PREDICTION OF DREDGING EFFECTS ON FISH HABITAT IN SHIMATA RIVER BY USING DHABSIM

Abstract

For a low-cost habitat prediction of river fish community, we have proposed Eco-Environmental Diversity (EED) and DHABSIM solver on the river flow simulation platform iRIC. In this research, by using DHABSIM, we evaluated EED before and after renovation in the three Shimata river branches where dredging projects were scheduled. Although predicted EED and species richness showed good accordance with a survey result conducted after dredging before the flood season, the prediction accuracy for another survey conducted after the flood season was significantly reduced due to topographical changes and vegetation overgrowth. The prediction accuracy was improved by incorporating the riverbed fluctuation calculation using two-year probable rainfall intensity by using Nays2DH on iRIC.