Residence time on semi-closed lagoons https://dlt-acc.firelay.cloud/c/message_boards/find_thread?p_l_id=4041874&threadId=4391887 2026-05-12T16:51:47Z 2026-05-12T16:51:47Z Georgenes Cavalcante https://dlt-acc.firelay.cloud/c/message_boards/find_message?p_l_id=4041874&messageId=4391886 2021-07-07T09:36:16Z 2021-07-07T09:36:16Z

Hi,<br /><br />I am developing a model to study the residence time inside a semi-closed lagoon. I have done the model using the fractions data and set 1 to the area of interest and 0 to the domain. I know we can check the concentration changing within the internal area over time, but I was trying to generate an output to verify the age of the tracer over time. So, I would have both the concentration map and also another map showing age variability.<br /><br />I actually tried to set up a conservative tracer and the corresponding decayable tracer with the same initial and concentrations and a decay rate of 0.01. However, as I am only interested in the lagoon area, this method requires setting the concentration to either 1 or 100 for initial and bnd. The simulation gives the age for the entire domain, which is not what I want. I also tried drawing a polygon over the lagoons and set the value to 100 and 0 outside, keeping the bnd to 100 (it doesn&#39;t run when set to 0), but it mixes both tracers. <br /><br />I am not sure if it can be done or for residence time studies, we have to use the fraction methods.<br />   <br /> I really appreciate all suggestions and clarifications.<br /> <br />Geórgenes

Georgenes Cavalcante 2021-07-07T09:36:16Z