What does the ability of a stream to erode and transport materials depend largely on?

The ability of a stream to erode and transport materials largely depends on its velocity and discharge. Higher flow velocity increases the stream's energy, allowing it to erode the riverbed and banks more effectively while transporting larger sediment particles. Additionally, the gradient of the streambed and the size, shape, and composition of the sediment also play significant roles in determining the stream's erosive and transport capacity.