Why is it a fallacy to retain sediment in a retention or storage basin, without protecting the downstream channel against degradation?

According to Lane, the width-to-depth ratio of a self-formed river is a function of two variables. What are these variables?

In what direction will a bed disturbance propagate? Upstream or downstream? Explain.

What is wash load? What channel property determines whether a certain particle size will constitute wash load, or not?

What is the primary limitation of the Colby 1964 method for the transport of sands?

What is the range of variation of the exponent m in the unit-width sediment discharge vs. mean velocity, for a given flow depth? What value of this exponent renders the sediment transport relation dimensionless?

To what process did Prof. Hans Einstein attribute the apparent drop in sediment transport rate at low discharges, i.e., in lower regime?

Of what variable is the Brune [sediment] trap efficiency of a reservoir primarily a function of? All other variables [factors] being equal, which reservoir system will fill up faster:

• One (1) reservoir having X volume, or

• Two(2) reservoirs having X/2 volume each?

What is the difference between general scour and local scour? What is the difference between clear-water scour and live-bed scour?

How does unsteady sediment transport rate affect pier failure during a flood event?

Bonus question (can be used to replace any two of the above questions): Is Prof. Ponce's 1988 article on sediment rating curves:

• fundamentally correct,

• correct given the proper conditions, or

• hopelessly flawed.