Overland and Pipe flow

Hi,

I am quite new with MU. I am preparing a model with both OF and pipe network. However, I am unable to delineate sub catchments based on the two types of network. Actually, I have a catchment with 626 ha area. It has OF and more than 1500 manhole and around 800 catchpits. Can anyone guide me which methodology I should adapt to prepare the final model?
All the guidance would be highly appreciated.

Regards

Hi,
Perform the following steps.
1. Delineate catchments with Catchpits first and then further delineate them with manholes if water from surface is also entering through manholes in the system.
2. To run the overland flow model, couple the manholes/catchpits with the surface. You can read about all the properties which need to be defined in OF flow model in Collection system manual.
3. To add the boundary condition, you can either add this in 2D overland flow model or with the catchments.
4. Run the project check tool after each steps.

Let me know if you require any more clarifications on this.

/Mohit 

Hi Mohit,

Thanks for your response. Regarding #1; how can we delineate catchments within previously delineated catchments? What I was trying to do previously was treating catchpits as manhole and the delineating catchments for all of them. However, I do not think that is appropriate technique.
Now what I understood is I can dra surface and subsurface manhole and their corresponding open channel and pipe networks. Then I can join them together to perform 1D model.
Am I right?

Regards.
Saleem

Hi Saleem,
Perform the following steps to delineate catchments.
1. First, delineate catchments with manholes on DEM. This can also be done in ArcGIS.
2. Once you have delineated/imported the bigger catchments, Try delineating/breaking them through theissen polygon method with Catch pit layer. This is also done through delineating wizard but the only difference is you have to select the existing catchment layer as boundary polygon.
3. After performing this you have to make some correction in catchments as this will make some gaps in the catchment layer.

Whether you should first delineate catchments with catch pit layer or manhole layer, this depends on how equally distributed your catch pits/manholes are.

Med vänlig hälsning
Mohit

Thanks Mohit.
I will try the same then will let know if got any confusion.
Regards

I have a lot of information.