Creation of FLO2D Grid System

1
Setting FLO-2D components/attributes in GDS
2
FLO-2D component input

• Mannings n
• Streets
• Channels
• Buildings (ARF/WARF)
• Levees
• Infiltration parameters

3
GDS imports/creates/edits these files

• Required
• FPLAIN.DAT
• CADPTS.DAT
• CONT.DAT
• TOLER.DAT
• Optional
• INFLOW.DAT
• OUTFLOW.DAT
• ARF.DAT
• CHAN.DAT
• INFIL.DAT
• STREET.DAT
• XSEC.DAT

4
Select Grid Elements

• There are two ways to edit grid element
  attributes or components
• Double click on a grid element
• Use the Select and Assign Values to Selection
  options on the Grid Menu
• Selection can be polygon based

5
Streets

• click in a street grid element
• Edit the street on the selected element

6
Streets (creation)

• Click Create Street en command in Tools menu
• Drag mouse to delineate street.
• Double click to finish street.
• The group of selected elements forms a street.

7
Streets (editing)

• Click Edit Street Parameters command

8
Buildings Area and Width Reduction factors
ARF/WRF
9
ARF

• ARF (Area Reduction Factor) is used to simulate
  the reduced storage volume of a grid element due
  to the presence of buildings and other obstacles

10
WRF

• WRF (Width Reduction Factor) is used to simulate
  the blocking effect caused by walls and other
  obstacles on a grid element.

11
Levees

• Levees can be used to isolate portions of the
  floodplain as levees, berms, roadway, railroad
  embankments, etc.
• Levee data requirements include
• Grid element number, levee crest elevation,
  cutoff flow direction

12
Levee Failure

• Levees can fail by overtopping or by being
  inundated at prescribed elevation for a specified
  duration
• Fail to a prescribed elevation different from the
  floodplain elevation
• Specify levee breach width
• Specify a rate of failure both vertically and
  horizontally

13
Levee Failure Options
Levee failure width
Levee crest elevation
Vertical failure rate
Horizontal failure rate
Levee failure base elevation
Floodplain elevation
14
Levee Output

• LEVEE.OUT - contains a list of the grid elements
  with a levee that failed. Failure width, failure
  elevation, discharge from the levee breach and
  the time of failure are listed.
• LEVOVERTOP.OUT Contains the overtopping
  discharge hydrograph for all elements with levee
  being overtopped. The combined discharge for all
  the levee overtopping directions within the grid
  element is summed and written to this file.

15
(No Transcript)
16
Multiple Channel Component

• Simulate the overland flow in rills and gullies
  rather than as overland sheet flow
• Accounts for gullies that can not be resolved by
  at the scale of the grid element size
• Simulating rill and gully flow concentrates the
  discharge and improves the timing of overland
  runoff routing.
• The gully geometry is defined by a maximum depth,
  width and flow roughness.
• Multiple channel attributes can be spatially
  variable on the grid system and can be edited.

17
Multiple Channel Component

• Overland flow occurs within the grid element to
  the rill or gully. Flow between the grid
  elements occurs only in the gullies.

18
(No Transcript)
19
Whats next?

• Flood Hydrology