Numerical study of sediment and 137Cs discharge out of reservoirs during various scale rainfall events

IR

Bibliographic Information

Other Title
  • 様々なスケールの降雨イベント時にため池から流出する土砂・137Csの挙動特性に係る数値解析研究

Abstract

We performed simulations using the three-dimensional finite volume code FLESCOT to understand sediment and radiocesium transport in generic models of reservoirs with parameters similar to those in Fukushima Prefecture. The simulations model turbulent water flows, transport of sediments with different grain sizes, and radiocesium migration both in dissolved and particulate forms. To demonstrate the validity of the modeling approach for the Fukushima environment, we performed a test simulation of the Ogaki Dam reservoir over a typhoon. We simulated a set of generic model reservoirs systematically varying features such as flood intensity, reservoir volume and the radiocesium distribution coefficient. The results ascertain how these features affect the amount of sediment or $^{137}$Cs discharge downstream from the reservoirs, and the forms in which $^{137}$Cs is discharged. Silt carries the majority of the radiocesium in the larger flood events, while the clay-sorbed followed by dissolved forms are dominant in smaller events. The results can be used to derive indicative values of discharges from Fukushima reservoirs under arbitrary flood events.

Journal

Details 詳細情報について

Report a problem

Back to top