1 Name the waterfalls 2 3 4 Name

1 Name the waterfalls 2 3 4 Name the waterfalls 5

1 Angel Falls, Venezuela Name the waterfalls Iguazu Falls Argentina, Paraguay and Uruguay 2 3 4 Victoria Falls, Zimbabwe and Zambia Niagara Falls, USA & Canada Tugela Falls, South Africa Name the waterfalls 5

Upper valley characteristics “V”shape valley, mostly vertical erosion Interlocking spurs Narrow, shallow channel, low velocity and discharge Large rocks that come from upstream and from valley sides

Interlocking spurs, Robinson, Lake District An upper course valley often has interlocking spurs, and steep valley sides

River load in upper course Why are they rounded? 6

River load in upper course Why are they rounded? Boulders are large and semirounded, due to attrition within the load and abrasion with the stream bed and banks 7

The river erodes the weaker rock more quickly than the more resistant rock. The more resistant rock is undercut creating an overhang

The river erodes the weaker rock more quickly than the more resistant rock. The more resistant rock is undercut creating an overhang Overtime the resistant rock is undercut more and more making it unstable because it isn’t supported any longer by the weaker rock.

The river erodes the weaker rock more quickly than the more resistant rock. The more resistant rock is undercut creating an overhang Increased river velocity means more erosion takes place and a plunge pool develops. Overtime the resistant rock is undercut more and more making it unstable because it isn’t supported any longer by the weaker rock.

Eventually the more resistant rock collapses and the process starts again.

These large fragments of hard rock are used by the river to erode. As they get Eventually the more resistant transported downstream they become smaller and more rounded due to rock collapses and the attrition, corrasion and corrosion. process starts again.

Task Match the statements to the pictures

Overhang Plunge pool Upstream Waterfall retreats Undercutting of soft rock Task Label the photo

WATERFALL RETREATS. . UPSTREAM. . OVERHANG UNDERCUTTING OF SOFT ROCK PLUNGE POOL

How are waterfalls formed? Copy out the paragraph below and insert the missing words from the word bank. Waterfalls occur when ______ flow over different types of ____. The ____ rock wears away faster than the ____ rock. In time a step develops over which the river _______ as a waterfall. _____also cuts away rock behind the _____. This causes the falls to move back and leave a _____ as it goes. HARD SOFT GORGE RIVERS WATERFALL WATER PLUNGES ROCK

How are waterfalls formed? Copy out the paragraph below and insert the missing words from the word bank. Waterfalls occur when RIVERS flow over different types of ROCK. The SOFT rock wears away faster than the HARD rock. In time a step develops over which the river PLUNGES as a waterfall. WATER also cuts away rock behind the WATERFALL. This causes the falls to move back and leave a GORGE as it goes.