Page - 364 - in Book of Full Papers - Symposium Hydro Engineering

The observed results of the hydrophone and sediment trap pit showed that the detectable grain diameter lower limit by hydrophone is about 2 mm, and the volume of sediment measured by the hydrophone is about 2% to 50% of the actual flowing down sediment volume that deposited in trap pit [1], and the ratio depends on the flood conditions such as the season, water depth and so on (Table 1, Fig. 5). Fig. 2 Observation equipment installed in Omukawa River 50th groundsel Fig. 3 Observation data from hydrophone, turbidimeter and water level gauge Kamanashigawa River Omukawa River Installation of observation equipment Sedimentation pit Suspended load meter Water gauge / turbidimeter Hydrophone Bed load sampler Portable observation equipment Current meter Water gauge / turbidimeter Suspended load sampling pipe 50th Groundsel, Omukawa River 2014/4/1 2014/12/1 2015/1/31 2017/4/1 1.0E-07 1.0E-06 1.0E-05 1.0E-04 1.0E-03 1.0E-020 50 100 150 200 250 2014/7 2014/10 2015/1 2015/4 2015/7 2015/10 2016/1 2016/4 2016/7 2016/10 2017/1 2017/4 2017/7 2017/10 1.0E-08 1.0E-06 1.0E-04 1.0E-02 1.0E+00 1.0E+020 50 100 150 200 250 2014/7 2014/10 2015/1 2015/4 2015/7 2015/10 2016/1 2016/4 2016/7 2016/10 2017/1 2017/4 2017/7 2017/10 0.0 1.0 2.0 3.0 4.0 5.00 50 100 150 200 250 2014/7 2014/10 2015/1 2015/4 2015/7 2015/10 2016/1 2016/4 2016/7 2016/10 2017/1 2017/4 2017/7 2017/10 1 2 3 4 5 6 7 8 ※ ①～⑧shows the period of SAR image data at Table 2 Rain fall:Hakushu observation station 364