Abstract
The pollutants discharged from the islet are probably stayed in the lagoon for a long time, because the lagoon of Funafuti Atoll has closed environmental nature as the same degree as typical closed bays in Japan. In this study the numerical analyses were conducted in order to clearify the flow process of the pollutants under the typical wind condition at Funafuti Atoll, and to consider an appropriate water quality conservation measure in Funafuti Atoll. As a result of the calculations of reproducting water pollution mechanism in Funafuti Atoll, pollutants were found to stay nearshore on Fongafale Islet as long as the southeast wind wasn't blowing. Thus, pumping the water out of the nearshore area was considered as one of the water quality conservation measure in the lagoon. The caluculation results showed that about 14% of the pollutants were removed even by very small flow rate compared to the area of pollutants emission source. The efficiency of removing the pollutants was found to depend on the wind derection which changed seasonaly as well as the detailed distribution of pollutants. Local monitoring systems are indispensable to efficient operations of the measure.
