3rd Year Geography Revision Notes
Mass Movement
Study influences on mass movement:
• Gradient
• Water content
• Human activity
Mass movements classified by their speed, slow = soil creep, fast =
landslides, bogbursts and mudflows
Soil creep > moves at 1cm a year, rate of creep greatest at surface, only
noticed by its impact on the landscape, i.e. poles trees bent out of shape.
Landslides > rapid movement of earth and rock, occurs when slope becomes
unstable, can happen when base of a slope is undercut by quarrying road
building or erosion.
Bogbursts > Most common in upland areas with peat that have been
saturated. When this happens, peat moves downslope.
Mudflows > example of rapid mass movement, occur on both gentleand steep
slopes, They occur after torrential rainstorms + eruptions.
Revise case study of mudflow, p.34

3rd Year Geography Revision Notes
Rivers
Revise common river terms: source, course, tributary, confluence, mouth,
estuary, basin, watershed
Know the 3 stages of a river: youthful, mature and old age.
Youthful stage > associated with erosion
(hydraulic action, abrasion, attrition and solution )
Landforms of the youthful stage
V – shaped valley + Interlocking spurs:
• V – shaped valley formed by
vertical erosion and weathering
breaking up and weakening
valley sides, e.g. Lee, Moy.
• Interlocking spurs areas of high
ground that jut out from both
sides of a younger river valley
and lock into each other.

Waterfall:
Waterfalls develop in areas where a band of hard rock lies across a band of
soft rock. The river erodes the soft rock quicker than the hard rock, creating a
plunge pool, the falling water also cuts under the waterfall to form an
overhang, which eventually collapses, e.g. Powerscourt, Co. Wicklow
Revise processes of transportation: rolling, bouncing, suspension and
solution.
Mature stage landforms
Wider Valley + Meanders + Flood Plains
• Mature valley’s sides are less
steep and the floor is wider. The
river swings from side to side
removing interlocking spurs,
resulting in a widening of the
valley floor, e.g. Nore.
• Meanders are curves or loops that
form by erosion and deposition.
As the river flows around the bend
the outside bank flows quicker
and therefore has more power to
erode while the inside bendis
slower and deposits material,
widening the bend further, e.g.
Shannon.
• Flood plains are formed either
side of the river. In times of flood,
alluvium is deposited, gradually
this builds up to form an area of
flat land.

Old Stage landforms
Ox Bow lakes
Ox bow lakes are pronounced
meanders that were cut off.
During times of flood the river
flows straight through the neck
of land between the curves.
With vertical erosion, this
meander eventually gets cut
off.
Levees
Levees are raised banks of
alluvium formed during times of
flood. With continuous deposits
of alluvium, the banks either
side of the river gradually
become bigger. E.g. Po
Deltas
A delta is a triangular –
shaped area of land formed at
the mouth of a river. With loss
of speed as it enters the sea,
the river deposits sediment.
This builds up to form a delta
with small rivers running
through it called distributaries
The 2 case studies on flooding in the Mississippi and dam building in Ireland
are both very relevant in this chapter, I would also recommend having a look
over the Shannon study as it ties in with many other topics