Parameter Analysis

[Yemima]

I am calibrating a SWAT model for 1 (one) basins with performed 28 simulations on a monthly.

However, I encountered challenges as my calibrated model produced unsatisfactory results, with R2 value of 0.4 and an NSE value of -1.02, indicating a poor fit between the observed value and simulated values. And also, the dotty not showed as well as the other literature (make a pattern).

To improve the calibration process and achieve more accurate results, I would greatly appreciate your guidance on selecting appropriate parameters and parameter ranges. I have included the parameters which I used in the basin.

Furthermore, I used SWAT-CUP and calibration In SUFI-2 from SWAT.TEMU.EDU.

1st iteration

Goal_type= Nash_Sutcliff    No_sims= 28     Best_sim_no= 20    Best_goal = 1.393902e-001

 Parameter_Name           Fitted_Value     Min_value      Max_value
1:R__CN2.mgt            -0.150000       -0.200000      0.200000
2:V__ALPHA_BF.gw        0.267857        0.000000       1.000000
3:V__GW_DELAY.gw        412.500000      30.000000      450.000000
4:V__GWQMN.gw           1.035714        0.000000       2.000000

2nd iteration

Goal_type= Nash_Sutcliff    No_sims= 28     Best_sim_no= 23    Best_goal = -3.286408e-001

 Parameter_Name           Fitted_Value     Min_value      Max_value
1:R__CN2.mgt            0.210714        0.200000       0.400000
2:V__GW_DELAY.gw        367.500000      30.000000      450.000000
3:R__SOL_AWC(..).sol    -0.121429       -0.200000      0.200000
4:V__ESCO.hru           0.226786        0.200000       0.500000

3rd iteration

Goal_type= Nash_Sutcliff    No_sims= 28     Best_sim_no= 5    Best_goal = -1.015049e+000

 Parameter_Name           Fitted_Value     Min_value      Max_value
1:R__CN2.mgt            0.525000        0.400000       0.600000
2:V__GW_DELAY.gw        172.500000      30.000000      450.000000
3:R__SOL_AWC(..).sol    -0.194643       -0.200000      0.100000
4:V__ESCO.hru           0.006250        -0.150000      0.200000