[MIS24-17] Landform change analysis using images taken by interval shooting camera in the riverbed of the upper Azusa River in the Japan Alps
Keywords:landform change, riverbed, flooding, interval shooting camera, Azusa River, Japan Alps
The upper Azusa River flow down broad valley floor in the Japan Alps. This river course is the braided channel and gravel bed river. Several times of flooding occur in one year and major landform change is caused by bankful discharge which occurs once one to several years. From 2011 to 2015 we set interval shooting cameras which took pictures of the river course every 15 to 30 minutes. During the periods taken by these cameras landform changes of the riverbed occurred several times. The analysis of the landform change occurring under the water are carried out using these images. During rising stage of the water level deposition and erosion occurred in the existent channels. The new major channels were excavated tracing subchannels at about the bankful stage. After bankful stage much of water flew down in the new main channels. Minor flood caused slight lateral channel shift of existent channels and lateral erosion.