不同疏浚方案下的安海湾整治修复效益评估

Assessment of the expected repair and restoration effects under different dredging plans in Anhai Bay

为改善安海湾的海洋生态环境,本研究尝试采用底泥疏浚、疏浚土回填造地、红树林种植和人工岛建设相结合的方式进行海湾整治修复,并初步设置5种疏浚方案,分别计算其疏浚总量、采砂量、采砂率及疏浚后安海湾纳潮量、库容量的变化.结果表明不同疏浚方案的总疏浚量、采砂量、采砂程度、库容增加量随疏浚深度增加而增大,海湾纳潮增加量受平均最低潮位的影响,疏浚深度超过1.45 m后,各方案的纳潮增加量不变.通过疏浚物的回填可降低海湾整治修复及海洋资源利用成本,减少海洋倾倒二次污染,为其他海湾生态环境整治修复工程提供示范.

To improve the marine ecological environment in Anhai Bay,we combined the actions of dredging,sedi-ments backfilling,mangrove planting and artificial islands constructing to restore the ecological functions.Five dred-ging plans were designed to calculated respectively the volumes of dredging materials,the volume and the rate of sands extracted,storage capacity and tidal flux after the dredging.The results showed that the total dredging vol-ume,sands extraction volume and storage capacity increased with the dredging depth.The increment tidal flux of the bay was depended on the lowest tides by average and it stopped increasing when the dredging depth exceeded 1.45 m.By sediments backfilling,the costs for restoration and sea resource utilization could be reduced with re-sults of dumping reduction.The assessment would be an example for other bay ecological environment restoration project.