Observation of total load in upstream of the Abe river
Reiji KONDO, Toshihiro HASHINOKI, Yuji YASUDA and Satoshi TUCHIYA
Abstract
To resolve the problems resulting from sediment discharge, it is required to treat
the entire area of sediment as the gsediment transport system". To enable
this, the actual state of sediment discharge must be grasped. In the case of mountainous
rivers, it is desirable to trap sediment discharge at all depths, because bed
load and suspended load and washload flow down being mixed. We developed the Total
Load Trapping Equipment that can trap all sediment discharge passing through the
overflow section at the unit width. We placed it at the Oshima check dam in Abe
river and measured the sediment discharge. Based on the observations, the sediment
discharge was quantified by sediment movement type and the following knowledge
was gained; (1) In the case of floods of normal year scale, suspended load plus
washload account for a far greater ratio than that of bed load in the total sediment
discharge flowing down a mountainous river; (2) The suspended load plus washload
obtained at this river was greater by one order than those obtained at other rivers;
(3) The bed load estimated by the Ashida, Takahashi,and Mizuyama's formula was
greater by 3]5 orders than the measured amount in many cases, but the difference
was within 1]2 orders in some cases obtained at peak flow rate. The bed load estimated
by the Meyer Peter, Muller's formula was generally smaller than the measured amount,
but the difference remained within 1]2 orders.