An entropy based morphological variability assessment of a large braided river

The present paper utilizes entropy to investigate variability in the surface areas of sandbars distribution of the Brahmaputra River, India. The intensity entropy disorder index (IDI) was computed for the dry and the post-monsoon season for a selected reach of the river. The planform disorder index (PDI) was computed to represent the annual scale planform change due to seasonal flood. Finally, annual monsoon and peak flood stream power were evaluated and related to PDI. The results showed that the intensity disorder index followed a decreasing trend in dry and post-monsoon seasons; tending towards lower deviation from a uniform distribution. It was noted that except for extreme flood years the PDI trend correlated well with monsoonal stream power. Distinctive trends in stream power were also observed in the present study. (c) 2018 John Wiley & Sons, Ltd.