[A-CG42] 陸域〜沿岸域における水・土砂動態

[ACG42-05] 七尾湾表層塩分を用いた集水域からの淡水流入量の推定

*小林 志保¹、中田 聡史²、仙北屋 圭³、奥野 充一³ (1.京都大学、2.国立環境研究所、3.石川県水産総合センター　)

キーワード：淡水流入量、集水域、表層塩分、沿岸海域モデル、流出係数

Extremely heavy rainfall impacts on marine environment; it causes the significant decrease of surface salinity and intensifies density stratification in coastal seas, and might result in depletion of dissolved oxygen in the lower layer. The study area, Nanao Bay is a semi-enclosed bay in Noto Peninsula faced on Japan Sea. There is no public data of river discharge flowing into the bay, which is important to investigate the impacts of heavy rainfall on the marine environment. On the other hand, salinity in the bay has been monthly measured by Ishikawa Prefecture Fisheries Research Center and daily rainfall is publicized by Japan Meteorological Agency. This study employed a numerical model, FVCOM (Chen et al., 2003) for estimating the decrease of salinity in the surface layer of the bay associated with freshwater discharge which was estimated using the catchment area, rainfall data and runoff coefficients. The Green’s functions method was then applied for inverse estimation of the runoff coefficients using the simulated and the observed salinity in the bay.