Page - 370 - in Book of Full Papers - Symposium Hydro Engineering

During flood period, i.e. ①, ③, ⑤, ⑧, sediment balance within the river section showed positive (deposition). It is presumed that there was abundantly sediment supply from the upstream. In other hand, during the non-flood period, i.e. ② and ⑦, the balance of sediment within the river section shows negative because the volume of outflow is larger than the inflow. Meanwhile, the period ④ that spans both the flood and non-flood periods, is influenced both by the in-flow during the flood and the outflow in the non-flood season. As the result, the sediment balance showed negative in this case. Relationship between the sediment volume change in the river section by inSAR analysis and the sediment discharge observed at downstream end by the equipment is shown in Fig. 12. Although the data showed some dispersion, an approximate linear correlation was recognized. Fig. 12 Relationship between results by SAR image analysis and sediment observation 4. CONCLUSION In this study, even though it was difficult to precisely analyze and verify the results, because there was limited SAR image data taken in accordance with the flood event (immediately before/after), but the followings can be concluded from the above examination: 1) Combinating observation with trap pit can verify the accuracy of sediment observation with hydrophone as well as measure spatio-temporal sediment transport during flood event. By interference analysis of adjacent SAR images, it is possible to capture the change of micro topography in the riverbed. 2) This method can be fully utilized to measure and analyze geomorphologic changes in mountain streams where periodical survey is difficult. 3) In this study, clear correlation between sediment volume obtained by SAR analysis and observed one by hydrophone, turbidimeter, etc. was not be -15,000 -10,000 -5,000 0 5,000 10,000 Sediment volume by observation Vs(m3) Sediment transport volume 370