# TELEMAC-2D **URL:** https://opentelemac.org/forum/c/system-modules/telemac-2d/20.md [Latest](https://opentelemac.org/forum/latest.md) · [Categories](https://opentelemac.org/forum/categories.md) · [Tags](https://opentelemac.org/forum/tags.md) --- ## [About the TELEMAC-2D category](https://opentelemac.org/forum/t/about-the-telemac-2d-category/22)
**Author:** [@system](https://opentelemac.org/forum/u/system)\ **Replies:** 0\ **Last updated:** [October 20, 2026, 1:39pm UTC](https://opentelemac.org/forum/t/about-the-telemac-2d-category/22 "2026-10-20T13:39:50Z")
2D hydrodynamics simulations --- ## [boundary coniditions of flood inundation model](https://opentelemac.org/forum/t/boundary-coniditions-of-flood-inundation-model/8166)
**Author:** [@user\_16516](https://opentelemac.org/forum/u/user_16516)\ **Replies:** 0\ **Last updated:** [October 10, 2026, 3:42am UTC](https://opentelemac.org/forum/t/boundary-coniditions-of-flood-inundation-model/8166 "2026-10-10T03:42:47Z")
Hi \[name removed\], I am establishing a flood inundation model by telemac-2d. I am wondering how should I set the boundary conditions at the side of floodplain?(as shown the selected boundary in the photo) I want the wat… --- ## [Simulation of tracer trajectories in TelemacV8p4](https://opentelemac.org/forum/t/simulation-of-tracer-trajectories-in-telemacv8p4/8162)
**Author:** [@user\_17660](https://opentelemac.org/forum/u/user_17660)\ **Replies:** 0\ **Last updated:** [September 17, 2026, 6:57am UTC](https://opentelemac.org/forum/t/simulation-of-tracer-trajectories-in-telemacv8p4/8162 "2026-09-17T06:57:51Z")
Hello \[name removed\] telemac2d, I would like to simulate the trajectory of a particle starting at position (x0, y0) within the computational domain. Could you provide a reference subroutine? I tried using the example fr… --- ## [Outflow greater than Inflow](https://opentelemac.org/forum/t/outflow-greater-than-inflow/8157)
**Author:** [@user\_12549](https://opentelemac.org/forum/u/user_12549)\ **Replies:** 2\ **Last updated:** [September 3, 2026, 7:20am UTC](https://opentelemac.org/forum/t/outflow-greater-than-inflow/8157 "2026-09-03T07:20:47Z")
Hello, I have a simulation project consisting of an inflow, an outflow, and a weir located between them. I have performed multiple calculations by varying the weir dimensions and the number of weirs. However, in every c… --- ## [Weir type 2 in parallel mode](https://opentelemac.org/forum/t/weir-type-2-in-parallel-mode/8155)
**Author:** [@user\_1517](https://opentelemac.org/forum/u/user_1517)\ **Replies:** 3\ **Last updated:** [August 26, 2026, 8:43am UTC](https://opentelemac.org/forum/t/weir-type-2-in-parallel-mode/8155 "2026-08-26T08:43:05Z")
Dear \[name removed\], i’m trying to modify the subroutine calcul\_q\_weir.f on version V9.1 in order to define rules for mobile gates represented as weirs of type 2 on T2D. The management rules depend on the water level at… --- ## [Tracers that fail to advect](https://opentelemac.org/forum/t/tracers-that-fail-to-advect/8149)
**Author:** [@user\_12249](https://opentelemac.org/forum/u/user_12249)\ **Replies:** 1\ **Last updated:** [August 2, 2026, 6:53pm UTC](https://opentelemac.org/forum/t/tracers-that-fail-to-advect/8149 "2026-08-02T18:53:28Z")
Dear \[name removed\], I am currently running an SST tracer simulation in TELEMAC-2D, and I have encountered an issue with the tracer transport. The tracer does not appear to advect properly with the flow. Instead, it … --- ## [ASCII atmospheric data\_pressure](https://opentelemac.org/forum/t/ascii-atmospheric-data-pressure/8150)
**Author:** [@user\_18136](https://opentelemac.org/forum/u/user_18136)\ **Replies:** 7\ **Last updated:** [August 2, 2026, 5:47pm UTC](https://opentelemac.org/forum/t/ascii-atmospheric-data-pressure/8150 "2026-08-02T17:47:57Z")
Hello \[name removed\], I am a beginner user of Telemac2D. For a coastal flooding simulation, I wanted to add the option for atmospheric pressure variation (spatially constant) using an ASCII file. I consulted the user gu… --- ## [How to consider pressure in the example wind\_txy](https://opentelemac.org/forum/t/how-to-consider-pressure-in-the-example-wind-txy/7754)
**Author:** [@user\_17041](https://opentelemac.org/forum/u/user_17041)\ **Replies:** 3\ **Last updated:** [June 24, 2026, 3:27pm UTC](https://opentelemac.org/forum/t/how-to-consider-pressure-in-the-example-wind-txy/7754 "2026-06-24T15:27:12Z")
hello, I want to model wind and pressure values that time and space dependent The most suitable example for me was \[name removed\], and I want to consider the air pressure values in a similar way using this example I t… --- ## [Salinity diffusion in a hypersaline estuary](https://opentelemac.org/forum/t/salinity-diffusion-in-a-hypersaline-estuary/8130)
**Author:** [@user\_17855](https://opentelemac.org/forum/u/user_17855)\ **Replies:** 4\ **Last updated:** [May 8, 2026, 11:05pm UTC](https://opentelemac.org/forum/t/salinity-diffusion-in-a-hypersaline-estuary/8130 "2026-05-08T23:05:04Z")
Hello, I am a PhD student and am working with TELEMAC-2D on salinity in the Casamance estuary (Senegal), which is a dry-season hypersaline inverse estuary. During the dry season, upstream discharge is almost zero, and e… --- ## [Unable to see the element number for the negative determinant](https://opentelemac.org/forum/t/unable-to-see-the-element-number-for-the-negative-determinant/8094)
**Author:** [@user\_18878](https://opentelemac.org/forum/u/user_18878)\ **Replies:** 4\ **Last updated:** [May 8, 2026, 9:54pm UTC](https://opentelemac.org/forum/t/unable-to-see-the-element-number-for-the-negative-determinant/8094 "2026-05-08T21:54:19Z")
Hello, Im trying to simulate a dam breach along a river. I was able to get it to run and work how I wanted to with a rough mesh of 3m. However, when I make the fine smaller to get better results (1m) I am getting the er… --- ## [How to deal with thin dam/dike...](https://opentelemac.org/forum/t/how-to-deal-with-thin-dam-dike/828)
**Author:** [@user\_3454](https://opentelemac.org/forum/u/user_3454)\ **Replies:** 7\ **Last updated:** [May 8, 2026, 9:52pm UTC](https://opentelemac.org/forum/t/how-to-deal-with-thin-dam-dike/828 "2026-05-08T21:52:36Z")
Hi, I have a problem about the thin dam or dike. As having been described in Telemac 2D manual that it can handle weirs, whose width is comparable to its length and general grid size. And each weir is represented by… --- ## [OBSTACLE\_Closure](https://opentelemac.org/forum/t/obstacle-closure/8132)
**Author:** [@user\_18616](https://opentelemac.org/forum/u/user_18616)\ **Replies:** 1\ **Last updated:** [May 8, 2026, 9:49pm UTC](https://opentelemac.org/forum/t/obstacle-closure/8132 "2026-05-08T21:49:37Z")
I would like to know whether it is possible to include obstacle height in the obstacle\_closure approach. I am trying to simulate a permeable dike that is only partially submerged. I first tried using the obstacle option… --- ## [riv\_art example .pcl file empty](https://opentelemac.org/forum/t/riv-art-example-pcl-file-empty/8091)
**Author:** [@user\_11650](https://opentelemac.org/forum/u/user_11650)\ **Replies:** 2\ **Last updated:** [May 8, 2026, 9:45pm UTC](https://opentelemac.org/forum/t/riv-art-example-pcl-file-empty/8091 "2026-05-08T21:45:13Z")
I am running the riv\_art example, it generate the output drogues file of tecplot format without any problem. I tried then to output the .pcl format binary file, the .pcl file is empty. The .cas file is attached, all the… --- ## [Modeling of salinity (tracer) in a hypersaline estuary with low flow](https://opentelemac.org/forum/t/modeling-of-salinity-tracer-in-a-hypersaline-estuary-with-low-flow/8124)
**Author:** [@user\_17855](https://opentelemac.org/forum/u/user_17855)\ **Replies:** 3\ **Last updated:** [April 26, 2026, 3:56pm UTC](https://opentelemac.org/forum/t/modeling-of-salinity-tracer-in-a-hypersaline-estuary-with-low-flow/8124 "2026-04-26T15:56:08Z")
Hello \[name removed\], My name is \[name removed\], and I’m a Ph.D. student at La Rochelle University (France). I’m currently working on modeling saltwater intrusion in a hypersaline estuary (46–50 psu at 115 km fro… --- ## [wastewater discharge dispersion](https://opentelemac.org/forum/t/wastewater-discharge-dispersion/8128)
**Author:** [@user\_16418](https://opentelemac.org/forum/u/user_16418)\ **Replies:** 2\ **Last updated:** [April 26, 2026, 2:09pm UTC](https://opentelemac.org/forum/t/wastewater-discharge-dispersion/8128 "2026-04-26T14:09:53Z")
Hello \[name removed\] all TELEMAC2D users, I have developed a model for the dispersion of discharges into the receiving environment. After running the simulation, I do not observe any dispersion at the discharge points. … --- ## [Couplage Tomawac Telemac2d?](https://opentelemac.org/forum/t/couplage-tomawac-telemac2d/8125)
**Author:** [@user\_16418](https://opentelemac.org/forum/u/user_16418)\ **Replies:** 2\ **Last updated:** [April 26, 2026, 2:06pm UTC](https://opentelemac.org/forum/t/couplage-tomawac-telemac2d/8125 "2026-04-26T14:06:30Z")
Hello \[name removed\], I carried out a study on the dispersion of wastewater discharge concentration into the sea using a coupling of Telemac2D and Tomawac. When I activate WAVE DRIVEN CURRENTS = YES, Telemac2D gives the… --- ## [Open Ocean Tide Oscillations Despite Boundary and Mesh Adjustments](https://opentelemac.org/forum/t/open-ocean-tide-oscillations-despite-boundary-and-mesh-adjustments/8100)
**Author:** [@user\_12448](https://opentelemac.org/forum/u/user_12448)\ **Replies:** 1\ **Last updated:** [April 26, 2026, 12:46pm UTC](https://opentelemac.org/forum/t/open-ocean-tide-oscillations-despite-boundary-and-mesh-adjustments/8100 "2026-04-26T12:46:53Z")
Hi, I’m running a China Sea tidal simulation using TELEMAC-2D, ranging from 15-40°N, 105-144°E，forced by TPXO8 tide level prediction. The initial free surface field is smooth and reasonable as provided by TPXO SATEL… --- ## [Best practices and configurations for estuary modelling TELEMAC2D](https://opentelemac.org/forum/t/best-practices-and-configurations-for-estuary-modelling-telemac2d/8129)
**Author:** [@user\_18401](https://opentelemac.org/forum/u/user_18401)\ **Replies:** 1\ **Last updated:** [April 26, 2026, 11:47am UTC](https://opentelemac.org/forum/t/best-practices-and-configurations-for-estuary-modelling-telemac2d/8129 "2026-04-26T11:47:01Z")
Hi \[name removed\] everyone, I kinda new on TELEMAC 2D however, I know about hydrodynamics principles in surface-ocean continuum. I would like to know if you have some recommendations for my project. I am created an estu… --- ## [Wier modelling in Telemac 2D](https://opentelemac.org/forum/t/wier-modelling-in-telemac-2d/8123)
**Author:** [@user\_18285](https://opentelemac.org/forum/u/user_18285)\ **Replies:** 1\ **Last updated:** [April 26, 2026, 10:50am UTC](https://opentelemac.org/forum/t/wier-modelling-in-telemac-2d/8123 "2026-04-26T10:50:17Z")
How can we include a wier within the computational mesh and how to prescribe the boundary condition in Telemac 2D. --- ## [modelling bridge piers impacts using USER\_DRAGFO](https://opentelemac.org/forum/t/modelling-bridge-piers-impacts-using-user-dragfo/8118)
**Author:** [@user\_11650](https://opentelemac.org/forum/u/user_11650)\ **Replies:** 1\ **Last updated:** [April 26, 2026, 10:46am UTC](https://opentelemac.org/forum/t/modelling-bridge-piers-impacts-using-user-dragfo/8118 "2026-04-26T10:46:57Z")
Hi \[name removed\], Has anyone modelled the impacts of bridge piers or similar vertical structures without building them into the grid, for example using using the USER\_DRAGFO.f or any other way? I did not find much info… --- ## [unknown keyword 'computation continued'](https://opentelemac.org/forum/t/unknown-keyword-computation-continued/8061)
**Author:** [@user\_16357](https://opentelemac.org/forum/u/user_16357)\ **Replies:** 3\ **Last updated:** [April 26, 2026, 9:57am UTC](https://opentelemac.org/forum/t/unknown-keyword-computation-continued/8061 "2026-04-26T09:57:11Z")
Dear \[name removed\], I’m building a 2D coupled model between Telemac2D and GAIA. When I run the steering file in my personal computer, which includes the keyword ‘COMPUTATION CONTINUED’, it can run successfully. Howeve… --- ## [Wetting and drying in a lake model with water level fluctuations](https://opentelemac.org/forum/t/wetting-and-drying-in-a-lake-model-with-water-level-fluctuations/8117)
**Author:** [@user\_12215](https://opentelemac.org/forum/u/user_12215)\ **Replies:** 7\ **Last updated:** [April 10, 2026, 8:05am UTC](https://opentelemac.org/forum/t/wetting-and-drying-in-a-lake-model-with-water-level-fluctuations/8117 "2026-04-10T08:05:01Z")
Hej, I’m working on a lake model, where the water level is fluctuating up to a difference in water level of 2m. The model takes the tributaries and the outflows into consideration. As the lake itself is rather small (1… --- ## [tide at the downstream boundary and the flood at the upstream](https://opentelemac.org/forum/t/tide-at-the-downstream-boundary-and-the-flood-at-the-upstream/7749)
**Author:** [@user\_18396](https://opentelemac.org/forum/u/user_18396)\ **Replies:** 9\ **Last updated:** [March 31, 2026, 7:42am UTC](https://opentelemac.org/forum/t/tide-at-the-downstream-boundary-and-the-flood-at-the-upstream/7749 "2026-03-31T07:42:23Z")
Hello \[name removed\], I am working on a project to model a river that opens into the Atlantic in northern Brittany, France. For this, I need to take into account the tide at the downstream boundary and the flood hydrogr… --- ## [Spatially and temporally varying water levels at the boundary](https://opentelemac.org/forum/t/spatially-and-temporally-varying-water-levels-at-the-boundary/8111)
**Author:** [@user\_9386](https://opentelemac.org/forum/u/user_9386)\ **Replies:** 1\ **Last updated:** [March 18, 2026, 6:29am UTC](https://opentelemac.org/forum/t/spatially-and-temporally-varying-water-levels-at-the-boundary/8111 "2026-03-18T06:29:54Z")
I have water levels for all the nodes at the boundary. I want to give it in liquid boundary file and run the simulation. How can I do that? --- ## [weir](https://opentelemac.org/forum/t/weir/7977)
**Author:** [@user\_18812](https://opentelemac.org/forum/u/user_18812)\ **Replies:** 11\ **Last updated:** [January 26, 2026, 3:32pm UTC](https://opentelemac.org/forum/t/weir/7977 "2026-01-26T15:32:24Z")
Hi \[name removed\], I would like to ask you, when dealing with the weir module, I choose the first type of horizontal weir. I would like to ask about the numbering of the underlined part in the picture. What should this n… --- ## [Issue Integrating .i2s Obstacle Polygons—TELEMAC(Main) version](https://opentelemac.org/forum/t/issue-integrating-i2s-obstacle-polygons-telemac-main-version/8087)
**Author:** [@user\_18616](https://opentelemac.org/forum/u/user_18616)\ **Replies:** 2\ **Last updated:** [November 27, 2025, 5:21pm UTC](https://opentelemac.org/forum/t/issue-integrating-i2s-obstacle-polygons-telemac-main-version/8087 "2025-11-27T17:21:12Z")
I am able to successfully run the official TELEMAC example for obstacles, but I am facing issues when applying the same procedure in my own model. The simulation runs without errors, but it completely ignores the obstacl… --- ## [The parallel computation failed](https://opentelemac.org/forum/t/the-parallel-computation-failed/8008)
**Author:** [@user\_18706](https://opentelemac.org/forum/u/user_18706)\ **Replies:** 4\ **Last updated:** [November 5, 2025, 2:26pm UTC](https://opentelemac.org/forum/t/the-parallel-computation-failed/8008 "2025-11-05T14:26:27Z")
I installed Telemac v8p5 in a Linux environment, and then I ran the command python -m telemac2d xqh.cas --ncsize=4 to perform parallel computing. I encountered the following error: At line 136 of file /home/slf/TELEMAC/… --- ## [Diffusion coefficient issue with multiple sources](https://opentelemac.org/forum/t/diffusion-coefficient-issue-with-multiple-sources/7976)
**Author:** [@user\_17721](https://opentelemac.org/forum/u/user_17721)\ **Replies:** 3\ **Last updated:** [October 23, 2025, 9:33pm UTC](https://opentelemac.org/forum/t/diffusion-coefficient-issue-with-multiple-sources/7976 "2025-10-23T21:33:34Z")
Hello, I am working on a 2D model (v8p0) with 12 source points and 1 tracer, coupled with WAQTEL - DEGRADATION LAW. The contaminant I am simulating is fecal coliform bacteria. The variables I am calibrating are T90 (fir… --- ## [Velocity Issue in a Tidal Flat Simulation](https://opentelemac.org/forum/t/velocity-issue-in-a-tidal-flat-simulation/7973)
**Author:** [@user\_18194](https://opentelemac.org/forum/u/user_18194)\ **Replies:** 2\ **Last updated:** [October 23, 2025, 9:26pm UTC](https://opentelemac.org/forum/t/velocity-issue-in-a-tidal-flat-simulation/7973 "2025-10-23T21:26:57Z")
Hello \[name removed\], I’m encountering persistent problems with my tidal channel simulation, specifically regarding velocity errors that appear randomly when low tide conditions expose tidal flats. I’ve consulted the ma… --- ## [Initial Condition: user\_condin\_h.f and free surface](https://opentelemac.org/forum/t/initial-condition-user-condin-h-f-and-free-surface/8037)
**Author:** [@user\_17382](https://opentelemac.org/forum/u/user_17382)\ **Replies:** 1\ **Last updated:** [October 23, 2025, 5:46pm UTC](https://opentelemac.org/forum/t/initial-condition-user-condin-h-f-and-free-surface/8037 "2025-10-23T17:46:19Z")
Hi \[name removed\], i’m trying to model a dam break with flooding of the surrounding areas. To initiate the model I want to have water in the river but not in surrounding areas that are below the riverbed. As far as i u… [Next page](https://opentelemac.org/forum/c/system-modules/telemac-2d/20.md?page=1)