Analisis Acoustic Backscattering Dasar Laut di Perairan Pulau Tidung, Kepulauan Seribu

Abstract

Pulau Tidung memiliki potensi besar sebagai daerah tujuan wisata bahari. Perencanaan dan pengembangan pembangunan Pulau Tidung memerlukan pemahaman mengenai kondisi perairan termasuk dasar perairannya. Penelitian ini bertujuan mengukur dan menganalisis nilai volume backscattering strength (SV) dan nilai surface backscattering strength (SS) berbagai tipe substrat dasar perairan di Perairan Pulau Tidung dengan menggunakan instrumen hidroakustik Single Beam Echosounder SIMRAD EK15. Pengambilan data akustik dilakukan dengan pemeruman secara stasioner, data oseanografi dengan menghanyutkan CTD AML Minos-10 dan data sedimen diambil serta dianalisis di laboratorium yang dilakukan oleh Prof. Henry Manik, S.Pi., M.T., Ph D. beserta dengan timnya. Penelitian ini berfokus pada pengolahan data menggunakan software Sonar 5 Pro. Analisis data akan menghasilkan nilai SV yang akan digunakan untuk menghitung nilai SS. Kecepatan suara sebesar 1.541,58 m/s sampai 1.543,03 m/s. Nilai SV tertinggi dari pecahan kerang bercampur rubble yaitu sebesar -9,84 dB, sedangkan nilai terendah dari pasir sangat halus sebesar -19,07 dB sampai -18,08 dB. Nilai SS tertinggi dari pecahan kerang bercampur rubble sebesar -15,92 dB dan terendah dari pasir sangat halus sebesar -25,15 dB sampai -24,15 dB. Perbedaan antara nilai SS yang diperoleh dari jenis sedimen yang sama disebabkan oleh perbedaan ukuran, berat dan juga persentase komposisi fraksi. Hasil analisa yang diperoleh dari hubungan MGS dan SS berupa nilai koefisien korelasi sebesar 0,5555 dikategorikan cukup kuat dan nilai koefisien determinasi sebesar 0,3086 yang artinya 30,86% SS dipengaruhi oleh nilai MGS. Kata kunci: hidroakustik, Pulau Tidung, regresi linier, surface backscattering strength, volume backscattering strength.

Tidung Island has great potential as a marine tourism destination. Planning and developing the development of Tidung Island requires an understanding of the condition of the waters including the bottom of the waters. This study aimed to measure and analyze the volume backscattering strength (SV) and surface backscattering strength (SS) values of various types of bottom water substrates using the hydroacoustic single beam echosounder Simrad EK15. Acoustic data was collected by stationary sounding, oceanographic data by washing away CTD AML Minos-10 and sediment data were collected and analyzed in a laboratory conducted by Prof. Henry Manik, S.Pi., M.T., Ph. D. and his team. This study focuses on data processing using Sonar 5 Pro software. Data analysis will produce an SV value which will be used to calculate the SS value. The highest SV value was obtained from crushed coral mixed with rubble, which was -9.84 dB, while the lowest value was from very fine sand which was -19.07 dB to -18.08 dB. The highest SS values were obtained from crushed coral mixed with rubble of -15.92 dB and the lowest for very fine sand was -25.15 dB to -24.15 dB. The difference between the SS values obtained from the same sediment type is caused by differences in size, weight and also the percentage of fraction composition. The results of the analysis obtained from the relationship between MGS and SS are in the form of a correlation coefficient value of 0.5555 which is categorized as quite strong and a coefficient of determination of 0.3086 which means that 30.86% of SS is influenced by the MGS value. Keywords: hydroacoustic, linear regression, surface backscattering strength, Tidung Island, volume backscattering strength.