Shoreline Change Dynamics using Digital Shoreline Analysis in Cemara Besar Island

Abstract

This paper will describe a study to find out the shoreline changes that occurred on Cemara Besar Island along with the accretion and abrasion. Data taken from the images was obtained through google earth as a result of radiometry and geometry correction from Landsat satellites in the last 5 years. Wind data is obtained from ecmwf interm every season for 5 years. Analysis of shoreline changes was carried out using the DSAS (Digital Shoreline Analysis) method and analyzed by wind and sea wave factors in each season. The results of the analysis obtained LRR and EPR values for 5 years, the extent of changes in island land mass, the value of Hs and Ts from the results of wave forecasting using wind data. To simplify the analysis, Cemara Besar Island is divided into 9 segments based on variations in LRR values. The results show that in general Cemara Besar Island have very high accretion in segments A, B and E with an average of 3.61 m and very high abrasion occurred in segment F with an average of -1.01 m. Abrasion occurs with the greatest speed of change in segment A with an average of 4.64 m/year and the largest accretion rate in segment F with an average of -1.21791 m/year. Analysis of oceanographic factors through wave forecasting shows that in the west and transition I season, waves occur with Hs 1.21 m, greater than the eastern season and transition II season with Hs 0.91 m. wind direction from north dominant direction 377.50 in west season and transition I, and from east direction 67,25 in east season and transition I season. Direction of wind blowing influences wave propagation and direction of wave coming towards shore which affects sediment transport which produces accretion and abrasion on the Cemara Besar Island.

Hydro-Oceanographic Characteristics In Karimunjawa Coastal Waters During The 1st Transitional Season

“…This current condition is closely related to the sediment transport at the tip of Cemara Besar Island. The research (Ramdhan, Yulius, & Putra, 2020) shows a dynamic change in the shoreline at the end of the island. The waters between Cemara Besar and Cemara Kecil Islands have a calm current, not more than 10 cm/s, and various directions.…”

“…Thus, indicated by bathymetry of the sea bad. Referring to the research (Ramdhan, Yulius, & Putra, 2020) said that the slope of the island is gentle in the majority. So that, able to deflect the tidal current flow.…”

Estimation of Longshore Sediment Transport in Cemara Besar Island, Karimun Jawa

“…Sehingga dengan ini dapat diestimasi karakteristik gelombang pecah yang menyebabkan adanya transport sedimen di sepanjang pantai. Kelerengan pantai (slope) diperoleh dari pengukuran lapangan menggunakan GPS geodetic CHC Nav tipe i50 dengan ketelitian vertikal 0.02 m. transek slope berdasarkan kesesuaian lokasi abrasi dan akresi di Cemara Besar, berdasarkan Ramdhan et al (2020). Transek berjumlah 14, dengan masingmasing berjarak 6-10 meter dari garis pantai kea rah laut.…”

“…Berdasarkan riset terdahulu mendapatkan bahwa disepanjang pantai Cemara Besar terjadi fenomena abrasi dan akresi berdasarkan perubahan garis pantai. Namun, hasil penelitiannya tidak menjelaskan proses litoral yang bekerja di sepanjang pantai (Ramdhan et al, 2020). Dengan demikian untuk menambah pustaka daya dukung lingkungan di Pulau Cemara Besar maka diperlukan analisis proses litoral berupa longshore sediment transport.…”

Spatio-Temporal Shorelines Change Model in Totok Bay Southeast Minahasa

“…The world's population is almost about 60 percent inhabiting the coasts, human interest in inhabiting this place results in many problems faced such as changes in shorelines that almost hit all the coasts of the world [1]. Thus, coastal areas play an important role in economic development, namely the transport and tourism industries [2][3][4][5]. Unfortunately, the spatio-temporal variation of the shoreline is very dynamic and is of great concern due to the threat of erosion and accretion [6].…”