KAJIAN KARAKTERISTIK GELOMBANG PECAH DI PANTAI TEMPAT PELELANGAN IKAN (TPI) PULAU BUNYU, KABUPATEN BULUNGAN

Abstract

ABSTRACT: Pulau Bunyu is a district in Bulungan Regency, North Kalimantan Province. TPI (Fish Auction Place) Beach is one of beaches found in Pulau Bunyu. TPI beach is an area frequently visited by many people for recreation. However, people said that a lot of sand has been eroded by the sea water. Thus, it is necessary to have information related to the characteristics of waves by studying the characteristics of breaking waves. Wave forecast was made by the calculation using a deep wave hindcasting method based on the wind data within a period of 10 years from the BMKG Tarakan station to obtain the period and wave height. From the calculation results, the waves at TPI Beach in Pulau Bunyu district were dominated by the eastward waves with the maximum wind speed occurring in March 2020 with H = 2.765 m and T = 6.880 s, Kr = 0.9404 – 1.0023 and Ks = 0.913 – 1.244, Hb = 2.2 m, db = 0.4, and Angle = 17.2°. The dominant wind wave had H = 0.700 m and T = 4.197 s, Kr = 0.8244–1.0545, and Ks = 0.914-1.270, Hb = 0.7 meter, db = 0.2 m, and Angle = 28°. The Average wave had H = 0.720 m and T = 4.391 s, Kr = 0.919-0.9998 and Ks = 0.914-1.27, Hb = 0.74 meter, db = 0.2 m, and Angle = 19°. These were waves damaging the beach because the wave height was more than 1.00 meter. This event only occurred at the maximum wind conditions. Meanwhile, the frequent and average winds, the waves were constructive or not damaging the beach because the wave height was than 1.00 meter.

Keywords: Breaking waves, hindcasting, Pulau Bunyu TPI Beach, wave characteristics.

ABSTRAK: Pulau Bunyu adalah sebuah kecamatan di Kabupaten Bulungan, Provinsi Kalimantan Utara. Pantai TPI (Tempat Pelelangan Ikan) salah satu pantai di Pulau Bunyu yang  terletak di Desa Bunyu Selatan. Pantai TPI merupakan kawasan yang sering di datangi oleh penduduk untuk melakukan rekreasi. Menurut warga banyak pasir-pasir yang tergerus air laut. Maka perlu adanya informasi tentang karakteristik gelombang pada daerah tersebut yang dapat merusak pantai, salah satunya adalah dengan kajian karakteristik gelombang pecah. Peramalan gelombang di lakukan dengan perhitungan menggunakan metode hindcasting gelombang berdasarkan data angin kurun waktu 10 tahun dari stasiun BMKG Tarakan untuk mendapatkan periode dan tinggi gelombang. Dari hasil perhitungan gelombang di Pantai TPI Pulau Bunyu di dominasi oleh gelombang arah Timur dengan kecepatan angin maksimum terjadi pada bulan Maret 2020 dengan H = 2,765 m dan T= 6,880 det, Kr = 0,9404 – 1,0023 dan Ks = 0,913 – 1,244, Hb = 2,2 m, db = 0,4 dan Sudut = 17,2°. Pada gelombang angin dominan dengan H = 0,700 m dan T = 4,197 det, Kr = 0,8244-1,0545 dan Ks = 0,914-1,270 , Hb = 0,7 meter, db = 0,2 m dan Sudut = 28°. Pada Gelombang Rata-Rata dengan H = 0,720 m dan T = 4,391 det, Kr = 0,9190-0,9998 dan Ks = 0,914-1,270 , Hb = 0,74 meter, db = 0,2 m dan Sudut  = 19°. Pada kondisi angin maksimum gelombang ini termasuk gelombang yang merusak pantai karena tinggi gelombang lebih dari 1.00 meter, sedangkan pada kondisi besaran angin yang sering terjadi dan rata-rata, gelombang tidak merusak pantai.

Kata Kunci : Gelombang Pecah, hindcasting, karateristik gelombang, Pantai TPI Pulau Bunyu