Reviewing braiding indices of the river channel in an attempt to establish alternatives

Complex channel planform especially the dynamics of the multi-thread river is empirically examined using the three major dimensions – bar growth, channel length and channel count. To this end, many indices have been proposed to deal with the complex channel response in the context of sediment-energy synergistic scenarios. The existing methods are primarily concerned with the linear or 1D nature of the channel and bar. The present study introduced the areal or 2-D nature of the channel and bar to capture a more realistic picture because, with same length, area of the bar may differ greatly. Therefore, we proposed four indices on channel braiding taking into consideration the area of the channel and bar. We tested our indices to the 28 reaches of the Damodar River, India that showed a significant correlation (∼80%) with the existing standard method. The major highlights of the methods are outlined as follows. • Four novel indices were proposed considering the linear and areal dimensions of the channel and bar. • Proposed indices focus on the unit-free measures with known limits enabling pragmatic comparison with self and other channels. • New methods were tested using field data implying a significant correlation with the existing methods.