Overland runoff

A discussion forum for users of the new HYDRUS 2D/3D. HYDRUS is a software package for simulating water, heat and solute movement in two- and three-dimensional variably saturated media. Happy Posting!
Post Reply
galzk001
Posts: 4
Joined: Thu Apr 29, 2021 6:18 pm
Location: USA

Overland runoff

Post by galzk001 » Thu Apr 29, 2021 6:35 pm

I’m currently using Hydrus 2D v3.03 with the overland runoff module. I’m trying to determine how installation of solar panels will affect infiltration and overland runoff for 24 hr design storms. I’m trying to simulate a transect (attached) where runoff from an upslope panel (1) enters my domain as variable flux below the panel edge, between panels experiences regular precipitation (2), and under the downslope panel can be used for runoff infiltration. Is the overland module restricted to only my Atmospheric Boundary Condition of Precipitation? In other words, am I correct in assuming that whatever variable flux in zone (1) that doesn’t infiltrate is removed from the system as runoff and not routed down slope? I’d like to get panel runoff (1) to enter between panels along with precip (2) and also have overland runoff enter the downslope panel (3), but it seems overland runoff calculations don’t allow this type of flow routing? Does anyone have ideas on how I can simulate this?
Any help is greatly appreciated!
Attachments
solar_runoff.jpg
solar_runoff.jpg (68.84 KiB) Viewed 1126 times

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Overland runoff

Post by Jirka » Thu Apr 29, 2021 7:01 pm

The special Overland flow module of HYDRUS associates overland flow only with an Atmospheric boundary condition (Kode=-4). While the code allows treating the time-variable flux BCs (i.e., Kode=-3, -7, -8, and -9) as atmospheric BCs (i.e., with limited pressure head hCritA and hCritS), overland flux currently is not associated with these BCs. You thus cannot have two different boundary fluxes at a boundary with overland flow. The code also does not allow overland flow to continue on another part of the boundary without an atmospheric BC. That would require additional modifications of this special module. J.

galzk001
Posts: 4
Joined: Thu Apr 29, 2021 6:18 pm
Location: USA

Re: Overland runoff

Post by galzk001 » Fri May 07, 2021 1:13 pm

I'm wondering if I can solve this overland flow issue by running 2 domains separately. If I take the surface runoff generated in zone 2 where precip is occurring and use it as the atmospheric boundary condition input for zone 3 (no precip but receives surface runoff from zone 2), would this be a way to simulate the overland runoff being infiltrated down slope in a 2nd domain? I'm having trouble finding T-level print information for surface runoff (I'm used to Hydrus 1D that has a T_level.out file). Is the surface runoff printed to a file like it is in Hydrus 1D, or do I need to insert an observation point to determine surface runoff for my print times?

Thank you for the help!

galzk001
Posts: 4
Joined: Thu Apr 29, 2021 6:18 pm
Location: USA

Re: Overland runoff

Post by galzk001 » Fri May 07, 2021 3:17 pm

I found the runoff in the BalanceO.out file. If I distribute all of the runoff evenly over the 3rd zone as an atmospheric boundary condition, would this be an appropriate workaround to route runoff from one domain to the next? I don't know if I'm oversimplifying the overland runoff module or not. Thanks again for your help and suggestions!

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Overland runoff

Post by Jirka » Fri May 07, 2021 7:40 pm

If I recall, there should be several output files (Profile.out. Breakth.out, BalanceO.out) related to overland flow. They should be explained in the text about this special module.

What you suggest is something you could do with the current version. Alternatively, I could provide you with an updated version, which allows inflow into the domain using an inflow depth, h_inflow.

Also, if you send me the entire project, with upper boundary fluxes applied using atmospheric BC and time-variable fluxes, I could have a quick look, whether I could make it work for these other BCs. Although, I cannot guarantee that, since I do not have much time nowadays for new developments.

J.

galzk001
Posts: 4
Joined: Thu Apr 29, 2021 6:18 pm
Location: USA

Re: Overland runoff

Post by galzk001 » Mon May 10, 2021 3:52 pm

I would greatly appreciate if you could take a look, but please don't commit too much of your time.

Solar_runoff_1 represents the 3 boundary conditions in the above diagram: 1.Panel Runoff (var flux) 2.Precip (Atm BC) 3.Under Panel (no flux). Since I couldn't connect the overland runoff from the 1st BC to the 2nd, I created another file (solar_runoff_2) where panel runoff is evenly distributed across the entire Atm BC along with precip. This isn't exactly how the runoff would be distributed in the real world, but It was my workaround to connect the 1st and 2nd BC above. I will plan to simulate the 3rd BC as a separate domain to connect runoff from BC 2 to BC 3, but if you have a newer version that is able to connect the 2 with inflow and still simulate overland flow in over the 3rd BC, that would greatly simplify my analysis as I plan to run dozens of different slope and soil combinations.

Thanks!
Attachments
H3D3_solar_runoff_2.zip
(1.15 MiB) Downloaded 17 times
H3D3_solar_runoff_1.zip
(740.16 KiB) Downloaded 20 times

Jirka
Posts: 5268
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Overland runoff

Post by Jirka » Mon May 10, 2021 10:03 pm

It is highly unlikely that I will have time to look at this in the coming days/week. That’s more like a long-term project. J.

Post Reply