Hi everyone! I am facing the same problem, in the exactly same subroutine (NMINRL line 194). I´ve checked the fortran code of NMINRL of line 194:
194> sut = .1 + .9 * Sqrt(sol_st(kk,j) / sol_fc(kk,j))
The problem appears when it calculates the squared root of "sol_st(kk,j) / sol_fc(kk,j)". Since sol_st(kk,j) is aways set to a value higher than 0 on line 193, the problem is the "sol_fc(kk,j)", that could be zero or negative.
193> if (sol_st(kk,j) < 0.) sol_st(kk,j) = .0000001
The "sol_fc" is calculated in the subroutine "biozone":
biozone.f(38): !! sol_fc(:,:) |mm H2O |amount of water available to plants in soil
biozone.f(177): sol_fc(bz_lyr,j)=bz_thk(j)*(sol_up(bz_lyr,j)-sol_wp(bz_lyr,j))
biozone.f(200): sol_fc(bz_lyr,j) = sol_fc(bz_lyr,j) + coeff_fc1(j) *
biozone.f(201): & (sol_ul(bz_lyr,j) - sol_fc(bz_lyr,j)) ** coeff_fc2(j)
and is a function of the soil input data:
bz_thk(:) |mm |thickness of biozone
sol_up(:,:) |mm H2O/mm soil|water content of soil at -0.033 MPa (field capacity)
sol_wp(:,:) |mm H20/mm soil|water content of soil at -1.5 MPa (wilting point)
coeff_fc1(:) |none |field capacity calibration parameter 1
So, the only way that sol_fc is set to 0 or a negative value, would be a "bz_thk x sol_up" equal or lower than "sol_wp".
In other words, the problem should be that the thickness of the layer multiplied by the field capacity is lower than the wilting point.
However I checked my soil data, and everything looks nice. I even tried to use land use and soil parameters from the default database to check if the problem was really in the input data, but it still does not runs. I also corrected the soil maps so they have 100% coverage.
Please, if someone knows what else to do to correct this error, let me know!
Cheers!