FLOOD09983

• County: Statewide
• Community: State of Colorado
• Stream Name: All
• Basin: Statewide
• Title: Mudflow A Two Dimensional Hyperconcentrated Sediment Flow-routing computer Model
• Date: 3/1/1989
• Prepared For: State of Colorado
• Prepared By: Simons Li & Associates Inc.
• Floodplain - Doc Type: Educational/Technical/Reference Information

3.13

3. If MUD, NERI, NFPI, NDC, NO DC is set equal to O.then the corresponding array
of data can be omitted from the data. NODC refers to the number of channel
grids, if NODC is 0, then all the channel data can be omitted from the data
file.

4. If MUD is equal to 0, then any sediment concentration information can be
omitted. If IUPMUD equals one for the watershed model, then MUD could be
either 0 or 1, zero if clear-water flo~IS are bein9 simu"lated.

5. A negative sign for the Manni ng' s n roughness va"1 ue shoul d be ass igned for
any flood plain grid element containin9 a channel.

6. If NODe is 0, then, NCHI, NPCHI, NCHO, NPCHO, NSTA, NPSTA and their associated
arrays are omitted.

""

7. If IUPMUD equal s 0, then ITI, NODEQP, and CCV (ITI) data are omi tted.

8. If a grid element (I) is a boundary elE!ment or if there is zero flow across
a gi ven boundary, then the appropri at.e FP{ I ,J) whel'e J = 1, 2, 3, or 4 is set
equal to O.

9. Time increment DTI and time decrement DTD values sl~lected by the user can be
modified to optimize the program. Typical values to compliment a selected
minimum time step DTMIN of one second might be DTI = 2 seconds and DTD = 3
seconds. A corresponding time step DTMAX might be 30 seconds. It is
suggested that the user experiment with these parameters.

10. If the program terminates because the minimum time step DTMIN is too largl~,
TOl, PTOl, and DTOlP can be varied to avoid altering DTMIN. Caution must be
exercised in revising these values because they effect the accuracy and detail
of the simulation.

11. The outflow boundaries for the flood plain are given by a critical flow
assumption.

q = 5.67 h1.5

(3.1 )

12. For the channel, the boundary flow condition may be established by either
critical depth outflow or by specifying a stage-discharge relationship given
by

Q=ahb (3.2)

where a and b must be input.

13. Output options include:

a. Suppressing all the input data being ~Iritten t.o the output file;
INPRINT = O.

b. The program will print all the out.put data for all the grid elements
unless otherwise specified. NOPRINT = 1 specifies that the outflow data
from the channel or flood plain outflow grids will not be printed. If