• ### Re: How Can I solve floating point division by zero error?

Dear Dipen,

Thank you for the print screen. Apparently, the problem is generated by the instability of the model. I observed that you have many warnings which indicate strong oscillation in the model. My opinion is that the eror "Floating point division by zero" is just a consequence of the instabilities.

Recommendations:
1. Analyse the results file (it should cover 67% of simulation period) and try to identify the problems here;
1. Check out the geometry of the cross sections and the junctions between branches;
2. Try smaller time steps for simulation: 1 min, 30 sec, even 5 sec;

Best regrds,
Aurelian

• ### Re: How Can I solve floating point division by zero error?

Hello,

Can you give us more details about the model and the context of the error ? What modules of Mike 11 are activated in the model ? When do the errors occur? Can you attach a print-screen of the error ?

Kind regards,
Aurelian
• ### Re: Lower boundary condition as free outflow?

Hi,

In your case, the best practice, from my point of view, is to follow the next steps:
1. If the very downstream sector is important for your study, extend your model in the downstream part with 2-3 Km (with real data, if you have it, or even with some plausible date). The reason is that the last sector upstream the downstream boundary condition is strongly influenced by this condition.
2. Open the Simulation file (mandatory), open from here the editor of the boundary condition file -> Select the row with downstream boundary condition -> than go to Tools (menu) -> "Auto Calculation of H-Q Table..." -> Choose Manning Formula and fill in the fields Slope and Manning's M values with average values used in the downstream sector.
3. Now, a calculated Q-h relationship for your downstream boundary condition is set up.

Kind Regards,
Aurelian
• ### Re: Processed Hydraulic Radii must be positive

Hi,

I think the problem is that the X column (cumulative distance) was not computed (at all). Because there is no reason to start a cumulative distance array with 187458 m, instead of starting with 0.

Kind regards,
Aurelian
• ### Re: Processed Hydraulic Radii must be positive

Hello Laura,

This type of error sometimes happens. It could be caused by geometry of the cross section. Can you export the cross section as raw data for this location (MAIN BRANCH', chainage 2000.00 m) and upload the file here? To export a cross-section, select it by double clicking on it's chainage (in the left tree view), than, go to File -> Export Selected Sections -> Export Raw Data... .

Kind regards,
Aurelian

• ### Re: Error 69

Hi,

Have you checked the processed data at the chainage 0 meter on KHUNIN1 river ? Pay attention at hydraulic radius and try to correct it if it's not correct. This section seems to play the role of boundary for the model, so please check up the boundary condition, too.

Regards,
Aurelian
• ### Re: Floodplain

Hello Doan,

I'm glad that you fixed the error. Sure I'll try to help you and other Mike users in the future.

Regarding the last question: no, I'm not a member of DHI. I worked as research assistant at Technical University of Civil Engineering of Bucharest for many years and we used DHI software suit for activities such as hydrological and hydraulic modeling.

Kind regards,
Aurelian
• ### Re: Floodplain

Hello Doan,

Have you checked the processed data for the cross-section located at FLOODPLAIN 2: 0.000 meter ? Also, there are some tips about how to set up the link channel. Can you provide more details about your project (purpose of the model, relevant print-screens from your Mike setup, why you was forced to made up the floodplain geometry or any other information to clarify the context and solve the error) ?

Kind regards,
Aurelian
• ### Re: .omi file

Hi Jiwaszko,

The *.omi file is a configuration file used by Mike software in oder to use OpenMI (Open Modelling Interface).  OpenMI is an open IT-standard that facilitates linking of hydrological models and modules (Gregersen, 2007). For example, you can use OpenMI to link a river network modeled in Mike 11 and a groundwater model made in Sobek.

More details about OpenMI here: http://www.openmi.org/
More about how Mike11 and OpenMI work together: http://www.jennylestil.com/docs/openMI.pdf

Kind regards,
Aurelian
• ### Re: Initial conditions

Hi Mahsa,

The initial condition must be set for entire 1D model of the river network, not only for "(upstream) as local values". You have to set up a general value to be applied for the whole system of branches and other values for specific sectors, if the case.

Also, you have to understand the distinction between "Water level" and "Water depth" for the field Level type and chose the apropriate value (eg. Water depth = 1 m as a global value and Water level = 132.40 m (could be a normal retention level) for a specific sector of a certain river where a reservoir is located - please, see the image attached.

Kind Regards,
Aurelian