Dynamics of radiocaesium within forests in Fukushima—results and analysis of a model inter-comparison

Forests cover approximately 70% of the area contaminated by Fukushima Daiichi Nuclear Power Plant accident in 2011. Following this severe contamination event, radiocaesium (137Cs) is anticipated to circulate within these forest ecosystems for several decades. Since accident, a number models have been constructed evaluate past and future dynamics 137Cs forests. To explore performance uncertainties we conducted model inter-comparison exercise using data. The main scenario addressed an evergreen needleleaf (cedar/cypress), which most common commercially important type Japan. We also tested with two management scenarios (decontamination removal soil surface litter regeneration) and, furthermore, deciduous broadleaf (konara oak) as preliminary modelling study forest. After appropriate calibration, reproduced observed data reliably ranges calculated trajectories were narrow early phase after fallout. Successful performances probably attributable availability comprehensive characterizing partitioning phase. However, envelope end points enlarged long-term simulations over 50 years It essential continue repetitive verification/validation processes decadal various types improve update forecasting capacity models.