Cohesive Sediment Transport Modeling on Inner Ambon Bay

Abstract

<jats:p>The presence of cohesive sediment in the water column can reduce light penetration and affect photosynthesis process, and it can be disrupted the primary productivity of aquatic, and sedimentation of coastal waters. The objective of this research was to determine the cohesive sediment distribution pattern and the relationship with sedimentation. MIKE 3 FM modeling was used to understand the process of sediment transport and sedimentation on Inner Ambon Bay. Sediment transport modeling method was divided into two stages: the hydrodynamic modeling (baroclinic) and sediment transport (mud transport) modeling. The model results indicate current patterns in the Inner Ambon Bay is influenced by the tidal factor. Suspended sediment dispersed vertically from the surface to a depth of 30 m with concentration of about 3.5-15 Kg/m3. The maximum consentration of the suspended sediment occurs at head of the bay (around Waiheru, Passo, and Lateri). Model simulations for 30 days showed the rate of erosion is about 1.04-6.15 Kg/m2/s, while in Inner Ambon Bay the erosion about 9.07x10-8Kg/m2/s only occurred in T1 station. Sedimentation associated with the cohesive sediment accumulation and it was shown by bed level. In addition, the simulation showed bed level in sill ranged at 0.01-0.19 cm and 0.47 mm/day on average, while in the Inner Ambon Bay it ranged from 1.75-10.01 cm, and the sedimentation rate was approximately 39.9 mm/day.</jats:p>

Growth and reproductive biology of white-spotted rabbitfish (Siganus canaliculatus) on different seagrass habitats in Inner Ambon Bay, Indonesia

“…It is due to the location of the monospecific seagrass habitat, which is attached to the river flow. The high sedimentation in the Inner Ambon Bay due to land activities has threatened the existence of seagrass habitats (Irawan and Nganro 2016), with sediment transport rates reaching the range of 1.75-10.01 cm or about 39.9 mm/day (Noya et al 2016). According to Quiros et al (2017), Agricultural land activities and other anthropogenic activities on land harm seagrass conditions that affect the ecological integrity of seagrasses near watersheds.…”

“…Therefore, it may threaten the presence of S. canaliculatus directly in Inner Ambon Bay. In addition, the high rate of sedimentation in the Inner Ambon Bay (Irawan and Nganro 2016;Noya et al 2016) threatens the existence of seagrass beds as a habitat for S. canaliculatus, thus indirectly potentially reducing. Therefore, it is necessary to develop in situ conservation areas.…”

“…In the Inner Ambon Bay, S. canaliculatus has a strong relationship with various types of seagrass meadows Latuconsina et al 2020 a ). It can reach maturity at six months of age, with higher fishing mortality and exploitation rates (Manik 1998;Latuconsina et al 2020 b ), high sedimentation pressure on seagrass habitats (Irawan and Nganro 2016;Noya et al 2016). Besides, it will also affect seagrass vegetation, which can impact the growth and reproductive biology of S. canaliculatus.…”

Prediksi Laju Sedimentasi di Perairan Teluk Benoa Menggunakan Pemodelan Numerik

“…Perairan Teluk Benoa dilaporkan telah mengalami pendangkalan (tribunnews, 2016), hal ini terlihat juga dengan aktifitas pengerukan jalur pelayaran yang dilakukan oleh PT Pelindo. Pendangkalan estuari dapat terjadi dimana-mana akibat dari proses transport material, baik terbawa oleh sungai maupun run off secara langsung dari daerah daratan (Qiao et al, 2009;Kessel et al, 2011;Chizom Dike and Agumwamba, 2013;Solihudin et al, 2014;Weilbeer, 2014;Roswaty et al, 2014;Ge et al, 2015;Guerreiro et al, 2015;Noya et al, 2017;Kim et al, 2017). Laju sedimentasi yang tidak terkontrol akan berakibat pada proses pendangkalan yang semakin cepat sehingga dapat mengakibatkan rusaknya ekosistem dan berdampak pada sulitnya nelayan untuk mendapatkan hasil tangkapan.…”