Sebastian Schwindt @ Hydro-Morphodynamics channel on YouTube.

``` Compare the results of the dry and wet model initializations with regard to the following questions: * How does the mass balance evolve during the simulation? * How long did the simulations take to converge and did you need to modify the `NUMBER OF TIME STEPS`? * How reasonable are the results (double-check with the above comment)? * Which of the two initial conditions would you use in practice to show that the simulation is correct? (tm2d-calibration)= # 2d Calibration Parameters ```{dropdown} Recall: How to calibrate? Calibration involves the step-wise adaptation of model input parameters to yield a possibly best (statistic) fit of modeled and measured data. In the process of model calibration, only one parameter should be modified at a time by 10 to 20-% deviations from its default value. For instance, if the beginning `FRICTION COEFFICIENT : 0.03`, the calibration may test for `FRICTION COEFFICIENT : 0.033`, then `FRICTION COEFFICIENT : 0.036`, `FRICTION COEFFICIENT : 0.027` and so on, ultimately to find out which value for **FRICTION COEFFICIENT** brings the model results closest to observations. Moreover, a sensitivity analysis compares step-wise modifications of multiple parameters (still: one at a time) and theirs effect on model results. For instance, if a 10-% variation of **FRICTION COEFFICIENT** yields a 5-% change in global water depth while a 10-% variation of grid size (edge length) yields a 20-% change in global water depth, it may be concluded that the model sensitivity is higher with respect to the grid size. However, such conclusions require careful considerations in multi-parametric, complex models of river ecosystems. ``` The following parameters may be used for calibrating a 2d model to measurements (e.g., water surface elevation, water depth, or flow velocity data): * **FRICTION COEFFICIENT** ({ref}`friction section