和S2系统的二级水平潜流湿地较其他单元有着较好的COD去除作用,平均去除率分别为18.60%和26.52%.S3系统的表流湿地较其他单元有着较好的COD去除作用,平均去除率为8.92%.微生物群落分析结果表明,S1系统的一级、二级水平潜流湿地中细菌丰度和多样性沿程提高,两个单元所富集的相同优势菌群包括α-变形菌纲、γ-变形菌纲和拟杆菌纲,与COD降解有关的菌属分别包括unclassified_f__Burkholderiaceae、unclassified_c__Alphaproteobacteria、norank_f__Blastocatellaceae和norank_f__Saprospiraceae、红细菌属.表流湿地中细菌丰富度进一步升高,但生物多样性有所减少,其中蓝菌属和norank_c__Actinobacteria可能与表流湿地出水COD升高有关.本研究为大型河口湿地-塘复合生态系统处理微污染地表水时工作重心由浓度削减向污染物释放控制的转移提供了宝贵的工程经验.  相似文献   
974.
西南国际河流水资源状态及开发中的问题   总被引:2,自引:0,他引:2  
西南国际河流流域地形复杂、海拔高、人口稀少,人均水资源量丰富,出境水量大,水质好,目前开发利用程度低,具有广阔的开发利用前景。但随着我国加入WTO,经济和社会发展融入国际的步伐加快,对国际河流的开发和利用也必然要按照国际法或国际惯例。首先对西南国际河流水资源的自然状态,我国在各自流域中的地位、开发利用状态以及存在的问题进行了论述;然后讨论国际河流开发中应注意的问题和准则;最后,根据可持续发展的原则和各个河流的特点,提出建议:应该充分认识到我国西南国际河流地区生态环境脆弱和社会经济发展水平较低的状态,今后应以水资源保护为主,优先发展航运和旅游业,合理开发水能资源。同时应积极参与国际合作与交流,与相关国家共同开发流域水资源,促进流域经济社会的可持续发展。  相似文献   
975.
We developed a method for determining 11 abused drugs in water and sediment. METH and EPH were the dominant drugs in water and sediment in Beiyunhe River. Abuse drugs in Beiyunhe River were mainly from hospitals and sewage effluents. Abused drugs in the water would not impair the aquatic ecosystem biologically. This study investigated the presence of 11 abused drugs and their metabolites, including amphetamine, methamphetamine (METH), ketamine, ephedrine (EPH), cocaine, benzoylecgonine, methadone, morphine, heroin, codeine, and methcathinone in the surface water and sediment samples of Beiyunhe River, a typical urban river flowing through Beijing, Tianjin, and Hebei provinces in North China. An analytical method of determining these abused drugs and their metabolites in water and sediment was developed and validated prior to sample collection in the study area. Results showed that METH and EPH were predominant in water and sediment samples. The total drug concentrations ranged from 26.6 to 183.0 ng/L in water and from 2.6 to 32.4 ng/g dry weight in sediment, and the drugs mainly originated from hospitals and sewage treatment plants. The average field-based sediment water distribution coefficients of abused drugs were calculated between 149.3 and 1214.0 L/kg and corrected by organic carbon. Quotient method was used to assess the risks. The findings revealed that these drugs and their metabolites at determined concentrations in water samples will not impair the aquatic ecosystem biologically, but their potential harmful effect on the function of the ecosystem and human health should not be overlooked.  相似文献   
976.
Seasonal changes in river water chemistry and in soil atmospheric CO2 concentrations at two depths and drainage water solute composition at two upland peaty podzol sites in north east Scotland were monitored over 12 months. the CO2 concentrations were controlled by changes in soil temperature and moisture status. Highest CO2 concentrations were observed in late summer 1988 when both soil temperatures and the moisture status of the soils were high. Then maximum CO2 concentrations of 4% (v/v) were recorded for one of the sites. No significant correlations between seasonal changes in soil CO2 concentrations and river water solute composition were observed. Nevertheless the field results and laboratory experiments indicated that in upland areas, where soils with acid surface horizons are common, soil CO2 substantially influences river water chemistry at baseflow, increasing the pH and cation concentration of the soil water draining into the river. the results suggest that transfer of carbon as dissolved CO2 in drainage water is a significant pathway for CO2 transfer to the atmosphere.  相似文献   
977.
The contents of 90Sr and 137Cs and the pattern of their redistribution in the soil and plant cover of floodplain ecosystems have been assessed. It is shown that the radionuclide distribution across the floodplain and along the river flow is determined by the formation of a barrier to their migration near the river channel, at which less mobile 137Cs accumulates. The soil and plant cover of the central floodplain are enriched with 90Sr. Differences in radionuclide migration in floodplain soils and their input into plants are determined by the relationship between the processes of their immobilization and migration with soil water.  相似文献   
978.
试验本着农村产业结构调整,退耕还草畜养和绿洲生态农业优化管理的研究宗旨,把甜高粱作为南疆农村产业结构调整和发展生态畜牧业的优良品种在尉犁县进行栽培试验.结果表明在南疆类似尉犁县气候条件的地区,其生育期为130d,每年除收获种子外还可收割一茬牧草,年产鲜草86 400 kg/hm2、收获种子1 770 kg/hm2.  相似文献   
979.
The lower Roanoke River in North Carolina, USA, has been regulated by a series of dams since the 1950s. This river and its floodplain have been identified by The Nature Conservancy, the US Fish and Wildlife Service, and the State of North Carolina as critical resources for the conservation of bottomland hardwoods and other riparian and in-stream biota and communities. Upstream dams are causing extended floods in the growing season for bottomland hardwood forests, threatening their survival. A coalition of stakeholders including public agencies and private organizations is cooperating with the dam managers to establish an active adaptive management program to reduce the negative impacts of flow regulation, especially extended growing season inundation, on these conservation targets. We introduce the lower Roanoke River, describe the regulatory context for negotiating towards an active adaptive management program, present our conservation objective for bottomland hardwoods, and describe investigations in which we successfully employed a series of models to develop testable management hypotheses. We propose adaptive management strategies that we believe will enable the bottomland hardwoods to regenerate and support their associated biota and that are reasonable, flexible, and economically sustainable.  相似文献   
980.
干旱区水环境质量的好坏直接决定着绿洲经济建设的水平.通过对玛纳斯河15年来的水质监测资料的分析、研究,从中寻找出该流域的地表及地下水质变化规律与发展趋势.研究结果表明:玛河径流形成区及山前倾斜平原区水质一直保持在一级未受污染级别;山前倾斜平原区地下水中挥发酚以及氮素含量逐年上升,但总体水质仍然保持在一级未受污染级别的范围.  相似文献   
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