Perubahan garis pantai Tanjung Berikat, Pulau Bangka Periode 1992 - 2000

Abstract

The offshore wave regime of Tanjung Berikat beach, in the West coast of Bangka was presented based on the analysis the availability of a dense set of the ERS (European Remote Sensing) 1/2 wind measurements at particular offshore location. The coastlines was divided into several segments represented by local orientation of the coastline. For each of these segments, the breaker wave height, depth and angle of breaker wave and longshore sediment transport were calculated. A linear regression fitting was made based on the total wave regime, to obtain the relation between the peak period, Tp and wave height, Hmo: To 3,2188Hmo +1,8932 Waves approach from directions 0100-055° N, 0550-100° N, 1000-145° N, 145°-180° N, 2810-325° N and 3250-010° N, but most frequent from 2810-325° Ν. The smallest wave height was 0,06 m from directional sector N100-055° in winter and largest 2,8 m from N145°-180° in summer. Incoming waves from the directional sector N281-325° account for most of the winter wave regime duration, about 52%. Such sector was predominantly associated to waves with mean wave height 0,84 m. Also about 28% of the summer wave regime duration corresponds to incoming waves from the directional sector N281-325°, which is mostly associated to waves with mean wave height 0,63 m. The results obtained in this study allowed to estimate the net drift for the periode 1992-2000, the annual variations of the littoral drift to obtain 25 years return periode and rate of accretion and erosion. For the periode 1992-2000, the shoreline showed an accretion at some segments with maximum rate of 6,15 m/year and an erosion at others with maximum rate of 5,16 m/year. For 25 years return periode, shoreline was predicted to be accreted at some segments with maximum rate of 8,8 m/year and eroded at others with maximum rate of 8,4 m/year.