Does LAK automatically suppress RCH and EVT when lake cells are wet?
F TW
Hi all,
We are modelling seasonal pools (which appear in the wet season and vanish in the dry) and want to use RCH, EVT, and LAK without predefining the shifting pool borders. To avoid double-counting, our intended setup is:
- RCH active everywhere (represents areal recharge).
- LAK rainfall set to 0.0 (so no double-count with RCH).
- EVT always active with vegetation ET = A.
- LAK evaporation adds the
“open-water minus vegetation” increment = B.
- When a cell is wet (LAK active): total ET = A + B = open-water ET.
- When dry (no LAK): ET = A only.
We were told that in MF6, when a LAK cell is wet, RCH and EVT are automatically suppressed for the underlying (vertical connected) aquifer cell. We couldn’t find this in the docs/examples, so we built a minimal iMOD Python test (quite a lot of work for a test):
- Case 1 (LAK wet, with LAK rainfall+evap): expect RCH and EVT suppressed.
- Case 2 (LAK dry): expect RCH/EVT active.
Result: In the cell beneath a wet LAK cell, RCH and EVT fluxes are the same as in a non-lake cell, NO suppression observed in the CBC. This suggests no automatic switching between LAK and RCH/EVT.
Questions:
1. Is there an official reference showing that LAK should suppress RCH and EVT in underlaying connected cell when a lake cell is wet?
2. If such switching exists, how is it enabled / specified?
Otherwise, our split-ET approach above seems appropriate.
Thanks in advance, Martin
Richard Winston
--
This group was created in 2004 by Mr. C. P. Kumar, Former Scientist 'G', National Institute of Hydrology, Roorkee. Please visit his webpage at https://www.angelfire.com/nh/cpkumar/
---
You received this message because you are subscribed to the Google Groups "MODFLOW Users Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to modflow+u...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/modflow/f898b0f6-a176-48cd-901d-c0a39f7fcc90n%40googlegroups.com.