Streams erode their channel by abrasion by dissolving soluble material and by?

Streams erode their channels through abrasion, which involves the mechanical scraping of the channel bed and banks by sediment and rocks carried by the water. Additionally, they dissolve soluble materials through chemical weathering, particularly in limestone and other soluble rocks, where the slightly acidic nature of river water facilitates the dissolution process. This combined action of physical and chemical erosion shapes the stream channel over time, influencing its depth and width.