This short test is designed to measure the users’ level
of understanding of the basic process that control landform development
after using WILSIM. When taken in conjunction with the PRE-TEST it will allow
WILSIM designers to determine how effective the model is as an educational
1. What is the definition of “Runoff”?
A. Water flowing across the land surface (overland flow) during or
after a rainfall event.
B. Water infiltrating into the soils or porous rock at the land surface
during a rainfall event.
C. “Rain drop splash” that erodes the land surface.
2. What is necessary in order for Runoff to occur across the land surface?
A. Rainfall events must be slow and gentle such that all precipitation
infiltrates or soaks into the land
surface or soils.
B. The duration of a rainfall event must be long enough, or produce
a sufficient volume of precipitation
to saturate the soils or rock at the land surface such that the excess
water will flow overland
(across the land surface).
C. Runoff is only possible if the land surface is completely impermeable
to rainfall water (it won’t let any water infiltrate downward into the
soil or rock).
D. Runoff is only possible after torrential downpours of rain.
3. What is the definition of a drainage network or drainage system?
A. A single river channel that flows across the land surface.
B. A series of short unconnected stream segments or gullies that can
be seen along a sloping land surface.
C. An integrated branching arrangement of smaller streams joining
together to feed larger streams that then feed one or more main river channels.
D. A random arrangement of streams that may or may not connect and
that flow in seemingly
4. Concerning the time frame over which drainages develop, why are numerical models such
as WILSIM so valuable?
A. They can compress time so that during a brief model run you can
observe the evolution of a drainage
system that would take place over long periods of geologic time.
B. They allow you to explore and appreciate the effects of different
factors on landform.
C. They allow you to study the evolution of a drainage system in front
the need to do field work.
D. Both A and B.
5. When flowing water erodes the land surface to create a drainage network, do these drainages always develop at the same rate everywhere in nature or in a computer model?
6. What do you think the best definition for “erodibility” would be?
A. The degree to which a surficial material is resistant to erosion
by flowing water. Some rock types and soils are easily eroded and some are very
resistant to erosion.
B. The rate at which streams transport eroded sediments down slope
or down stream.
C. The degree of steepness for slopes and stream channels in a drainage
D. The change in slope from one portion of a drainage to another.
7. The term “Tectonics” refers to which of the following?
A. The form of an entire drainage basin.
B. The slope of the land surface.
C. The process by which drainages form.
D. Deformation of the Earth’s crust and surface which serves to create
changes in land surface slope (such as the formation of mountains
8. Which of the following do you think would be the primary variable
that controls the rate of drainage network development?
A. Climate; including the amount of rainfall and the vegetation cover.
C. The durability of the surface rock or soil and how easily it can
D. The steepness of the slope over which the streams flow and erode.
E. All of the above are primary or important variables.
9. WILSIM can also simulate the affects of climate change upon drainage
form or morphology over time (i.e., initially dry then evolving into a wetter
climate or vice versa). How do you think climate change would affect drainage
A. It would not affect the morphology, only the rate at which the
B. Because the rate at which material is transported downslope to
the developing stream changes as climate
changes, the morphology of the drainage as well as the rate of development
10. Define Cross Section in a geographic sense.
A. The statistical distribution (or histogram) of the elevation measurements
for many or all points in a
land surface grid.
B. A profile of the elevation along a specific line across the land
C. The general surface slope or change in elevation from one point
on a land surface grid to another .
11. What is a Hypsometric Curve?
A. A nondimensional curve that essentially describes the relative
proportion of a watershed that lies at or above a given height relative
to its total elevation range .
B. The longitudinal profile of elevation along a major stream from
its source (highest elevation) to its mouth (lowest elevation).
C. A measurement of the total volume of sediment eroded from one
part of a basin and deposited in another part.
D. A measure of the sinuosity of a stream channel (measures how curvy
the stream channel is).
12. Where in the landscape do you think the deposition (accumulation
of eroded and transported sediments) would most unlikely to occur?
A. In places where the slope is very steep.
B. In places where the slope is very gentle.
C. In places where there is a change in slope from steep to gentle.
D. In places where the stream enters an open waterbody such as lake
13. If all variables for two model runs are identical, why do dendritic
drainages develop in different locations and with slightly different morphologies
across the landscape grid?
A. Because anisotropy of rock type (variations in erodibility) is
an integral part of the program.
B. Because precipitation events (precipitons) occur randomly across
the land surface grid through time
so no two model runs will have
identical precipitation histories.
14. Can WILSIM effectively model the degree of vegetation cover?
A. Partially, by decreasing the degree of erodibility under wetter
climates that would support a greater
protective vegetation cover.
B. Partially, by increasing the degree of erodibility under wetter
climates that would support a
greater protective vegetation cover.
C. No, there is no variable to simulate this in the model.
D. Yes, vegetation cover is implicitly modeled within WILSIM under
the climate constraints.
15. What do the hypsometric integrals as implemented in WILSIM tell
you about the drainage network and the elevation changes through time?
A. They give you an accurate hypsometry for specific drainage basins within
B. They can show the changes in elevation due to erosion through time for
specific drainage basin within the grid that has a uniform slope.
C. They can show the changes in elevation due to erosion and deposition through
time for a specific drainage basin.
D. They supply information on elevation change for erosion and deposition across
the entire grid. It does not measure individual basins nor does it account for
sediment transported off of the edge of the grid.