## Drainage Network

MOHID Land forum. Questions and discussion related to MOHID Land
ceciletheodore@acceptablesavenirs.eu
MOHID Beginner
Posts: 9
Joined: Thu Jan 01, 1970 00:00

### Drainage Network

Hi everybody,

Looking at drainage network module, there are few different Downstream_Boundaries listed in the wiki and I would like to have some more explanations about their significations...Especially, I do not understand what does mean : Critical Depth condition.

Thanks,

Cécile

Jauch
Posts: 98
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hi Cecile

ceciletheodore@acceptablesavenirs.eu
MOHID Beginner
Posts: 9
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Ok, thanks Eduardo!

Cécile

frank.maretec@ist.utl.pt
MOHID Guru
Posts: 151
Joined: Thu Jan 01, 1970 00:00
Location: Technical University of Lisbon
Contact:

### Re: Drainage Network

Dear Cecile,

you have four options for the downstream boundary.

DOWNSTREAM_BOUNDARY : 0 -> Dam. No water passes
DOWNSTREAM_BOUNDARY : 1 -> Zero depth gradient. Slope of the last reach remains constant. Works bad if you are using hydrodynamic aprox 2 or 3
DOWNSTREAM_BOUNDARY : 2 -> Critical Depth. Flow leaves the last reach with critical flow (area of the upstream node * Sqrt (g * h))
DOWNSTREAM_BOUNDARY : 3 -> Downstream water level is constant
DOWNSTREAM_BOUNDARY : 4 -> Downstream velocity is constant. Flow is calculated from area

For normal cases I recomend option 2

Hope this helps,

Frank
In order to understand recursivity you must first understand recursivity.

ceciletheodore@acceptablesavenirs.eu
MOHID Beginner
Posts: 9
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Thanks Frank,

It helps a lot!

Cécile

ceciletheodore@acceptablesavenirs.eu
MOHID Beginner
Posts: 9
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hi everyone!

Back to this topic... Sorry... But I tried to run a simulation with the third BOUNDARY CONDITION : imposed water level and I had an error message.. So I think , I am doing something wrong in defining this parameter.

So in Drainage Network Data File:
NETWORK_FILE : ..\General Data\Digital Terrain\Drainage Network.dnt
GLOBAL_MANNING : 0.025
MIN_WATER_DEPTH : 0.0001
DISCHARGES : 1
HYDRODYNAMIC_APROX : 3 !1 - KinematicWave. 2 - DiffusionWave. 3 - DynamicWave
DOWNSTREAM_BOUNDARY : 3 !0 - Dam. 1 - ZeroDepthGradient. 2 - CriticalDepth. 3 - ImposedWaterLevel. 4 - ImposedVelocity
DEFAULT_VALUE : 65.0 !Imposed downstream value
STABILIZE : 1
STABILIZE_FACTOR : 0.05
TIME_STEP_SPLIT : 1

And then, I have this error message :
-------------------- DRAINAGE NETWORK --------------------

Number of Nodes : 8192
Number of Reaches : 8191
Number of Outlets : 1
Hydrodynamic Approx. : Dynamic Wave
Numerical Scheme : ExplicitScheme
Downstream Boundary : Imposed water level

Inconsistent River Network 348 3
CheckRiverNetWorkConsistency - ModuleRunOff – ERR02

Could you explain me how to impose a waterlevel or a velocity?

Best regards,

Cécile

frank.maretec@ist.utl.pt
MOHID Guru
Posts: 151
Joined: Thu Jan 01, 1970 00:00
Location: Technical University of Lisbon
Contact:

### Re: Drainage Network

Dear Cecile,

The error you get does not have anything to do with the downstream boundary conditions. It states that there is a mismatch between the DrainageNetwork you are using and the DrainageNetwork you obtained during basin delineation. This usually occurs in two cases:
1. Your basin geometry file is not match the parameters you used when you generated the drainage network (location of the outlet and Treshold area)
2. You changed your DTM after you generated the drainage network.

Concerning the Downstream Boundary Condition:
I have been working "hard" on the Drainage Network Downstream Boundary Condition. The present version of MOHID at mohid.codeplex.com has many correction, but you have to compile it...

The version you are using, do not work very well with imposed levels, if you have huge flooding. Currently I'm testing the new version and I will release a new compiled version as soon as possible. If you run into trouble, I recommend that you use:
DOWNSTREAM_BOUNDARY : 2
This options works well. But you can also try the imposed value (it's not bad at all in your version).

Hope this helps,
Frank
In order to understand recursivity you must first understand recursivity.

ceciletheodore@acceptablesavenirs.eu
MOHID Beginner
Posts: 9
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Many thanks Frank!

epelde.ane@gmail.com
Posts: 172
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hello all,
I wanted to start a simulation with some flow in the network, and I guessed that the keyword I had to change is INITIAL_WATER_DEPTH in the drainage network module, but I´m not sure..
There is no ploblem when it is set to 0.0, but when I give a value to this parameter, it appears an error (I´ve tried with 0.3, 1 and 2, taking into account that the minimum depth of the defined cross sections is 0.7m). Let me know please if I´m wrong, but isnt this a constant value for all the network?
Thanks

davidbrito
Posts: 187
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hello Ane,

the initial water level is that. a initial value of water depth for all the nodes. then it will try to compute flows from there.

What is the error?

David

epelde.ane@gmail.com
Posts: 172
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hello all

I found the following error when I tried to make longer a simulation (it was ok for 4 days, but when I set it of 2 months it run for many hours and then it appeared this):

forrtl: severe (172): Program Exception - exception code = 0x2b4 (692) Image PC Routine Line Source
MOHIDLand_release 0051A2DC _MODULEDRAINAGENE 8279 ModuleDrainageNetwork.F90
MOHIDLand_release 00519938 _MODULEDRAINAGENE 8173 ModuleDrainageNetwork.F90
MOHIDLand_release 00516C76 _MODULEDRAINAGENE 7196 ModuleDrainageNetwork.F90
MOHIDLand_release 0051645C _MODULEDRAINAGENE 7047 ModuleDrainageNetwork.F90
MOHIDLand_release 004E5F64 _MODULEBASIN_mp_D 4722 ModuleBasin.f90
MOHIDLand_release 004DDBC8 _MODULEBASIN_mp_M 2878 ModuleBasin.f90
MOHIDLand_release 004F1A4F _MAIN__ 73 MohidLand.f90
MOHIDLand_release 00822BA3 Unknown Unknown Unknown
MOHIDLand_release 0077BA4C Unknown Unknown Unknown
kernel32.dll 77221114 Unknown Unknown Unknown
ntdll.dll 7730B299 Unknown Unknown Unknown
ntdll.dll 7730B26C Unknown Unknown Unknown

So, I guess that it is related to the drainage network but I dont know how to work it out.. I tried with the soucecode but nothing..

Thanks,

garbossa@gmail.com
MOHID Beginner
Posts: 12
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hello epelde.ane,

I had the same error for the same reason. When I run for one day it works just fine. When I extend it for 2 days it gives an error similar to yours.

forrtl: severe (172): Program Exception - exception code = 0x2b4 (692) Image PC Routine Line Source
.
.
.

If anyone can help

Best regards,

LHP Garbossa

davidbrito
Posts: 187
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hello All

Is this still a issue?

Since we worked together with Ane and this was not appearing.
If it still appears we need should se what options are using and what kind of simulation.

David

garbossa@gmail.com
MOHID Beginner
Posts: 12
Joined: Thu Jan 01, 1970 00:00

### Re: Drainage Network

Hello All,

No, it is not an issue anymore. I had a problem on harmonics and water level...

Regards!

Garbossa