Geography 12 PPT Worksheet: Rivers
A ________________ is the land area from which a river or stream
gets its ___________ supply. _____________ or ___________ are the
highland areas which ______________ one basin from another.
A ______________ river pattern is like the veins of a __________.
This pattern is found in ___________areas with a ___________
bedrock or surface.
A _____________ river pattern is found where there are differences in
the ______________ or in _____________________ regions. There
may be inclined layers of _____________ resistances that help form
this pattern.
A ___________________ pattern develops where there are long
______________ ridges in mountains or hills.
A ________________ river pattern develops around a volcano or
circular mountain or ____________ hill.
A _________________ river pattern develops over __________ which
has strong _______________ or joints in a rectangular pattern.
A _____________ river pattern develops where continental
___________ have __________ the land’s surface, rearranging the
flows of streams and rivers.
Rivers which flow year round are called ____________ rivers.
Rivers flowing only during a wet season are called _____________
rivers.
Rivers that __________ flow, every now and then, are called
________________________ rivers. Rivers in ____________ are
commonly ephemeral or intermittent.
A river or stream’s velocity is affected by _____________,
____________, ___________________ and __________________.
Geography 12 PPT Worksheet: Rivers
A stream’s _______________ refers to the ____________ of water
flowing ______________(m3/s) that it carries. A stream’s velocity is
__________________ to its discharge.
The profile, _______________ or degree of ___________ of a stream
affects its velocity with _______________ favouring _____________
velocities. Streams in _____________ have ____________ profiles
while streams in ______________ have more __________ profiles. A
stream typically flows ____________ near its mouth where it joins a
lake or ocean. Since rivers generally flow faster ______________
than upstream, _______________ is not the only factor affecting
stream velocity.
The ______________ the channel of a stream, the ______________ its
velocity which is _______________ by rough features slowing the
flow. ____________ in a river channel and __________ along the
bottom and sides of a channel _________ a river’s velocity. A mud
bottom has less _____________ than a rocky bottom which helps to
________________ a river.
A stream’s ________________ is the ratio of its cross-sectional area to
its wetted perimeter. A ___________ hydraulic radius generally
means ___________ friction which produces a ___________ flow and
therefore _____________ velocity. The hydraulic radius is a measure
of how ___________ a river flows.
For two rivers with the ___________ cross-sectional area, a
_______________ river has a _____________hydraulic radius which
produces a _____________ velocity. This is because the river water
has more contact with its channel which produces _______________,
slowing the river down.
Geography 12 PPT Worksheet: Rivers
For a river with an even channel, the water ______________ in the
______________, near the ___________. In deeper places the flow is
_____________ while in shallower places the flow is ___________
because there is ____________ surface contact and ____________ in
shallower places.
____________ of a stream’s bed and sides happens when the stream’s
velocity is higher. _________________ (very fine sand) erodes away
first. In low velocity streams, clay and silt are transported the easiest
________________ being carried in a river or stream is
______________ unless the velocity is very high. The ___________ a
river’s velocity, the _____________________ particles it can carry. As
a river slows down, it is likely to _______________ materials.
Water has four main erosion processes: _____________,
_____________, _______________ and ______________________.
The ____________ of a river’s bed and sides by suspended particles in
the moving water is called _____________.
The ________________ of rock and gravel fragments against each
other is called ___________________.
The _________________ of soluble minerals and transporting them to
an ocean is called __________________.
The reason _______________ are ______________ is that rivers
continually carry _________________ from their beds and sides to the
oceans.
The ___________ of moving water against the bottom and sides of a
river channel which slowly erodes it away is referred to as water’s
___________________. Water’s hydraulic action is more pronounced
in _____________ and ____________.
Geography 12 PPT Worksheet: Rivers
____________________ refers to the amount of __________-sized
particle that a river can erode and carry away.
The _________________________ of materials a stream or river
carries depends on its _______________ and the _______ of
sediments of the river. A river’s _____________ is the maximum
amount of _____________ materials that it can carry suspended in its
waters.
As the ______________ of a river increases (volume per time), the
capacity or sediment load increases _______________ by a factor of
two or three. For instance, if a stream’s discharge is ___________ in a
flood, its capacity may increase by _____________ times.
Streams carry particles by ______________, _____________,
______________ and ________________.
When streams ______________ along this is called ______________.
When ______________ are _____________ along the bottom of a
stream bed, this is called ______________.
________________ is the process by which water ______________
keeps particles afloat.
______________ is the process by which _______________
substances are carried by a river.
_____________ is the term used to describe river-deposited sediment.
Alluvium is usually deposited in _____________. _______________
are usually __________ because heavier particles settle out
__________, with the lightest (finest) particles settling out ________.
End of First Class on Rivers
Geography 12 PPT Worksheet: Rivers
As a river flows, especially with a more ____________ gradient
(slope), it _____________ (wanders sideways), creating broad curving
__________. River banks are ________ at the __________ edges, and
____________ occurs on the _________ curves creating features
called ____________. This happens because the _________ and
deepest water is found on the __________ banks while the _________
and ____________ water is found on the _________ banks of a
meander curve.
As erosion continues, meanders may ____________ causing incipient
____________ which later may become _______________ as
_____________ separate the meander from the main course of the
river.
Seasonal river floods _________ areas on either side of the river to
create a ____________. As fast-moving flood waters, _________ with
sediments, spill over onto surrounding ___________ flood plains, they
______________ and ___________ their sediments onto the _______
of the river and the flood plain. The raised edges of a river bank are
called ___________ and they are formed by flood waters __________
their sediments on the ___________ as they _________ in the
shallower bank region.
Moving away from a river with its levees, a person will find lower
regions which are referred to as ________________ areas.
A ________________ or stream maintains a __________, neither
___________ its bed nor ___________ further sediments. A
___________ stream carries an especially large load of ________ and
rock ____________ called its ___________. If a braided stream is
____________, it ___________ much of its sediment and _________
into many ______________________. Braided streams are common
in ______________ deserts (flatter) during _____________ and in
Geography 12 PPT Worksheet: Rivers
streams flowing from ______________. In both of these cases, a
sudden flood of water picks up a large amount of ____________ and
______________ these as they __________ down.
___________ are flat areas of __________ deposits found at river
____________. The cross-connecting channels in deltas are called
_______________. Deltas are ____________ as sediments are
deposited and are _________________ by the forces of ocean or lake
waves. Deltas may be ___________ or fan-shaped like the Nile delta
or elongated along the river channel like the Mississippi.
_______________ delta or ____________ or tooth-shaped like the
Tiber River delta.
In ______________ marshy areas where ___________ water rivers
meander and oceanic _________ periodically flow upriver, there is a
_____________ of waters and sediment deposit, forming an estuary
delta. The Cowichan river forms an ___________ delta where it flows
into Cowichan Bay. ______________ are regions where river waters
are ___________ and ___________before entering the ocean. They
are regions _________ in wildlife and in the Cowichan estuary,
plentiful in __________ for ___________ during both their ________
stage and last parts of their life cycle.
The complexity of the tributaries that feed into a river can be
measured with an _____________ system. A ________ order stream
has two tributaries of order 1 flowing into it. After two ________
order tributaries feed into a stream, it is called a _________ order
stream etc.
_______________ are deposits of sediment formed by fast-flowing
streams carrying large amounts of ____________ which abruptly flow
onto level plains, _____________ the flow and causing the sediments
to ________________ in the form of fans. Alluvial fans are common
Geography 12 PPT Worksheet: Rivers
in __________ or ___________ environments. Where several alluvial
fans grow together, structures called _____________ form.
In an enclosed basin with sloping ____________, the central flat plain
may intermittently fill up with water as a shallow _________ and then
dry through evaporation leaving __________ behind. The central flat
region is called a __________ and may have layers of
_______________, sometimes referred to as salt or alkali ________.
In deserts the dry remains of an ephemeral or intermittent stream is
called an ___________. When water erodes a desert, creating a
ravine or canyon, this is referred to as a _________. In more humid
climates, a wadi is referred to as a _________ or ____________.
_________ are flat-topped hills with steep sides or _______________.
Mesas develop in lands where a __________ layer of sedimentary
rock or igneous sill ____________ __________ sedimentary layers. A
___________ is a small mesa while a ___________ is just a pointed
remain of a butte. _____________ are regions of soft rock which
have been _____________ by intermittent water into _________,
gullies and sharp-edged ______________.
____________ rivers tend to be ___________, narrow with _______
moving waters due to the ______________ or gradients they have.
Youthful rivers have much erosion on their _________________ with
many ___________ and rocks that deflect their waters, causing them
to take __________ paths.
___________ rivers begin to ___________ because they have more
erosion at their __________ than their __________. They tend to
form narrow ___________ and __________ that they flow through.
Mature rivers have fewer _________ and ___________. Mature
Geography 12 PPT Worksheet: Rivers
rivers have a _________ profile (gradient) and a ____________ crosssection.
In old age rivers, most of their erosion takes place along their
__________. They form large ______________, large curving
____________ and __________ lakes. Old river have raised river
banks called _________ and away from these are lower-lying parts
called ____________. Old age rivers tend to be ________ and
____________.
When tectonic movements of the earth’s crust _________ a region
causing a steeper _____________ (profile), old age rivers may be
_______________, making the river once more into a “young” river.
With a ___________ gradient, the river now has more ___________
erosion, carrying away sediments and leaving just ________ and
___________ and again taking on a ___________ as it cuts downward
through its bedrock.
A river _________ tends to have major __________ erosion,
deepening its channel. Then a river tends to have more erosion at its
__________, causing its _____________ to __________. Later if the
land is _____________, the river may again have more ________
erosion followed once again with subsequent ________ erosion. This
pattern produces flat __________ that mark where former _________
___________ were.