ERS-1 for mapping jetties effects on shoreline change Fig. 5 shows that the erosion occurred in the south of Chendering and north of Chendering with approximately 4 m/month. The sedimentation occurred near to the south jetty with -2.3 m/ month. The lower rate of shoreline change is investigated from aerial photography data during 1970 to 1980. The rate of shoreline change increased to 3.8 m/year during 1996. The maximum peaks of erosion model from quasi-linear model and ERS-1 vector layer are coincided each other. In addition Fig. 6 shows a good correlation between ERS-1 vector layer (1996) with historical vector layers derived from aerial photogrpahy and quasi-linear model with of 0.82 and p less than 0.05. This result indicates a high accuracy of the quasi-linear model for the shoreline detection.  Fig. 5. Shoreline Change Model  Fig. 6. Regression Model of Shoreline Change It can be explained that the mechanism of the shoreline change along the Chendering as: the southerly wave when approached the jetty diffracted and induced strong longshore current at the southerly jetty. This southerly jetty trapped all the sediment transport and deposited beside the jetty. This action caused erosion in the south of Chendering. Inside the Chendering port the current meander and carried the sediment out the port causing erosion inside the port. The sediment carried out from the Chendering deposited along the north jetty. Due to the weak littoral drift the shoreline extends along the north of Chendering exposed to erosion by less than 3 m/month. These results are not similar to study of Stenely et al., [7] and Salleh et al.,[6] . This is because that Stenely et al., (1985) did not consider that diffraction could induce erosion and sedimentation. It obvious that most studies have been along the east coast of Peninsular Malaysia have not applied any numerical model to detect shoreline change due to coastal structures. In spite of that, August represents a southwest monsoon season in which characterized by less wave energy Maged and Mansor [4] in coastal water of Kuala Terengganu, erosion occurred along the Chendering shoreline. This suggests a future study, which includes the modeling of the shoreline change along the Chendering by using the integration of Kapas Island and jetty in shoreline configuration. Conclusion In conclusion, ERS-1 data could be used to investigate the jetty effects on shoreline configuration. This is because that the ERS-1 data can be used to model wave information compared to classical methods over large scale. The shoreline change simulated from ERS-1 data suggested that jetty caused erosion along the coastal water of Chendering. References
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