Description of a sedflux river file

The river file specifies river characteristics of the river as it enters the model domain. It can come in two formats: key-value file (ASCII), or Hydrotrend (binary). Regardless of format, the river format specifies river width, depth, velocity, and concentrations of each of the grain types. In both cases, if sedflux runs through all of the periods of your river file, it will return to the beginning.

Key-value File

The user can specify river characteristics key-value pairs for an arbitrary number of time periods. Unlike the Hydrotrend file, these time periods need not be the same length. The following example defines two periods:

[ 'Season 1' ]
Duration (y):                            3m
Bedload (kg/s):                          300.0
Suspended load concentration (kg/m^3):   6,      3,      3,      3
velocity (m/s):                          1.0
Width (m):                               100.0
Depth (m):                               5.0
[ 'Season 2' ]
Duration (y):                            9m
Bedload (kg/s):                          30.0
Suspended load concentration (kg/m^3):   .6,      .3,      .3,      .3
velocity (m/s):                          1.0
Width (m):                               10.0
Depth (m):                               .5

The first period lasts for 3 months, and the second for 9 months (the periods do not need to sum to 1 year - they can be whatever length you like).

There are a couple of things to note about this file:

• The above river file describes five grain types - one bedload type and four suspended load types. It is necessary that the number of grain types given here are the same number described in the sediment file In addition, the order that they are listed here (starting with bedload) corresponds to the order that they are listed in the sediment file.
• The durations that you specify in this file will override the time step that you provided in the initialization file. Thus, say you provided a time step of 1 day in the initialization file. If using the above river file, this time step would be ignored and would instead alternate between 3 months and 9 months.

Hydrotrend File

The Hydrotrend model can output daily, monthly, or yearly river data. See the Hydrotrend web page for a detailed description of the format. One thing to note though is that it is binary and will be of the byte-order of the machine that it was created on. It has been a common problem for users to use a Hydrotrend file created on one machine but then run sedflux with this file on a machine with the opposite byte-order. sedflux should now be able to notice this and give an appropriate error message.