| 英文摘要 |
The objectives of this project include using the supplemental investigation data, strengthening the sediment pollution transfer model, applying model building principles of sediment transfer model to perform preliminary simulation, and processing research to put forward the sediment quality management strategy.
The project had collected the water quality and sediment investigation data of Agongdian Reservoir and Agongdian Creek as a reference. According to the requirement of the project, it had been planned to process supplement investigation and to strengthen the verification of the sediment transfer model. Processing the scenario simulations is the next step to predict the diversification of the sediment under presumed condition. The results mentioned above are integrated to suggest the management plan of Agongdian Reservoir and Agongdian Creek.
According to the supplementary investigation results of the project, only the heavy metal nickel and arsenic in the bottom sediment of Agongdian Reservoir exceeded the lower limit of sediment quality. Comparing with the supplementary investigation results of the sloping land in the catchment area, the sediment in the reservoir area was mainly from the erosion of catchment soil. Part of the concentrations of chromium, copper, zinc, nickel and arsenic in Agongdian Creek were higher than the upper limit, and mercury was higher than the lower limit. The verifications of the sediment transfer model for these six heavy metals and scenario simulation of various pollution were processed. The results of scenario simulation showed that these two scenario, "excavation of sediment in the whole river section and control of pollution sources in tributary" and "setting of in-situ capping in the river section with heavy metal higher than the upper limit and control of pollution sources in tributary", can control the concentration of heavy metals in sediment to be under the lower limit. It was also shown that, in addition to the necessary management and reduction of heavy metals in sediment of pollutant sources, it was necessary to coordinate with the reduction and control of the external pollution sources in order to avoid the significant accumulation of heavy metal concentrations in the sediments.
In addition, for the sediment quality management strategy in Taiwan, foreign sediment management strategies were collected and analysis of foreign experience of site remediation, to provide domestic reference. Domestic management strategies of sediment was suggested and the applicable management strategy was proposed according to the characteristics of the Agandian River Basin. For water bodies that have not processed supplementary investigation of sediment, the project will develop a sediment transfer model for existing water quality data to assist in the definition of highly polluted areas. The simulation results could be reference for subsequent operations and studies.
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