排序方式: 共有23条查询结果,搜索用时 31 毫秒
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海南小海潟湖环境的破坏与治理 总被引:3,自引:2,他引:3
从口门稳定性的角度,分析了三大人为工程(太阳河改道、在通道口修筑北堤和封堵南汊道及约5 km2的潮滩被围垦)所起的作用以及波浪动力对小海口门演变的影响,认为小海潟湖潮汐通道在其演变进程中,由于潮汐弱而波能相对较强,目前仍属波浪作用为主型,依据自己多年的研究工作,首次提出以口门复式断面和通道分汊的方法对小海及该类型潟湖进行治理. 相似文献
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海南小海沉积物中的重金属分布特征及潜在生态风险评价 总被引:3,自引:0,他引:3
对小海沉积物进行采集,测定了沉积物中的Cu、Pb、Cd、Zn、Hg、As重金属的含量,用单因子指数法和Hakanson生态风险指数法评价了沉积物中重金属综合污染效应.研究结果表明:小海湾内沉积物中Cu、Pb、Cd、Zn、Hg、As的平均含量分别为0.20 mg/kg、0.18 mg/kg、0.30 mg/kg、0.22 mg/kg、0.44 mg/kg、0.23 mg/kg.沉积物所监测的重金属中,Hg金属的空间波动程度最高,其他重金属的空间波动程度较低.沉积物质量评价结果表明:小海沉积物中主要的重金属污染因子是As,其重金属影响因子的顺序为As>Hg>Pb>Cr>Zn>Cu>Cd;各种重金属的潜在生态危害系数大小顺序为Hg>As>Cd>Pb>Cu>Cr>Zn;潜在生态风险指数 RI平均值为37.06,属于轻微潜在生态风险. 相似文献
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Gayan Lakendra Gunaratne Norio Tanak Prasanna Amarasekar Tilak Priyadarshan Jagath Manatunge 《环境科学学报(英文版)》2010,22(6):813-819
Groyne system modification is described related to restoration e orts to Koggala lagoon, Sri Lanka.The large-scale unplanned sand
removal at the lagoon mouth shifted the formation of sand bar towards the lagoon and made adverse e ects on its ecosystem. After the
removal of the natural sand bar, groyne system was constructed to avoid sand deposition in the lagoon and to protect the highway bridge
(across the lagoon outlet channel) from the wave attack. The existing groyne system resulted the lagoon mouth being permanently open
to sea which in turn led to many environmental problems. Groyne system modification is proposed in this study to reduce the sea water
intrusion.Water budget and two-dimensional depth averaged hydrodynamic model were developed for understanding the hydrologic
and flow characteristics of the lagoon. Numerical experiments was performed at lagoon mouth area for two cases: (1) existing condition
and (2) proposed rubble mound groyne system condition. Comparison of results was obtained for both cases to describe flow pattern at
lagoon mouth. Results further showed, the width should be reduced to a maximum of 40 m. Proposed mouth width (40 m) pushed the
salting factor towards 0.5 from 0.68. Salting factor reduction with the groyne modification may result a predominant influence of fresh
water which may in turn lead lagoon to a fresh water ecosystem. 相似文献
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