Different types of landscapes such as plains, wide valleys, gorges, dunes, rounded hills, and rugged ridges are formed largely by the forces of water, wind, and moving ice, which nibble, sharpen, and polish the surface of the Earth. Experts call this process ‘erosion’. These forces are much stronger than they appear. For instance, flowing water can move whole blocks of rock. The largest bits of rock thus eroded later become sand, which may be fine or coarse in texture and red, white, or grey in colour. Human beings also contribute to the constant changes taking place on the face of landscapes.
