ERROR: Groundwater below UZ column

Hi! I've been working with a integrated model for MIKE SHE, where I try to combine the SZ and UZ. I have unfortunately had a bit of trouble because my model stops at 7.8% each time (preprocessing is always successful). Unfortunately, I do not really know how to solve the problem. The message I get is:

ERROR: Groundwater below UZ column in point ( 46 140)
depth to groundwater: 19.75 m (level 273.84 m)
max depth of column : 19.75 m (soil profile no. 1)
nrpd,m1,lbot,accprdepth(lbot,m1), accprdepth(lbot+1,m1):
0        1            1            19.75000000000 
19.75000000000

I'm a student and is rather new at working with MIKE SHE and appreciate all the help I can get!

Thank you so much in advance!

Best regards

Elin

Increase the thickness (depth) of UZ column so that when water table recedes it doesn't go below the specified UZ depth. There should be a specified UZ to simulate the unsaturated flow but the model doesn't see it when the water table drops below your specified UZ depth and gives an error.

Hi Elin,
I can add some more detail to this.
The UZ model will stop if the water table falls below the bottom of the UZ model.

However, the UZ model only couples to the top SZ layer, and the top SZ layer never completely dries out.
So the safest way to define the UZ is to define UZ layers down to the bottom of SZ Layer 1. In this case, a falling water table will never cause the UZ model to stop - even if the water table falls into the 2nd SZ layer.

There is no practical penalty for doing this. If the water table remains high, the UZ cells that are saturated contribute to the size of the UZ output file, but they don't slow down the simulation.

Regards,
Douglas

Thank you for the help! That solved my problem! :)

Hi Mr. Graham,

I am with the same problem that Elin, my model also stop with the ERROR: Groundwater below UZ column in point.
I understand that UZ layers must be define down to the bottom of SZ layer 1, but I could know how do that.
How I define UZ layers down SZ layer 1?

I will appreciate all the help I can get!

Thank you in advance!

Best regards,

Lara