広島湾における汚濁負荷と水質の季節変動特性

概要

論文の詳細を見る
The seasonal variations in pollutant loads and water qualities in Hiroshima bay, in order to get basic data for water quality modelling in that bay, were investigated. We have estimated inflow pollutant loads of freshwater, COD and nutrient into Hiroshima bay, also the budgets of the freshwater, salt, dissolved inorganic phosphorus (DIP) and dissolved inorganic nitrogen (DIN) by applying a simple box model in the northern coastal area (NH region) of Hiroshima bay were calculated.In the NH region of Hiroshima bay, influence of pollutant loads from land area was remarkable. We understood that phosphorus became limiting factor in the process of primary production because the standing stocks of nitrogen are enriched. The yearly averaged residence time of freshwater in the region is 16 days, and that of DIP and DIN is 24 days and 21 days, respectively. On the other hand, the yearly averaged internal sink or source of DIP and DIN, Δ DIP and Δ DIN in the NH region is estimated 25.5 ton · month-1 and 291.4 ton · month-1, respectively, and the ratio of Δ DIP to DIP loads (summation of inflow load and release flux from bottom sediments) is about 43 %, which is smaller than that of Δ DIN to DIN loads of 67 %.
社団法人　日本水環境学会の論文
2000-06-10