Flow Patterns and Morphological Changes in a Sandy Meander Bend during a FloodSpatially and Temporally Intensive ADCP Measurement Approach

Abstract

<p>The fluvio-geomorphological processes in meander bends are spatially uneven in</p><p>distribution. Typically, higher velocities and erosion take place near the outer bank beyond the</p><p>bend apex, while the inner bend point bar grows laterally towards the outer bank, increasing the bend</p><p>amplitude. These dynamics maintain the meander evolution. Even though this development is found</p><p>in meandering rivers independent of soil or environmental characteristics, each river still seems to</p><p>behave unpredictably. The special mechanisms that determine the rate and occasion of morphological</p><p>changes remain unclear. The aim of this study is to offer new insights regarding flow-induced</p><p>morphological changes in meander using a novel study approach. We focused on short-term and</p><p>small-spatial-scale changes by conducting a spatially and temporally (daily) intensive survey during</p><p>a flood (a period of nine days) with an ADCP attached to a remotely controlled mini-boat. Based on</p><p>our analysis, the flood duration and the rate of discharge increase and decrease seems to play key</p><p>roles in determining channel changes by controlling the flow velocities and depth and the backwater</p><p>effect may have notable influence on the morphological processes. We discuss themes such as the</p><p>interaction of inner and outer bend processes and the longer-term development of meander bends.</p>