MODFLOW Zone Budget

[julian.weir]

Hi. Has anybody had any issues with MODFLOW's zone budget? I am running a very simple model in GSM v 7.0. The model is multilayer with constant heads all equal to the initial conditions. This results in all water levels being the same in all layers, and all flat. Model layers and land surface are all flat too. I run a transient model with no pumping or recharge (no stresses at all) and predicted water levels are flat (as expected).

However, the zone budget reports significant changes in storage in the upper layer. Ins and Outs are misbalanced too. I would expect small calculation errors, but the errors returning are quite large. Has anybody else come across this or have any suggestions for correcting? Is it a zone budget bug? Different solvers and different iteration criteria make little difference. Thanks in advance.

[mmamobile]

I'm having trouble with Zonebudget as well - when I convert zones created using the conceptual model approach to MODFLOW, the entire Zonebudget zone matrix is removed from the grid menu entirely.

I've tried to manually copy + paste, but the matrix seems to reset itself to a uniform value of 1 even after saving. This is version 7.0.2.

[julian.weir]

I have the same re-setting issue. When the project is closed and then re-opened, GMS will reset all zones to a default of 1. GMS advised that it is a bug, and they are currently working on fixing it. Though I understand that the problem in my 1st post isn't related to this.

Edited January 5, 2010 by julian.weir