Ariake Sea, a typical enclosed bay on the west of the Kyushu Island, has been suffered with environmental damages. However it is still unclear which factor and process is dominant. In this study, field observation was conducted inside the artificial tidal flat to model the physical, chemical and ecological system in tidal flat for the preservation or recovery of the coastal environment in Ariake Sea. Three years pass after an artificial tidal flat was constructed; the habitable condition has been influenced with the ground lever, the ground bearing capacity, and the tide. In addition, the existence of tidal pool has been improved the water quality within an artificial pond “Yacho-no-ike”.
