I have an estuarine stream with marshes. We have kept the main channel to one cell wide and have added cells along the sides at discrete locations. These marsh cells all have bed elevations that are higher than the channel cell they to which they are connected (i.e., marsh is -0.4 m and channel cell is -5 m). There are many times where the channel will have water surface elevation that is 0.5 m or more higher than the marsh bed elevation, but no water flows into the marsh. I have wetting/drying turned on with 0.02 (W) and 0.01 (D) m specified. The effect appears to be random with respect to cell sizes. Some cells don’t have any problems, while others never or almost never get water moving into them. Any thoughts on possible issues?Orthogonality for the grid ranges from -2.98 to 2.96.Thank you
Hey Tom,I have the Wetting & Drying flag set to -11, the Dry Depth set to 0.01, the Dry Step set to 0, and the BC Wet Depth set to 0.02.
HI John,How did you set the initial water condition? Sometimes it is not good to assign all the same water level initially.
Hi,All cells are initially set to the same level initially. I have a period of at least 15 days of run time to let the system stabilize before my target time period. I will try to run with a variable water level through the system as an initial condition.
I tried two model runs. The first used a variable water surface based on the results later in the model for the same tidal stage. The model is starting on an ebb tide, so a good number of the marsh cells are dry to begin with using this method. The results seem to be worse visually with more cells staying empty, but I have not extracted the data to compare for sure.The second used the water surface elevation at the same level, giving all cells water to begin. The dry step was changed from 0 to 1. It appears that this is better than using the variable water level to start, but there are still marsh cells that do not fill.
Tom,I’m using Version 7.2. I have Version 8(not sure which right now) available, but I’m collaborating with a State Agency that is not going to upgrade on their own, so I’m stuck using 7.2. I will send the files to the reference e-mail.Thank you,John Michael
What value do you have set for Dry Step in Wetting & Drying options?
You might also try setting your Dry Step to a value greater than or equal to 1.
Hi John,This is indeed a strange problem you are encountering.Can you tell me what version of EFDC_Explorer and EFDC+ you are using? We made some improvements to the wetting and drying algorithm in EFDC_Explorer version 8.3 and 8.4, so if you are using an older version you might consider upgrading if you have a subscription license.If you are open to it, you can also send your model (excluding output files) to support@eemodelingsystem.com for us to have a look. If it’s a bug we will fix it, and if not we can help get to the bottom of the problem.Thank you,Tom
What value do you have set for Dry Step in Wetting & Drying options?
You might also try setting your Dry Step to a value greater than or equal to 1.
Hi John,This is indeed a strange problem you are encountering.Can you tell me what version of EFDC_Explorer and EFDC+ you are using? We made some improvements to the wetting and drying algorithm in EFDC_Explorer version 8.3 and 8.4, so if you are using an older version you might consider upgrading if you have a subscription license.If you are open to it, you can also send your model (excluding output files) to support@eemodelingsystem.com for us to have a look. If it’s a bug we will fix it, and if not we can help get to the bottom of the problem.Thank you,Tom