Page - 369 - in Book of Full Papers - Symposium Hydro Engineering

appeared and if there is no flood in a long term, a tendency of river bed decrease (erosion) is recognized due to the sediment gradually flowing out. 3. RESULTS 3.1. RESULT COMPARISON AND ITS CONSIDERATION A comparison of transport sediment volume (bedload and suspended load) observed by equipment (hydrophone, turbidimeter, water level gauge etc.) installed at the downstream end in Omukawa River and that calculated from SAR image interference analysis in the same period is shown in Table 4 and Fig. 11. Table 4 Comparison between results by SAR image analysis and observation No Analysis period Period (Day) Sediment change in volume by inSAR analysis Vss (m 3) Sediment discharge observed by hydrophone VsH(m 3) Event occurred in the period from to ① 2014/09/19 2014/11/28 70 5846.39 -1469.05 Typhoon18 Typhoon19 ② 2014/11/28 2015/04/03 126 -3217.05 -2234.88 ③ 2015/04/03 2015/06/26 84 1104.04 -514.11 ④ 2015/06/26 2016/03/18 266 -12737.73 -10970.63 Typhoon11 Typhoon18 ⑤ 2016/03/18 2016/06/24 98 5851.40 -1312.48 ⑥ 2016/06/24 2016/11/25 154 959.43 -12317.24 Typhoon9 Typhoon16 ⑦ 2016/11/25 2017/03/03 98 -388.99 -1458.5 ⑧ 2017/03/03 2017/06/09 98 5757.61 -1483.2 ※ Sediment change in volume revised by void ratio of river bed material (0.40) Fig. 11 Comparison between results by inSAR image analysis and observation -15,000 -10,000 -5,000 0 5,000 10,000 15,000 ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ Analysis period No. Sediment volume change by inSAR analysis Vs Sediment volume by observation Vs Deposition Erosion 369