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471.
海湾综合整治与资源环境优化研究进展 总被引:1,自引:1,他引:0
依据近年来国内外的研究成果,综述了海湾综合整治专项研究的内容、方法,阐述了基于数值模拟技术的海湾综合整治效果预测的研究方法.在深入分析的基础上,就海湾综合整治目前存在的问题和今后的研究工作进行了讨论,并就此提出了几点建议. 相似文献
472.
应用景观生态学方法,结合煤矿区规划环评的特点,从景观功能与稳定性评价入手,建立了三层次的适用于煤矿区规划评价的指标体系。并以晋中煤矿基地——西山矿区为例,进行矿区规划景观功能与稳定性评价的研究。结果表明,在煤矿区规划开发活动中,应加强采煤沉陷区的治理和恢复,注重水土保持和景观破碎化的改善,以减少规划对景观功能和稳定性的破坏。运用本次确定的评价体系进行定量计算的结果与常规的景观定性分析结论基本一致,但该指标体系还需要从区域生态承载力人均化、加强污染物变化情况远期预测和细化地表沉陷引起土地面积损失几个方面加以改进和完善。 相似文献
473.
文章以梧州市某林浆纸一体化原料林建设项目为例,借助3S技术分析原料林基地建设对生态环境的影响,探讨3S技术在生态环境影响评价中的应用。 相似文献
474.
基于3MRA模型的填埋场安全填埋废物污染物阈值评估方法与应用研究 总被引:3,自引:0,他引:3
选取案例填埋场7种目标污染物为研究对象,运用3MRA模型模拟污染物在填埋场周围环境介质中的迁移转化.结果表明,7种目标污染物最低安全填埋阈值大小顺序为:污染物二价镍>苯>镉>铅>六价铬>砷>汞;污染物苯、砷、汞各自的人类和生态受体安全填埋阈值相同,镉和二价镍的人类受体安全填埋阈值高于生态受体,六价铬的生态受体安全填埋阈值高于人类受体,场区地下水的致癌风险和危害商分别为5.06×10-7和2.3×10-1. 相似文献
475.
476.
退牧还草地区生态补偿机制研究 总被引:14,自引:0,他引:14
王欧 《中国人口.资源与环境》2006,16(4):33-38
退牧还草工程作为21世纪初国家启动的一项重大的生态治理工程。在部分地区已取得了初步成效。然而也暴露出了不少问题。尤其是现行的补偿体系不够完善。无法实现农牧民的适度补偿。因此。建立与完善退牧还草项目的补偿体系。对巩固草原地区生态建设成果意义重大。本项研究在构建完整的生态补偿机制分析框架的基础上。通过问卷调查及跟踪访谈等方法。对内蒙古翁牛特旗退牧还草项目的实施进行实证分析。并根据不同类型草场的产量与承载力。遵循“以失定补”的原则。制定了不同类型草场的补偿标准。最后提出建立与完善退牧还草地区生态补偿机制的途径与措施。 相似文献
477.
Carl E. Zipper Braven Beaty Gregory C. Johnson Jess W. Jones Jennifer Lynn Krstolic Brett J.K. Ostby William J. Wolfe Patricia Donovan 《Journal of the American Water Resources Association》2014,50(4):807-819
The Clinch River of southwestern Virginia and northeastern Tennessee is arguably the most important river for freshwater mussel conservation in the United States. This featured collection presents investigations of mussel population status and habitat quality in the Clinch River. Analyses of historic water‐ and sediment‐quality data suggest that water column ammonia and water column and sediment metals, including Cu and Zn, may have contributed historically to declining densities and extirpations of mussels in the river's Virginia sections. These studies also reveal increasing temporal trends for dissolved solids concentrations throughout much of the river's extent. Current mussel abundance patterns do not correspond spatially with physical habitat quality, but they do correspond with specific conductance, dissolved major ions, and water column metals, suggesting these and/or associated constituents as factors contributing to mussel declines. Mussels are sensitive to metals. Native mussels and hatchery‐raised mussels held in cages in situ accumulated metals in their body tissues in river sections where mussels are declining. Organic compound and bed‐sediment contaminant analyses did not reveal spatial correspondences with mussel status metrics, although potentially toxic levels were found. Collectively, these studies identify major ions and metals as water‐ and sediment‐quality concerns for mussel conservation in the Clinch River. 相似文献
478.
Bernard W. Sweeney J. Denis Newbold 《Journal of the American Water Resources Association》2014,50(3):560-584
This literature review addresses how wide a streamside forest buffer needs to be to protect water quality, habitat, and biota for small streams (≤~100 km2 or ~5th order watershed) with a focus on eight functions: (1) subsurface nitrate removal varied inversely with subsurface water flux and for sites with water flux >50 l/m/day (~40% avg base flow to Chesapeake Bay) median removal efficiency was 55% (26‐64%) for buffers <40 m wide and 89% (27‐99%) for buffers >40 m wide; (2) sediment trapping was ~65 and ~85% for a 10‐ and 30‐m buffer, respectively, based on streamside field or experimentally loaded sites; (3) stream channel width was significantly wider when bordered by ~25‐m buffer (relative to no forest) with no additional widening for buffers ≥25 m; (4) channel meandering and bank erosion were lower in forest but more studies are needed to determine the effect of buffer width; (5) temperature remained within 2°C of levels in a fully forested watershed with a buffer ≥20 m but full protection against thermal change requires buffers ≥30 m; (6) large woody debris (LWD) has been poorly studied but we infer a buffer width equal to the height of mature streamside trees (~30 m) can provide natural input levels; (7, 8) macroinvertebrate and fish communities, and their instream habitat, remain near a natural or semi‐natural state when buffered by ≥30 m of forest. Overall, buffers ≥30 m wide are needed to protect the physical, chemical, and biological integrity of small streams. 相似文献
479.
Courtney E. Moore Steven P. Loheide II Christopher S. Lowry Jessica D. Lundquist 《Journal of the American Water Resources Association》2014,50(4):1033-1050
Vegetation in subalpine meadows in the Sierra Nevada Mountains is particularly vulnerable to lowering of groundwater levels because wet meadow vegetation is reliant upon shallow groundwater during the dry summer growing season. These ecosystems are especially vulnerable to channel incision as meadow aquifers are hydrologically connected to tributaries, and many have not yet recovered from previous anthropogenic influences. While instream restoration projects have become a common approach, lack of postrestoration monitoring and communication often result in a trial‐and‐error approach. In this study we demonstrate that preimplementation modeling of possible instream restoration solutions, chosen to raise stream stage and subsequently groundwater levels, is a useful tool for evaluating and comparing potential channel modifications. Modeling allows us to identify strategic locations and specific methods. Results show additional sediment depth and roughness on tributaries along with introduced woody debris (simulated by high roughness) on the Tuolumne River are the most effective means of raising stream stage. Results demonstrate that restoration efforts are most efficient in tributary streams. Managers and planners can more efficiently direct resources while minimizing the potential for negative impacts or failed restoration projects by modeling the possible effects of multiple restoration scenarios before implementation. 相似文献
480.
截至目前,环境中抗生素的行为及其对生态毒性的影响仍被忽视。这一课题的范畴是宽泛的,涉及到广泛的生物体,包括栖居在各种水生生态系统中的微生物,藻类,无脊椎动物和脊椎动物等。改变这种系统中任何一个组成的平衡破坏了整个系统的平衡。在人类和动物医学中,氟喹诺酮的制造和频繁使用引起了对微生物抗生素耐药性流行率增加的高度关注,而且,除此之外,通过各种途径进入环境生态系统的抗生素母体和代谢物化合物的归趋也引起了环境影响关注。相关研究集中在分析环境样品中氟喹诺酮的存留浓度,并且经常使用动物评估模型来测试急性毒性,但是仍然不清楚在水生环境中低水平慢性接触对生命形态的生态毒性影响中起什么作用。本综述的目的是评估氟喹诺酮在动物和人类医学中的使用水平,确定其传播的途径,突出在淡水环境中的生态毒理学影。
精选自Nicol Janecko, Lucie Pokludova, Jana Blahova, Zdenka Svobodova, Ivan Literak. Implications of fluoroquinolone contamination on the fresh water aquatic environment -A review. Environmental Toxicology and Chemistry: Volume 35, Issue 11, pages 2647–2656, November 2016.
DOI: 10.1002/etc.3552
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3552/full 相似文献