Why does the Yukon River have many channels in Yukon Flats?

The Yukon River features many channels in the Yukon Flats because it is a braided river flowing across a broad, flat valley. In this region, the river threads its way through numerous islands and sandbars.1

Generally, braided channels are characterized by the division of a river into multiple smaller, less efficient channels separated by midstream bars of sand or gravel. This pattern often occurs in rivers with weak banks, a high width-depth ratio, and mobile bed material. As the Yukon River moves through the Yukon Flats, this braided condition allows the water to distribute itself across the landscape, creating the complex network of channels observed in the area.21