Impact Assessment of Dredging Plan in the Pasir Kambang Fishery Port, West Sumatera, Indonesia: Hydro-Oceanographic Perspectives

Dredging in estuarine fishing ports can alter hydrodynamic regimes and sediment processes, particularly in river–tidal interaction zones. This study aims to estimate the possible impact of dredging in the Pasir Kambang Fishery Port as a basis for future decision-making relating to port and coastal management. Hydro-oceanographic conditions were assessed using field measurements (ADCP, bathymetry, sediment sampling) and numerical hydrodynamic modeling. A dredging scenario of −1.5 m depth was simulated to evaluate changes in current characteristics, bathymetry, and sediment dynamics.

Currents in the study area are predominantly tide-driven, with flood phases generating stronger velocities than ebb conditions. Zonal current components range from −0.7 to 0.3 m/s, indicating dominant landward transport during high tide, which promotes sediment intrusion into the estuary. Bathymetry shows a shallow, irregular morphology, with maximum depths of 7.6 m near channel bends and average navigation depths of 3–4 m. The dredging simulation indicates negligible changes in current velocity (~0.001 m/s) and direction (~10°), suggesting minimal hydrodynamic response. However, slight reductions in bathymetric slope indicate localized morphological adjustments. Although dredging does not significantly modify current patterns, it may enhance erosion at the river–tidal interface and destabilize sediment balance in this highly dynamic estuary. The primary impact of dredging is therefore morphological and sedimentary rather than hydrodynamic.