Eye4Software Hydromagic

  Hydrographic Survey Software

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Channel Design

After placing cross sections, as discussed in the previous chapter (Cross Sections),
we need to set the depth or elevation information of a couple of coordinates along the cross section.

These values are stored as pairs of distance and level data, where distance is the distance measured from the start of the line.

In order to create a theoretical DTM to be used in volume calculations, we need these values.

When the depth and the slope of the shore are known, it is possible to calculate depths on the cross sections automatically.

Calculating profiles

To alter a cross section's profile, just right click on the center anchor point, and select "Edit Section...". The following dialog ("Edit Cross Section") should now appear:

Edit cross section

When first editing a cross section, you will notice the graph display is empty, this is because no depths are stored by default. In this example, we will create a channel with a depth of 5 meters and a slope of 50 percent.

This means, that for each 2 meters, the bottom depth increases with 1 meter. When the bottom depth increases with 1 meter for each 4 meter extra distance from the shore, the slope is 25%. To calculate profiles from this setting, click the "Auto..." button. The following dialog should now appear:

Generate profiles

In the left section of the dialog, you can enter the channel design parameters, in the right section, you can select the cross sections you want to apply these parameters to. In this example, the depth at the shoreline should be half a meter, at the waterway axis, the depth should be 5 meters. The slope used is 50 percent. Click the "OK" button to apply these settings. The graph display will now look like this:

Edit Section Profile

You can check the other sections by browsing through them using the next and previous buttons.

Manual editing

In cases where calculation is not usable, for instance when a different slope is used on either sides,
or when a section is not placed between shores, you have to enter the distance and depth values manually.

To do so, click the "Edit..." button to open the profile editor:

Edit Section Profile

The table at the left of the dialog allows you to alter, insert and delete the distance-depth pairs if the profile.
Changes made, are directly visible in the graphical display. When done, just click "OK".

Checking the profiles

The quickest way of checking whether all profiles have been created correctly, is by creating a matrix view using the cross sections.
To do so, select the "Generate Matrix..." option from the "Sections" folder in the "Project Explorer".

Edit Section Profile

Select the correct boundary (in most cases the boundary used for auto placement of the sections), a file name for the matrix, and the spacing used (can be larger for a test, for volume calculation, use the same spacing as the matrix created from the sounding). Click "OK" and check the result.

Edit Section Profile