Fig. 6. Evolution of the best (minimum) root mean square error (RMSE) values as a function of the number of HYDRUS-1D model evaluations with the NSGA-II and MOSCEM-UA algorithms and AMALGAM: (a) compromise solution RMSE0, (b) best fit for 0.4-m depth RMSE1, (c) best fit for 1.0-m depth RMSE2, and (d) best fit for 2.6-m depth RMSE3. Single-objective SCE-UA runs are also separately included.