The study looked at how waves and tidal currents shape the Yellow River Delta's coast. By simulating sediment movement, researchers found that waves play a big role in the abandoned estuary, causing erosion. In contrast, tidal currents dominate the current estuary, leading to sediment deposition and extending the estuary into the sea. Waves have a stronger impact on the abandoned estuary, while tidal currents are more influential in the current estuary.