Data in Selangor River Estuary_MG

This study investigates the sediment transport processes and ultimate deposition patterns in the Selangor River estuary, Malaysia- a representative tropical macrotidal estuary characterized by complex nearshore topography and weak Coriolis effects. By combining field measurements (2023-2024) with sediment analysis, this research reveals three key findings. First, approximately 73.5% of the annual sediment discharge (19.75×10⁴ tonnes)accumulates in estuarine tidal flats, with the northern tidal flats receiving twice the deposition of the southern tidal flats. Second, distinct seasonal transport regimes were evident: (i) during the dry season wave-driven sediment resuspension and tidal forces result in northwestward-southeastward transport, (ii) during the wet season stratified flows lead to significant sediment-freshwater decoupling, where river plumes disperse offshore while terrestrial sediments remain trapped near the estuary. Third, the unique sediment trapping mechanism, different from both large river systems and wave-dominated tropical SMRs, resulting from the interaction of strong tidal currents, seasonal river discharge, and offshore water intrusion form the Strait of Malacca. These findings provide a new conceptual framework for understanding sediment retention in tropical macrotidal estuaries, with implications for coastal management under changing climate change and intensifying anthropogenic pressures.