Modeling of Sediment Distribution and Changes of Morphology in Estuary Flow Kapuas River, West Kalimantan

Abstract

Pontianak Dwikora Port is a port that has been owned by Pontianak City since the Dutch colonial era and has been used as a trade center to export and import goods needed by West Kalimantan Province. Dwikora Port is located inside the Kapuas Kecil River and under the auspices of PT Pelabuhan Indonesia II (PELINDO II). Due to the location of the port in the river, the shipping channel is often disrupted due to silting (sedimentation) at the river mouth. So that the ships do not run aground, periodic dredging is carried out. This is to find out how much sediment is in the estuary. So, this study continues previous research by performing numerical modeling using Mike 21 software [1] to determine the sediment distribution flow patterns that affect silting that occurs in the Kapuas Kecil River Estuary. The data to be used are tidal data from field measurements, wind data from BMKG, wave generation data, river discharge, and TSS from previous research journals. The TSS used is derived from the river with the maximum taken from previous studies, namely 0.63 gr / L. The result is that the flow pattern of sediment distribution is strongly influenced by the confluence of flow patterns from rivers and sea. Sediment originating from the river slows down at the estuary as a result of the width of the river and is held back by waves from the sea, coupled with the tidal effect that occurs, the sediment oscillates and settles on the bottom of the mouth of the Kapuas Kecil River, causing changes in the basic morphology of the estuary.