Abstract
Maps of the Fukuoka area from 1925, 1960, and 1994 are digitized and accumulated in the GIS. We evaluated changes in wetlands, such as paddy field, tidal flats, agricultural ponds and the coastline. The tidal flat that covered 193 hectares near Hakata Bay in 1925 was reduced to 163 hectares due to reclamation from 1925 to 1960. However, it stayed almost the same from 1960 to 1994. Both the population and the number of species of shore birds in two habitats in Hakata Bay did not changed significantly such as snipes and plovers from 1975 to 1985, suggesting that the habitats of the shore birds were not adversely affected after 1960. On the other hand, sea weed production along the tidal flats drastically decreased from 54 million sheets in 1965 to 46 million sheets in 1975, to zero in 1985. Further reseach is necessary in regards to the decline in sea weed production. Unlike tidal flats, the area of paddy fields, which did not significantly changed during 1925 to 1960, decreased by one fourth form 1960 to 1994. Paddy fields are being converted to residential areas as the population of Fukuoka is annually increasing at a rate of 1.72%.
