Estimation of Cs discharge from river catchments using a tank model

Sakuma, Kazuyuki; Zheleznyak, M.*; Namba, Kenji*

no journal, , 

To understand how much radiocesium discharge to a reservoir and the ocean through rivers from catchments is important for residents and municipal officials from immediately after Fukushima accident to the present. It is not easy to estimate Cs discharge from catchments based on observations because there are many processes such as continuous monitoring of water level and turbidity and Cs concentrations in river water to estimate Cs discharge fluxes. Therefore we developed a user-friendly model that is composed of tank model, which can predict water discharge easily, relationships between water discharge and suspended solids load, and two-component exponential models for Cs concentration in river water. Using developed model we estimated Cs discharge to the ocean from Abukuma River catchment and several rivers in coastal region from immediately after Fukushima accident to 2017.