3.4 Drainage Analysis
Overview: The Drainage Analysis functionality allows you to calculate various useful surface drainage characteristics such as:
- Ponding Depth Map,
- Catchment Area and flow direction arrows.
analysis assumes enough rainfall occurs to overflow all depressions in the
field. Ponding is the water that cannot drain away by flowing along the ground
surface, so it needs to infiltrate or evaporate to be removed. Currently the results are for the existing
topographic surface. Applying this analysis to the ‘proposed topographic
surface’ will be possible in future OptiSurface Designer versions.
Menu: Tools> Drainage Analysis...
Calculation Grid: The cell spacing of the grid that the drainage analysis is calculated on. 10m is a typical useful value.
Furrow or Beds Restrict Water Flow Direction: If furrows or beds exist tick this on.
Furrow/Beds Height (m): The height of the intended furrows in the field. The water will build up in any depressions and then spill across the furrow.Furrow/Beds Bearing (deg): The direction of the furrows relative to north. Use the ‘Pick’ button to click two points to define the direction or type a number in.