中海本庄工区の水質特性

The Honjo area was artificially separated by dikes from brackish Lake Nakaumi for reclamation work in 1984. However, the work was frozen and the area still remains as a closed water area. The water of the area is interchange with the surface water of Lake Nakaumi through the one shallow channel, Seibushosuiro. Water quality of the Honjo area was surveyed during May to November in 1997 at 8 sites in the area, including 1 site in the Seibushosuiro and 1 site in Lake Nakaumi. A little vertical change in water quality was observed, and the strong halocline condition is not found in this area. Horizontal change of water quality was also a little. Water was well mixed vertically and horizontally. Only a station near the Honjo town was observed to be somewhat・high in nutrient and chlorophyll-a concentrations. Total nitrogen concentration in Honjo area was lower than that in the surface water of Lake Nakaumi, but in the other hand total phosphorus concentration was higher in the former than that in the latter.