GEOG 3000 - Practice Questions
Explain how the mechanisms of central bar deposition differ from the transverse bar conversion.
● Central:
○ Forms in the middle of the channel
○ Bedload sheet migrates downstream
○ Bedload sheet stalls and deposits coarser fractions
○ Bar grows horizontally and vertically
● Transverse:
○ Extends across the channel
○ Transverse bar with slip face downstream
○ Bedload sheet stalls on bar
○ Flow deflected around emerging bar
Consider the many examples of environmental degradation caused by human activities within a
watershed discussed in the course. Describe an example and its direct impacts on the fluvial system.
● Humans construct dams in river systems for hydroelectric purposes or to control water flow
● Becomes difficult for fish and other aquatic species to move downstream through a dam
● Sediment also gets trapped at the top of the damn
○ Lots of sediment in water blocks sunlight to aquatic plants - difficult to produce
necessary oxygen (hypoxic conditions)
○ Lack of sediment downstream of the dam influences interactions between flow,
deposition, turbulence, and biotic interactions
○ Sediment helps to create various bedforms which then cause turbulence and areas
where aquatic species tend to inhabit
○ Sediment - particularly along the banks - helps to prevent bank erosion
● Dam interferes with natural or average flow regimes and hence can cause a number of
problems downstream
In the course we discussed several of the flow resistance coefficients, select one of them, explain it,
and describe its advantages and limitations.
● Chezy coefficient (C)
○ Based on gravitational and frictional forces
○ Value decreases with increasing roughness
○ As C decreases, velocity decreases
○ Varies with hydraulic radius, slope, and physical boundary roughness
● Disadvantages
○ Tends to be limited by the variation in flow resistance with stage
■ Resistance is greatest at low flows
■ Resistance is lowest at bankfull
○ Not backed by significant experimental results
● Advantages
○ Great for smooth boundaries
, ○ Useful to determine flow in an open channel or pipe
Throughout the course we discussed the sediment regime and how it may become disrupted or
altered. Using an example from the course, explain the cause and impacts of a major change in the
sediment regime.
● Land use change
● Removing vegetation from a landscape destabilizes sediment
● More sediment is wash into rivers and out into the ocean
● Less stable banks also mean greater erosion of river banks and overall less stability
surrounding these banks
● More bends in a bank can alter water chemistry
● Overtime there will be less sediment available on land and to flow into river systems as a lot of
the sediment will be deposited in oceans
Given the following scenario, which basic equation category does it belong to, according to Dingman
(1984) as explained in Robert 2003? Several experiments were designed and run on a scaled flume in
the laboratory to determine the bed shear stress.
● a) Conservation
● b) Empirical
● c) Diffusion
● d) Fluxes
● e) Definition of forces
Given the following scenario, which basic equation category does it belong to, according to Dingman
(1984) as explained in Robert 2003? A sediment budget was completed for a fluvial system by
evaluating the inputs, outputs and changes in storage variables.
● a) Empirical
● b) Fluxes
● c) Definition of forces
● d) Conservation
● e) Diffusion
Given the following scenario, which basic equation category does it belong to, according to Dingman
(1984) as explained in Robert 2003? A study was completed that evaluated how bedforms migrated
along a sandbed channel, and this work had some observations, but also relied on assumptions about
momentum.
● a) Conservation
● b) Fluxes
● c) Diffusion
● d) Definition of forces
● e) Empirical
Explain how the mechanisms of central bar deposition differ from the transverse bar conversion.
● Central:
○ Forms in the middle of the channel
○ Bedload sheet migrates downstream
○ Bedload sheet stalls and deposits coarser fractions
○ Bar grows horizontally and vertically
● Transverse:
○ Extends across the channel
○ Transverse bar with slip face downstream
○ Bedload sheet stalls on bar
○ Flow deflected around emerging bar
Consider the many examples of environmental degradation caused by human activities within a
watershed discussed in the course. Describe an example and its direct impacts on the fluvial system.
● Humans construct dams in river systems for hydroelectric purposes or to control water flow
● Becomes difficult for fish and other aquatic species to move downstream through a dam
● Sediment also gets trapped at the top of the damn
○ Lots of sediment in water blocks sunlight to aquatic plants - difficult to produce
necessary oxygen (hypoxic conditions)
○ Lack of sediment downstream of the dam influences interactions between flow,
deposition, turbulence, and biotic interactions
○ Sediment helps to create various bedforms which then cause turbulence and areas
where aquatic species tend to inhabit
○ Sediment - particularly along the banks - helps to prevent bank erosion
● Dam interferes with natural or average flow regimes and hence can cause a number of
problems downstream
In the course we discussed several of the flow resistance coefficients, select one of them, explain it,
and describe its advantages and limitations.
● Chezy coefficient (C)
○ Based on gravitational and frictional forces
○ Value decreases with increasing roughness
○ As C decreases, velocity decreases
○ Varies with hydraulic radius, slope, and physical boundary roughness
● Disadvantages
○ Tends to be limited by the variation in flow resistance with stage
■ Resistance is greatest at low flows
■ Resistance is lowest at bankfull
○ Not backed by significant experimental results
● Advantages
○ Great for smooth boundaries
, ○ Useful to determine flow in an open channel or pipe
Throughout the course we discussed the sediment regime and how it may become disrupted or
altered. Using an example from the course, explain the cause and impacts of a major change in the
sediment regime.
● Land use change
● Removing vegetation from a landscape destabilizes sediment
● More sediment is wash into rivers and out into the ocean
● Less stable banks also mean greater erosion of river banks and overall less stability
surrounding these banks
● More bends in a bank can alter water chemistry
● Overtime there will be less sediment available on land and to flow into river systems as a lot of
the sediment will be deposited in oceans
Given the following scenario, which basic equation category does it belong to, according to Dingman
(1984) as explained in Robert 2003? Several experiments were designed and run on a scaled flume in
the laboratory to determine the bed shear stress.
● a) Conservation
● b) Empirical
● c) Diffusion
● d) Fluxes
● e) Definition of forces
Given the following scenario, which basic equation category does it belong to, according to Dingman
(1984) as explained in Robert 2003? A sediment budget was completed for a fluvial system by
evaluating the inputs, outputs and changes in storage variables.
● a) Empirical
● b) Fluxes
● c) Definition of forces
● d) Conservation
● e) Diffusion
Given the following scenario, which basic equation category does it belong to, according to Dingman
(1984) as explained in Robert 2003? A study was completed that evaluated how bedforms migrated
along a sandbed channel, and this work had some observations, but also relied on assumptions about
momentum.
● a) Conservation
● b) Fluxes
● c) Diffusion
● d) Definition of forces
● e) Empirical
