3.4.7.1 Subzones
Last Updated: 29 July 2020 For: OptiSurface Designer V2+
Overview:
Subzones can apply different design parameters to different areas within a boundary zone. Where a subzone exists and parameters are defined, that value will overwrite the design
parameters of the boundary zones. The design parameters are mapped onto the
calculation grid points that fall within that subzone. Subzones can overlap
each other. Where they overlap, their ranking in the priority list defines
which design parameter is actually sent to the OptiSurface Calculation Engine.
These settings tell the OptiSurface
Calculation Engine what characteristics or properties the proposed design
surface should have.
Displayed
by:
Menu: Tools > New Design Zone
Toolbar:
Subzone Type
- Normal: This is the default subzone type when you draw a subzone. It can apply different design parameters to the calculation grid points that fall within that subzone. For more details on the parameters, see 3.4.7 Landform Design.
- Valley:
This is a special type of subzone used to guide water to flow to a
desired direction. It can also apply different design parameters.
Note: The valley subzone should extend to just outside the boundary
zone. Only effective when used OptiSurface 2Way and OptiSurface 4Way.
- Ridge:
This is a special type if subzone that behaves like a barrier,
preventing water to flow to the subzone. It can also apply different
design parameters. Note: The ridge subzone should ideally extend to
just outside the boundary zone and go back from one side of the boundary
to the other to work well. Only effective when used OptiSurface 2Way
and OptiSurface 4Way.
- Exclusion: Points inside this subzone are not included in the calculation of the landform design. OptiSurface treats this area as a boundary, therefore allows drainage into the subzone.
- Inflow: Used for Runoff Analysis. Adds an inflow from a watershed going into the field.
The valley subzones represent the infield drains and is recommended to be perpendicular (or approach a perpendicular) to the Main Slope direction. In cases where the infield drain will be parallel to the Main Slope direction, an Exclusion (pink) subzone can be used instead of a valley zone.
See below the initial landform design calculation.
Subzone Parameters
- Max. Cross/Main Slope Ratio: Defines the ratio of cross slope to main slope of
any calculation grid point covered by the subzone.
- Max. Allowable Elevation (m or ft): Defines the maximum elevation of any calculation grid point covered by the subzone.
- Min.
Allowable Elevation (m or ft): Defines the minimum elevation of
any
calculation grid point covered by the subzone.
- Min. Cut (m or ft): Defines the minimum depth of soil that can be removed (cut) from any grid point covered by the subzone.
- Max. Cut (m or ft): Defines the maximum depth of soil that can be removed (cut) from any grid point covered by the subzone.
- Min. Fill (m or ft): Defines the minimum depth of soil that can be removed (cut) from any grid point covered by the subzone.
- Max. Fill (m or ft): Defines the maximum depth of soil that can be added (filled) an any grid point covered by the subzone.
Subzone Net Earthworks
- Balance Earthworks: Ticking this will
balance the earthworks within the subzone when Fill to Import and Cut to
Export are set to zero. Note: The earthworks within the boundary zone
is the master balance for the boundary and any balancing within subzones
are nested within the boundary. For example, if the boundary zone
balances to zero import or export but a subzone has an import of 1000 m3
then the areas outside the subzone but inside the boundary will
contribute 1000 m3 of cut into the subzone. So, the subzone is like a
sub-balance as well, i.e. it is not a separate balance.
- Fill to Import (m3 or yd3):
Defines the volume of soil to bring into the subzone boundary area to
the field boundary area. This volume is taken into account when
balancing earthworks to the cut/fill ratio.
- Fill to Export (m3 or yd3): Defines the volume of soil to remove from the subzone boundary area to the field boundary area. This volume is taken into account when balancing earthworks to the cut/fill ratio.