Kajian dinamika pantai : Studi kasus di Pantai Rening, Jembrana, Bali

Abstract

The objectives of present study were to determine the distribution of sediment associated with shoreline changes and to analyze the beach dynamics in Rening Beach. Sediment samples were taken from seventeen sampling points spread along the beach, and then followed by the lab test using granulometri method to determine the characteristics of sediment. Shoreline change was analyzed using analysis of satellite imagery in 2011, 2014 and 2016, while the sediment transport were analyzed using Hjulstrom graph. Then, Rening Beach dynamics can be analyzed. Sediment test results showed that sediment type in Rening Beach was dominated by sand with diameter of between 0.25-5 mm. The ocean currents movement was dominantly to the west. The results of shoreline change analysis between the years 2011-2016, and Hjulstrom graph analysis showed the same pattern that Rening Beach was eroded. The Rening Beach was high dynamics with subjected to beach erosion in the form of littoral drift due to longshore currents.

Penelitian ini bertujuan untuk mengetahui perubahan garis pantai, transpor sedimen dan dinamika pantai di Pantai Rening. Pengambilan data arus dan sampel sedimen diambil dari tujuh belas titik pengambilan sampel yang tersebar merata di sepanjang perairan Pantai Rening. Sampel sedimen kemudian diujikan di laboratorium menggunakan metode granulometri untuk mengetahui karakteristik sedimen. Perubahan garis pantai dianalisa menggunakan analisis peta citra satelit tahun 2011, 2014 dan 2016, sedangkan pola transpor sedimen dianalisa menggunakan grafik Hjulstrom. Dari hasil analisa perubahan garis pantai dan transpor sedimen, dapat dianalisa dinamika Pantai Rening. Hasil uji sedimen menunjukkan bahwa jenis sedimen didominasi oleh pasir sedang dengan diameter antara 0.25-5 mm. Pergerakan arus dominan mengarah ke arah barat. Hasil analisis perubahan garis pantai antara tahun 2011-2016, dan analisa grafik Hjulstrom menunjukkan pola yang sama bahwa pada Pantai Rening mengalami erosi dan mundurnya garis pantai. Dinamika Pantai Rening cukup tinggi dengan kecenderungan terjadi erosi pantai berupa littoral drift akibat arus sejajar pantai.