CONCEPTUAL MODEL FOR BOTTOM LAYER VOLUME BY TAKING INTO ACCOUNT RIVER FLOOD

Abstract

 We developed a conceptual model for bottom layer volume in order to evaluate bottom layer volume exchange due to river flood with a large peak discharge. Three-dimensional environmental fluid dynamic model was applied to calibrate the conceptual model with a good agreement. It was found from 3D hydrodynamic model analysis that bottom layer volume is exchanged greater when the maximum displacement of density interface is larger than the critical amplitude. It was revealed that occurrence of total amount of rainfall more than 50 mm was three times in the periods from 2012 to 2016 as much as from 1990 to 2011, which caused more exchange of bottom layer water.