2013.4 - 2014.3 Yearbook of NILIM

Research Summary


River Department
Reference Number Y130202
Title Study on environmental conservation in the riverine estuaries damaged at large-scale.
Start-End Date 2013.4-2014.3
Division River Division, River Department
Author Head, Atsushi HATTORI
Senior Researcher, Keigo NAKAMURA
Researcher, Hiroyuki SUZUKI
Guest Research Engineer, Yoshiyuki MAEDA
Summary In this study, we collected the data of geomorphology and biology on five major rivers along the Pacific in Tohoku district, and analyzed the influence of the Great East Japan Earthquake. Comparing the geomorphology in riverine estuaries before and after the earthquake, we found the loss of river-mouth sandbar and the vegetation at riverine estuaries. Changes of biota and littoral habitat by extension of the salt water and the formation of the salt stratification by the disappearance of the river-mouth sandbar and land subsidence were confirmed. Habitat of littoral ecotone and the river mouth sandbar were in recovery state, therefore it was assumed that these influence could gradually recover with time.