Simulation of shoreline change at downcoast area of a breakwater | |
| Author | Pratchya Paksee |
| Call Number | AIT Thesis no.WM-95-07 |
| Subject(s) | Coast changes Breakwaters |
| Note | A Thesis submitted m partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-95-07 |
| Abstract | Simulation of shoreline change has been carried out to study the effect of breakwater to shoreline at upcoast and downcoast area. Study area is breakwater at Cha-um beach, Phetchburi, Thailand. Field wave data at buoy is obtained from National Research Council of Thailand for two years period. Wave characteristics at Cha-um are represented in term of wave height, wave periods and wave direction. Monthly average wave height and wave periods are in range of 0.35- 0.72 m and 2.26-3.87 second while mostly wave direction are propagated from south, southsoutheast and southeast direction. Numerical model of shoreline change is developed using oneline model approach. In shoreline computation, closure depth at sand start movement is approximately equal to 1 m when mean wave height is used as representative of all year wave. After calibration with shoreline change between 1968 and 1980 which is taken from aerial photograph, longshore sediment transport parameters K1 and K2 are equal to 0.44 and 1.6. Verification of computational result are made for two years in 1991 and 1992. It shows good agreement for deposition at upcoast and satisfactory result for erosion at downcoast area. At upcoast shoreline, calculated deposition rate in 30 years is 16.7 m/year while field data show 17.5 m/year. However for longer time periods, this rate is reduced to 6.5 m/year. It will take about 46 years for half breakwater deposition and 169 years for full breakwater deposition with distance of 1200 m. At downcoast shoreline, it is found that calculated erosion rate is -2.3 m/year while field data show -3 .7 m/year. Remedial measures have been tested in numerical model in two cases which construction of offshore breakwaters and beach nourishment. Both methods can reduce erosion at downcoast area. Offshore breakwater provide deposited form for case of one breakwater while erosion at their gap occurs when number of breakwater increases. Beach nourishment of different sand volume can reduce erosion distances compared with the case without remedial measures. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-95-07 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Sutat Weesakul; |
| Examination Committee(s) | Suphat Vongvisessomjai;Kyotoh, Harumichi; |
| Scholarship Donor(s) | Royal Thai Government; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology,1995 |