Final answer:
Braided channels are common where rivers carry a substantial sediment load in erosive environments with steep gradients, variable water flow, and erodible bank materials. These rivers are often found near mountains, and flooding events contribute to their formation by altering sediment distribution.
Step-by-step explanation:
Conditions Favouring the Development of Braided Channels
Braided channels are prevalent in environments where the water carries a large load of sediment, and a high sediment supply is available due to erosion. Such conditions are favored by a combination of steep gradients, frequent fluctuations in water discharge, and an easily erodible bank material.
One typical environment where braided rivers may develop is at the base of mountain ranges where abrupt changes in gradient increase the river's capacity to transport sediment. As the river or stream flows away from its source, encountering a decrease in gradient and a widening of the channel, it slows down. The slowing of the current leads to enhanced sedimentation, creating the characteristic islands and multiple channels of a braided river. Flooding events, often resulting from the melting of ice or snow, can provide the sudden increase in water discharge necessary to redistribute and deposit sediments, leading to the formation and evolution of braided channels.