Water levels at sea - beach - island, only under influence of tide - Forum - iMOD
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Water levels at sea - beach - island, only under influence of tide
M. vdW, modified 3 Years ago.
Water levels at sea - beach - island, only under influence of tide
Youngling Posts: 17 Join Date: 7/5/21 Recent Posts
Hello all,
We probably all know Tutorial 5, 'Create your First Groundwater Flow Model' (modelling an island).
Additional to this model, I would like to simulate the effect of the tide on the groundwater AND surface water levels.
The attached scheme visualizes the case and belonging data.
In this case, I ignored seasonal influence and the influence of the fresh water lens under the island, i.e. I assumed that the groundwater level at the island is only influenced by the tide.
At the sandy beach, the seawater and groundwater levels rise equally, but the seawater level lowers quicker than the groundwater level. This effect diminishes towards the center of the island.
Question
Which modules/packages should I use to model the beach and island's surface water level and groundwater levels (only under influence of tide, including the described effect)?
Answer
TOP, BOT, BND, SHD, KHV, KVA, KVV, RCH, ???, ???, ???, ???
Thanks in advance!
Martin
We probably all know Tutorial 5, 'Create your First Groundwater Flow Model' (modelling an island).
Additional to this model, I would like to simulate the effect of the tide on the groundwater AND surface water levels.
The attached scheme visualizes the case and belonging data.
In this case, I ignored seasonal influence and the influence of the fresh water lens under the island, i.e. I assumed that the groundwater level at the island is only influenced by the tide.
At the sandy beach, the seawater and groundwater levels rise equally, but the seawater level lowers quicker than the groundwater level. This effect diminishes towards the center of the island.
Question
Which modules/packages should I use to model the beach and island's surface water level and groundwater levels (only under influence of tide, including the described effect)?
Answer
TOP, BOT, BND, SHD, KHV, KVA, KVV, RCH, ???, ???, ???, ???
Thanks in advance!
Martin
Frans Roelofsen, modified 3 Years ago.
RE: Water levels at sea - beach - island, only under influence of tide
Padawan Posts: 51 Join Date: 11/11/13 Recent Posts
Hi Martin,
The most simple option is to add the CHD package (constant head). Your model will be transient: you add the rise and fall of the water level over time to the model (the Storage package must be added to) . Use the iMOD Project Manager to add your CHD parameters to the PRJ file both as grid value (IDF) or single value. You can fill the package manually from the GUI. Their are also some tricks to create and add timeseries of values to the PRJ file in a more automated way.
Read a bit more about this package in chapter 12 of the manual (https://oss.deltares.nl/web/imod/online-imod-user-manual).
Kind regards,
Frans
The most simple option is to add the CHD package (constant head). Your model will be transient: you add the rise and fall of the water level over time to the model (the Storage package must be added to) . Use the iMOD Project Manager to add your CHD parameters to the PRJ file both as grid value (IDF) or single value. You can fill the package manually from the GUI. Their are also some tricks to create and add timeseries of values to the PRJ file in a more automated way.
Read a bit more about this package in chapter 12 of the manual (https://oss.deltares.nl/web/imod/online-imod-user-manual).
Kind regards,
Frans
M. vdW, modified 3 Years ago.
RE: Water levels at sea - beach - island, only under influence of tide
Youngling Posts: 17 Join Date: 7/5/21 Recent Posts
Hello Frans,
Thank you for your answer.
I applied CHB and STO to layer 1, 2 and 3 of the ISLAND model to simulate tide with seawater levels at 0.0, +0.7, +1.0, +0.7, 0.0, -0.7, -1.0, -0.7, 0.0 m MSL.
(Applying CHB and STO only to layer 1 led to an error.)
See the result in the attached image.
Question 1: When choosing Tplanes in 3D Tool, I would expect that the play knobs (forward, backward, play forward, play backwards, stop) would work (similar as they work when Tvoxels is chosen). Is this possible? I cannot find an explanation in the manual nor the Forum.
Question 2: With CHD at 15 m (the maximum height of the island elevation), I would expect the island to submerge and that all heads would be 15 m. However, this is not what the model shows: the seawater is not flooding the island. How can this be modelled? Perhaps by defining BND and CHD for each tide elevation (e.g. tide level is +1.0, BND is also at this elevation)?
Question 3: How to model run off during the period high tide to low tide?
Question 4: How to keep layer 1 unconfined when using the Model Type ‘iMOD Runfile’? The setting (Simulation Manager, Layers/ Packages, Model Layers settings, Layer 1, Convertible (HNEW-BOT)) is not stored in the RUN file.
Thanks in advance again.
Martin
Thank you for your answer.
I applied CHB and STO to layer 1, 2 and 3 of the ISLAND model to simulate tide with seawater levels at 0.0, +0.7, +1.0, +0.7, 0.0, -0.7, -1.0, -0.7, 0.0 m MSL.
(Applying CHB and STO only to layer 1 led to an error.)
See the result in the attached image.
Question 1: When choosing Tplanes in 3D Tool, I would expect that the play knobs (forward, backward, play forward, play backwards, stop) would work (similar as they work when Tvoxels is chosen). Is this possible? I cannot find an explanation in the manual nor the Forum.
Question 2: With CHD at 15 m (the maximum height of the island elevation), I would expect the island to submerge and that all heads would be 15 m. However, this is not what the model shows: the seawater is not flooding the island. How can this be modelled? Perhaps by defining BND and CHD for each tide elevation (e.g. tide level is +1.0, BND is also at this elevation)?
Question 3: How to model run off during the period high tide to low tide?
Question 4: How to keep layer 1 unconfined when using the Model Type ‘iMOD Runfile’? The setting (Simulation Manager, Layers/ Packages, Model Layers settings, Layer 1, Convertible (HNEW-BOT)) is not stored in the RUN file.
Thanks in advance again.
Martin
Frans Roelofsen, modified 3 Years ago.
RE: Water levels at sea - beach - island, only under influence of tide
Padawan Posts: 51 Join Date: 11/11/13 Recent Posts
Hi Martin, :
- The Tplanes method should not be part of the selection options. While it is not (yet) developed. Only the Tvoxel is described in the manual. Perhaps 4D viewing will be part of the iMOD6 release for which Deltares develops an additional 3D viewer .
- questions 2 an 3 are more about modelling concepts and ways how to model in Modflow. Those quesionts I leave to the forum or to your colleagues to assist you on. .
- calculation with unconfined layers is only possible in Modflow2005 and Modflow6. According to the iMOD manual on the RUN file route: "All aquifers are confined, unconfinedness is supported via the NAM-file export mode only’
Kind regards,
Frans
- The Tplanes method should not be part of the selection options. While it is not (yet) developed. Only the Tvoxel is described in the manual. Perhaps 4D viewing will be part of the iMOD6 release for which Deltares develops an additional 3D viewer .
- questions 2 an 3 are more about modelling concepts and ways how to model in Modflow. Those quesionts I leave to the forum or to your colleagues to assist you on. .
- calculation with unconfined layers is only possible in Modflow2005 and Modflow6. According to the iMOD manual on the RUN file route: "All aquifers are confined, unconfinedness is supported via the NAM-file export mode only’
Kind regards,
Frans