A study used a computer model to simulate tides and currents in Daya Bay. The results matched observations well. Tides in the bay are mostly irregular and happen twice a day. The flow of water changes direction from south to north. Ebb tides move faster than flood tides. The fastest flow speed is 25.3 cm/s. Water flow is affected by the shape of the land, with faster speeds in narrow areas. Water movement doesn't change much with depth. In summer, the bay has weak self-cleaning abilities due to slow currents. In winter, stronger currents help clean the bay better.