Abstract
This study examined effects of land load on the water environment of the Ariake Sea. The land and sea areas were examined by classifying them to western, inner, and eastern parts. Impact of the inflow water on each water quality has been grasped by the correlation analysis. In the period from 1981 to 2010, NO3-N, plankton deposition, DO and DIN decreased, while PO4-P, NO2-N, COD and transparency increased in the Ariake Sea. The increasing effect of the inflow water from the land on the western part sea is estimated with respect to the nutrient after 1997. Water quality in the eastern part is considered to be characterized by inflow loads characteristics of the basin. Water quality of the inner part is considered to be strongly influenced by the inflow loads. Water quality of the western part is considered to be dependent on the loads from the Isahaya Bay regulating reservoir.
