||Changes in coastal environment are the balancing process of nature. However, most of the constructions on the coast affect the environment, cause erosion and further impair people’s right of access to the water due to lacking in understanding the coastal changes. In the past decade, the author of this dissertation has worked on coastal protection and restoration for Kaohsiung, including Cijin coastal restoration and Sizihwan landscape improvement etc., and provided new thoughts for the domestic planners dealing with coastal environment. |
Affected by recent coastal development and environmental changes in Kaohsiung, Cijin coast has suffered serious erosion. Besides, drowning accidence often occurs caused by rip currents. In order to preserve this beautiful beach with a time-honored history, Kaohsiung City Government commenced the “Cijin Coastline Protection Project” in 2009, the first domestic coastal restoration project employing offshore submerged breakwaters. The project was successfully completed in July 2013. In this study, numerical tools (GENESIS, MIKE 21) and hydraulic model tests were adopted to investigate littoral drift issue, formulate beach stabilization policy, and evaluate the effects of beach nourishment. The results showed that predominant direction is northward during the prevailing wave season. At Cihou Mountain, wave deflects offshore, and deposits sediment into the navigation channel at the end of southern breakwater for the Kaohsiung First Harbor. Therefore, the best beach stabilization scheme for Cijin coast is to apply offshore submerged breakwaters (or with offshore breakwaters) cooperating with beach nourishment. In this way, the erosion at Cijin can be mitigated, as well as the speed of rip currents, and the safety of all beach users can be insured. As to the evaluation of beach nourishment, the results indicated that it was necessary to integrate the project with beach nourishment, otherwise the native beach sediment in the gap between the submerged break waters would be transported in their lee, thus causing adverse effect to the beach.
Upon the completion of the Cijin Coast Protection Project, the overall coastal environment, including submerged breakwaters, offshore breakwaters, the bathing beach, the coastal landscape trail, and the sea-lookout platform all together expand the recreational space from the land to the seaside by connecting with the existing coastal park. It has also enhanced the opportunities for the tourism industry and accelerated the development of service industry in Cijin area. The work described in this report not only initiates a domestic pioneer project of coastal protection, but also serves as an indicator of significance.