Karakteristik Ukuran Butir dan Lingkungan Pengendapan Sedimen Dasar Perairan di Teluk Pangpang – Banyuwangi

Muhammad Yusrizal Makbul Setiawan, Dr. Bachtiar Wahyu Mutaqin, S.Kel., M.Sc.

2025 | Skripsi | GEOGRAFI DAN ILMU LINGKUNGAN

Teluk Pangpang yang terletak di wilayah Banyuwangi merupakan wilayah kepesisiran yang memiliki karakteristik unik. Secara geografis, teluk ini berbatasan langsung dengan perairan Selat Bali dan juga menjadi muara bagi dua aliran sungai, yakni Kali Mati (Kali Pangpang) dan Kali Setail, yang membawa material sedimen ke perairan Teluk Pangpang. Penelitian dilakukan untuk mengidentifikasi distribusi ukuran butir sedimen di wilayah perairan Teluk Pangpang guna memahami variasi spasialnya serta untuk menganalisis mekanisme sedimentasi dan lingkungan pengendapan di Teluk Pangpang. Penelitian dilakukan menggunakan metode analisis granulometri terhadap 32 sampel sedimen. Analisis granulometri pada lokasi penelitian menunjukkan bahwa nilai ukuran butir (mean) berkisar antara pasir halus hingga pasir kasar (0,5–3,1 ?). Nilai sortasi berada dalam rentang poorly sorted – medium sorted (0,30–1,50 ?). Nilai skewness berkisar antara very coarse skewed hingga near symmetrical (?0,30 hingga 0,025 ?). Sementara itu, nilai kurtosis menunjukkan rentang dari platykurtic hingga leptokurtic (0,6–1,5 ?). Berdasarkan hasil analisis diketahui bahwa area dekat muara sungai didominasi oleh sedimen halus (komposisi fraksi dominan hingga 99,8% pasir), mengindikasikan pengaruh signifikan dari input fluvial. Sebaliknya, area yang dekat dengan Tanjung Sembulungan cenderung didominasi oleh sedimen kasar (komposisi fraksi dominan hingga 55,8% kerikil). Berdasarkan Linear Discriminant Analysis (LDA) yang dikembangkan oleh Sahu (1964) dapat diklasifikasikan bahwa lingkungan pengendapan Teluk Pangpang bersifat dinamis, dipengaruhi oleh proses fluvial dari muara sungai, arus pasang surut dari laut terbuka, dan kondisi geomorfologi sekitar seperti perbukitan karst yang dapat menjadi sumber sedimen.

Pangpang Bay, located in the Banyuwangi region, is a coastal area with unique characteristics. Geographically, this bay directly borders the Bali Strait waters and also serves as the estuary for two rivers, Kali Mati (Kali Pangpang) and Kali Setail, which carry sedimentary material into the waters of Pangpang Bay. The research was conducted to identify the distribution of sediment grain size in the waters of Pangpang Bay to understand its spatial variation, and to analyze the sedimentation mechanisms and depositional environment in Pangpang Bay. The research was carried out using the granulometric analysis method on 32 sediment samples. Granulometric analysis at the research location showed that the mean grain size values ranged from fine sand to coarse sand (0.5–3.1 ?). The sorting values were in the range of poorly sorted – medium sorted (0.30–1.50 ?). The skewness values ranged from very coarse skewed to fine near symmetrical (-0.30 to 0.025 ?). Meanwhile, the kurtosis values showed a range from platykurtic to leptokurtic (0.6–1,5 ?). Based on the analysis results, it is known that areas near the river mouths are dominated by fine sediments (dominant fraction composition up to 99.8% sand), indicating a significant influence of fluvial input. Conversely, areas near Tanjung Sembulungan tend to be dominated by coarse sediments (dominant fraction composition up to 55.8% gravel). Based on the Linear Discriminant Analysis (LDA) developed by Sahu (1964), it can be classified that the depositional environment of Pangpang Bay is dynamic, influenced by fluvial processes from the river mouths, tidal currents from the open sea, and surrounding geomorphological conditions such as karst hills that can be a source of sediment.

Kata Kunci : sedimentasi, ukuran butir, lingkungan pengendapan, Teluk Pangpang