<![CDATA[Mandeh Bay is a semi-enclosed water area that there are two main estuaries, Mandeh and Nyalo River estuary. Sedimentation issue has been gotten worse due to the massive development in coastal area. This study aims to determine the sediment accumulation within Mandeh bay and its distribution patterns. The measurement of sedimentation rate applied in the Mandeh and Nyalo Estuaries. Oceanography parameters (tides and currents) recorded for 30 days measurement. The thickness of sediment accumulation was predicted by applying single beam echosounder dual frequency. The calculation of sediment volume was done using frustum formula grid 10 x10 meters. Flow model approach was also simulated to depict the distribution pattern of sediment. The thickness of sediment accumulation categorized into five spatial categories that are 0-0,3m, 0,4-0,6m, 0,7-0,9,1-1,2m, and 1,3-1,5m. The sedimentation rate in Mandeh estuary ranged from 60,85 up to 62,16 g.m-2.day-1, while in Nyalo estuary is approximately 48,86 g.m-2.day-1. The tidal current speed that is weak ranged from 0-0,05 m/s induces the sediment accumulation which mainly occurs during the neap tidal conditions. The thickness of sediment accumulation which is more than one meter identified around Mandeh River estuary and several areas near Carocok Tarusan Port where the sediment intake takes place and due to the weak current feature, it causes the increase of sedimentation in this region. Teluk mandeh merupakan kawasan teluk semi tertutup yang mempunyai 2 muara sungai besar yaitu sungai Mandeh dan sungai Nyalo. Masalah sedimentasi menjadi semakin parah karena pengembangan wilayah pesisir yang masif. Tujuan dari penelitian ini adalah untuk mengetahui ketebalan akumulasi sedimen di dalam Teluk Mandeh dan pola distribusinya. Pengukuran laju sedimentasi dilakukan pada dua fokus area yakni muara Sungai Mandeh dan Sungai Nyalo. Pengukuran parameter oseanografi (arus dan pasang surut) dilakukan selama 30 hari pengukuran. Ketebalan akumulasi sedimen diukur menggunakan alat Single Beam Echosounder Dual Frekuensi. Perhitungan volume sedimen dihitung dengan rumus frustum grid 10x10 meter. Simulasi flow model juga dilakukan untuk mengetahui pola distribusi sedimen. Sebaran ketebalan sedimen yang dibagi dalam 5 kategori spasial yakni 0-0,3m, 0,4-0,6m, 0,7-0,9,1-1,2m, dan 1,3-1,5m. Laju sedimentasi di muara Sungai Mandeh berkisar antara 60,85 sampai 62,16 g.m-2.hari-1 dan di muara Sungai Nyalo rata-rata 48,86 g.m-2.hari-1. Kecepatan arus pasang surut yang cukup lemah berkisar antara 0-0,05 m/s menyebabkan potensi akumulasi sedimen akan berlangsung terutama saat kondisi perbani. Sedimen dengan ketebalan lebih dari 1 meter teridentifikasi di sekitar Sungai Mandeh dan beberapa Kawasan Pelabuhan Carocok Tarusan dimana asupan sedimen mendominasi. Karena karakteristik arus yang lemah, sedimentasi meningkat diwilayah ini.]]>
