Multiple channels, bar migration, and high sediment load dynamics
Braided rivers form when sediment supply exceeds transport capacity, causing mid-channel bars to emerge and force flow around them. High stream power (steep gradient, high discharge) combined with coarse, abundant sediment — typical of proglacial and mountain systems — maintains the braided planform. Bars migrate downstream as flow erodes their upstream heads and deposits on their tails; channels shift laterally during floods, creating the interwoven pattern visible from above.