Demonstrations and Experiments
24
© 2012 Little River Research & Design; updated July 2018
Some basic guidelines for using the Emriver are included here. Further instructions and exercises can be
found in the
Emriver Lab Manual
.
Demonstrations and Experiments
The primary independent variables imposed on your experimental channels are channel slope and
discharge. To gain familiarity with the capabilities of the model, it is best to begin by exploring both of
these variables at relatively low values.
Slope is controlled by the slope of the box (which is 6% when you use the support horses on a level
surface) and by the elevation of the standpipe. Slope of your channels is also dependent, of course, on
their sinuosity. It is best to begin with lower slopes. A small laser level can be used to explore the
relative elevations of the upper end of the channel and the standpipe. The modeling media is
manufactured within a range of specifications and its specific gravity can vary from batch to batch. This
may cause slightly different sediment behavior in different models.
As you are learning to use the model, begin with low flows (about 25 ml/s, as seen in Figure 24, left
side). These flows may seem too low at first glance, but low flows often give the most interesting
results. Higher flows (about 125 ml/sec, shown in Figure 24, right side) will mobilize all sediment in the
channel, which, in many demonstrations and experiments, will make it difficult to see specific processes.
Try forming a channel with moderate flows (less than 75 ml/s), and then lowering flow to find the point
at which sediment transport in the channel ceases. Work up from this point.
Figure 24. Low flow (left) and high flow (right) as it appears when looking at
the EDU.
