In its upper course where the river channel is narrow, the river erodes downwards through the processes of hydraulic action, abrasion, attrition and solution., This downward erosion creates steep valley sides. Over time, rainwater and gravity transport soil and stones down the valley sides towards the river., As more debris from the valley sides is washed downhill, the valley eventually becomes V-shaped..

Bảng xếp hạng

Phong cách trực quan

Tùy chọn

Chuyển đổi mẫu

)
Bạn có muốn khôi phục tự động lưu: không?