Fluvial Landforms
The cross profile shows the view of the valley from one
side to another and as the river moves from its source to
the mouth changes take place that result in distinctive
features.
Some of these features result from erosion, some from
deposition and some are a consequence of both processes.
They include;
Waterfalls
and rapids
Knick
points
Interlocking
spurs
potholes
Braided
channels
Fluvial
features
Meanders
(incised and
entrenched)
Ox-bow lakes
Deltas
Floodplains
and
river
terraces
Levees
V-shaped valleys
Hydraulic action causes intensive vertical erosion which
results in a steep sided valley.
The exact shape of the valley depends on
Geology – e.g. Limestone results in a steep sided valley
such as The Winnats Pass near Castleton.
Clays result in a more gently sloping valley side.
Climate – Higher precipitation levels are needed for the
increased discharge levels needed to give vertical erosion
and to move material from the valley sides.
Vegetation – vegetation will bind the soil together
leading to more stable valley sides – removal will lead to
increased soil erosion.
Interlocking Spurs
How do they form?
They form when the river winds its way round
hills or protruding ridges of land. In the upper
course of the river this may obstruct the view of
the river channel. Lower down the course, in the
middle stage, lateral erosion results in a wider
valley bottom and river bluffs may be found
(slopes at the edge of the floodplain)
So how does a v-shaped valley form?
1. ________ erosion (in the form of abrasion, hydraulic action
and solution) in the river channel results in the formation of a
s_____ s______ valley
2. Over time the sides of this valley are weakened by
w________ processes and continued v_______ e_______ at
the base of the valley
3. Gradually mass movement of materials occurs down the
valley sides, gradually creating the distinctive ___ shape.
4. This material is then gradually transported away by the river
when there is enough energy to do so.
As the river flows through the valley it is forced to swing from
side to side around more r______ rock outcrops (spurs). As
there is little energy for lateral erosion, the river continues to
cut down v_______flowing between spurs of higher land
creating _______ ________.
Task
Use the following link to find a photograph of an interlocking
spur – draw an annotated fieldsketch of the photo. You can
paste the photo onto this sheet.
http://www.geograph.org.uk/search.php?i=9036702