subroutine nut_orgnc !! ~ ~ ~ PURPOSE ~ ~ ~ !! this subroutine calculates the amount of organic nitrogen removed in !! surface runoff !! ~ ~ ~ INCOMING VARIABLES ~ ~ ~ !! name |units |definition !! ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ !! enratio |none |enrichment ratio calculated for day in HRU !! erorgn(:) |none |organic N enrichment ratio, if left blank !! |the model will calculate for every event !! ihru |none |HRU number !! ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ !! ~ ~ ~ ~ ~ ~ END SPECIFICATIONS ~ ~ ~ ~ ~ ~ use organic_mineral_mass_module use hru_module, only : hru, ihru, sedorgn, sedyld, enratio use soil_module implicit none integer :: j = 0 !none |HRU number real :: xx = 0. !kg N/ha |amount of organic N in first soil layer real :: wt1 = 0. !none |conversion factor (mg/kg => kg/ha) real :: er = 0. !none |enrichment ratio real :: conc = 0. ! |concentration of organic N in soil real :: xx1 = 0. ! | j = ihru !! HRU calculations xx = soil1(j)%tot(1)%n + rsd1(j)%tot(1)%n + rsd1(j)%man%n wt1 = soil(j)%phys(1)%bd * soil(j)%phys(1)%d / 100. if (hru(j)%hyd%erorgn > .001) then er = hru(j)%hyd%erorgn else er = enratio end if conc = xx * er / wt1 sedorgn(j) = .001 * conc * sedyld(j) / hru(j)%area_ha !! update soil nitrogen pools only for HRU calculations if (xx > 1.e-6) then xx1 = (1. - sedorgn(j) / xx) soil1(j)%tot(1)%n = soil1(j)%tot(1)%n * xx1 rsd1(j)%tot(1)%n = rsd1(j)%tot(1)%n * xx1 rsd1(j)%man%n = rsd1(j)%man%n * xx1 end if return end subroutine nut_orgnc