hhwatqual.f

水文模型的原始代码

         nh3con = (ammoin * wtrin + ammonian(jrch) * hrchwtr(ii))       &
     &                                                          / wtrtot
         no2con = (nitritin * wtrin + nitriten(jrch) * hrchwtr(ii))     &
     &                                                          / wtrtot
         no3con = (nitratin * wtrin + nitraten(jrch) * hrchwtr(ii))     &
     &                                                          / wtrtot
         orgpcon = (orgpin * wtrin + organicp(jrch) * hrchwtr(ii))      &
     &                                                          / wtrtot
         solpcon = (dispin * wtrin + disolvp(jrch) * hrchwtr(ii))       &
     &                                                          / wtrtot
         cbodcon = (cbodin * wtrin + rch_cbod(jrch) * hrchwtr(ii))      &
     &                                                          / wtrtot
         o2con = (disoxin * wtrin + rch_dox(jrch) * hrchwtr(ii))        &
     &                                                          / wtrtot
         else
         algcon = (algin * wtrin + halgae(ii-1) * hrchwtr(ii)) / wtrtot
         orgncon = (orgnin * wtrin + horgn(ii-1) * hrchwtr(ii)) / wtrtot
         nh3con = (ammoin * wtrin + hnh4(ii-1) * hrchwtr(ii)) / wtrtot
         no2con = (nitritin * wtrin + hno2(ii-1) * hrchwtr(ii)) / wtrtot
         no3con = (nitratin * wtrin + hno3(ii-1) * hrchwtr(ii)) / wtrtot
         orgpcon = (orgpin * wtrin + horgp(ii-1) * hrchwtr(ii)) / wtrtot
         solpcon = (dispin * wtrin + hsolp(ii-1) * hrchwtr(ii)) / wtrtot
         cbodcon = (cbodin * wtrin + hbod(ii-1) * hrchwtr(ii)) / wtrtot
         o2con = (disoxin * wtrin + hdisox(ii-1) * hrchwtr(ii)) / wtrtot
         end if

         !! calculate temperature in stream
         !! Stefan and Preudhomme. 1993.  Stream temperature estimation 
         !! from air temperature.  Water Res. Bull. p. 27-45
         !! SWAT manual equation 2.3.13
         wtmp = 0.
         wtmp = 5.0 + 0.75 * tmpav(jrch)
         if (wtmp <= 0.) wtmp = 0.1

         !! calculate effective concentration of available nitrogen
         !! QUAL2E equation III-15
         cinn = nh3con + no3con

         !! calculate saturation concentration for dissolved oxygen
         !! QUAL2E section 3.6.1 equation III-29
         ww = 0.
         xx = 0.
         yy = 0.
         zz = 0.
         ww = -139.34410 + (1.575701e05 / (wtmp + 273.15))
         xx = 6.642308e07 / ((wtmp + 273.15)**2)
         yy = 1.243800e10 / ((wtmp + 273.15)**3)
         zz = 8.621949e11 / ((wtmp + 273.15)**4)
         soxy = Exp(ww - xx + yy - zz)
         if (soxy < 0.) soxy = 0.
!! end initialize concentrations

!! O2 impact calculations
        !! calculate nitrification rate correction factor for low
        !! oxygen QUAL2E equation III-21
        cordo = 0.
        cordo = 1.0 - Exp(-0.6 * o2con)
        !! modify ammonia and nitrite oxidation rates to account for
        !! low oxygen
        bc1mod = 0.
        bc2mod = 0.
        bc1mod = bc1(jrch) * cordo
        bc2mod = bc2(jrch) * cordo
!! end O2 impact calculations

         !! calculate flow duration
         thour = 0.
         thour = hhtime(ii)
         if (thour > 1.0) thour = 1.0
         thour = 1.0

!! algal growth
         !! calculate light extinction coefficient 
         !! (algal self shading) QUAL2E equation III-12
         if (ai0 * algcon > 1.e-6) then
           lambda = lambda0 + (lambda1 * ai0 * algcon) + lambda2 *      &
     &                                        (ai0 * algcon) ** (.66667)
         else
           lambda = lambda0
         endif

         !! calculate algal growth limitation factors for nitrogen
         !! and phosphorus QUAL2E equations III-13 & III-14
         fnn = 0.
         fpp = 0.
         fnn = cinn / (cinn + k_n)
         fpp = solpcon / (solpcon + k_p)

         !! calculate hourly, photosynthetically active,
         !! light intensity QUAL2E equation III-9c
         !! Light Averaging Option # 3
         algi = 0.
         algi = frad(hru1(jrch),ii) * hru_ra(hru1(jrch)) * tfact 

         !! calculate growth attenuation factor for light, based on
         !! hourly light intensity QUAL2E equation III-6a
         fll = 0.
         fll = (1. / (lambda * hdepth(ii))) *                           &
     &    Log((k_l + algi) / (k_l + algi * (Exp(-lambda * hdepth(ii)))))

         !! calculcate local algal growth rate
         gra = 0.
         select case (igropt)
           case (1)
             !! multiplicative QUAL2E equation III-3a
             gra = mumax * fll * fnn * fpp
           case (2)
             !! limiting nutrient QUAL2E equation III-3b
             gra = mumax * fll * Min(fnn, fpp)
           case (3)
             !! harmonic mean QUAL2E equation III-3c
             if (fnn > 1.e-6 .and. fpp > 1.e-6) then
               gra = mumax * fll * 2. / ((1. / fnn) + (1. / fpp))
             else
               gra = 0.
             endif
         end select

         !! calculate algal biomass concentration at end of day
         !! (phytoplanktonic algae)
         !! QUAL2E equation III-2
         halgae(ii) = 0.
         halgae(ii) = algcon + (Theta(gra,thgra,wtmp) * algcon -        &
     &    Theta(rhoq,thrho,wtmp) * algcon - Theta(rs1(jrch),thrs1,wtmp) &
     &                                    / hdepth(ii) * algcon) * thour
         if (halgae(ii) < 0.) halgae(ii) = 0.

         !! calculate chlorophyll-a concentration at end of day
         !! QUAL2E equation III-1
         hchla(ii) = 0.
         hchla(ii) = halgae(ii) * ai0 / 1000.
!! end algal growth 

!! oxygen calculations
         !! calculate carbonaceous biological oxygen demand at end
         !! of day QUAL2E section 3.5 equation III-26
         yy = 0.
         zz = 0.
         yy = Theta(rk1(jrch),thrk1,wtmp) * cbodcon
         zz = Theta(rk3(jrch),thrk3,wtmp) * cbodcon
         hbod(ii) = 0.
         hbod(ii) = cbodcon - (yy + zz) * thour
         if (hbod(ii) < 0.) hbod(ii) = 0.

         !! calculate dissolved oxygen concentration if reach at 
         !! end of day QUAL2E section 3.6 equation III-28
         uu = 0.
         vv = 0.
         ww = 0.
         xx = 0.
         yy = 0.
         zz = 0.
         uu = Theta(rk2(jrch),thrk2,wtmp) * (soxy - o2con)
         vv = (ai3 * Theta(gra,thgra,wtmp) - ai4 *                      &
     &                                  Theta(rhoq,thrho,wtmp)) * algcon
         ww = Theta(rk1(jrch),thrk1,wtmp) * cbodcon
         xx = Theta(rk4(jrch),thrk4,wtmp) / (hdepth(ii) * 1000.)
         yy = ai5 * Theta(bc1mod,thbc1,wtmp) * nh3con
         zz = ai6 * Theta(bc2mod,thbc2,wtmp) * no2con
         hdisox(ii) = 0.
         hdisox(ii) = o2con + (uu + vv - ww - xx - yy - zz) * thour
         if (hdisox(ii) < 0.) hdisox(ii) = 0.
!! end oxygen calculations

!! nitrogen calculations
         !! calculate organic N concentration at end of day
         !! QUAL2E section 3.3.1 equation III-16
         xx = 0.
         yy = 0.
         zz = 0.
         xx = ai1 * Theta(rhoq,thrho,wtmp) * algcon
         yy = Theta(bc3(jrch),thbc3,wtmp) * orgncon
         zz = Theta(rs4(jrch),thrs4,wtmp) * orgncon
         horgn(ii) = 0.
         horgn(ii) = orgncon + (xx - yy - zz) * thour
         if (horgn(ii) < 0.) horgn(ii) = 0.

        !! calculate fraction of algal nitrogen uptake from ammonia
        !! pool QUAL2E equation III-18
        f1 = 0.
        f1 = p_n * nh3con / (p_n * nh3con + (1. - p_n) * no3con +       &
     &                                                            1.e-6)

        !! calculate ammonia nitrogen concentration at end of day
        !! QUAL2E section 3.3.2 equation III-17
        ww = 0.
        xx = 0.
        yy = 0.
        zz = 0.
        ww = Theta(bc3(jrch),thbc3,wtmp) * orgncon
        xx = Theta(bc1mod,thbc1,wtmp) * nh3con
        yy = Theta(rs3(jrch),thrs3,wtmp) / (hdepth(ii) * 1000.)
        zz = f1 * ai1 * algcon * Theta(gra,thgra,wtmp)
        hnh4(ii) = 0.
        hnh4(ii) = nh3con + (ww - xx + yy - zz) * thour
        if (hnh4(ii) < 0.) hnh4(ii) = 0.

        !! calculate concentration of nitrite at end of day
        !! QUAL2E section 3.3.3 equation III-19
        yy = 0.
        zz = 0.
        yy = Theta(bc1mod,thbc1,wtmp) * nh3con
        zz = Theta(bc2mod,thbc2,wtmp) * no2con
        hno2(ii) = 0.
        hno2(ii) = no2con + (yy - zz) * thour
        if (hno2(ii) < 0.) hno2(ii) = 0.

        !! calculate nitrate concentration at end of day
        !! QUAL2E section 3.3.4 equation III-20
        yy = 0.
        zz = 0.
        yy = Theta(bc2mod,thbc2,wtmp) * no2con
        zz = (1. - f1) * ai1 * algcon * Theta(gra,thgra,wtmp)
        hno3(ii) = 0.
        hno3(ii) = no3con + (yy - zz) * thour
        if (hno3(ii) < 0.) hno3(ii) = 0.
!! end nitrogen calculations

!! phosphorus calculations
        !! calculate organic phosphorus concentration at end of
        !! day QUAL2E section 3.3.6 equation III-24
        xx = 0.
        yy = 0.
        zz = 0.
        xx = ai2 * Theta(rhoq,thrho,wtmp) * algcon
        yy = Theta(bc4(jrch),thbc4,wtmp) * orgpcon
        zz = Theta(rs5(jrch),thrs5,wtmp) * orgpcon
        horgp(ii) = 0.
        horgp(ii) = orgpcon + (xx - yy - zz) * thour
        if (horgp(ii) < 0.) horgp(ii) = 0.

        !! calculate dissolved phosphorus concentration at end
        !! of day QUAL2E section 3.4.2 equation III-25
        xx = 0.
        yy = 0.
        zz = 0.
        xx = Theta(bc4(jrch),thbc4,wtmp) * orgpcon
        yy = Theta(rs2(jrch),thrs2,wtmp) / (hdepth(ii) * 1000.)
        zz = ai2 * Theta(gra,thgra,wtmp) * algcon
        hsolp(ii) = 0.
        hsolp(ii) = solpcon + (xx + yy - zz) * thour
        if (hsolp(ii) < 0.) hsolp(ii) = 0.
!! end phosphorus calculations

      else
        !! all water quality variables set to zero when no flow
        algin = 0.0
        chlin = 0.0
        orgnin = 0.0
        ammoin = 0.0
        nitritin = 0.0
        nitratin = 0.0
        orgpin = 0.0
        dispin = 0.0
        cbodin = 0.0
        disoxin = 0.0
        halgae(ii) = 0.0
        hchla(ii) = 0.0
        horgn(ii) = 0.0
        hnh4(ii) = 0.0
        hno2(ii) = 0.0
        hno3(ii) = 0.0
        horgp(ii) = 0.0
        hsolp(ii) = 0.0
        hbod(ii) = 0.0
        hdisox(ii) = 0.0
        soxy = 0.0
      endif
      end do
!! end hourly loop

!! set end of day concentrations
      algae(jrch) = halgae(24)
      chlora(jrch) = hchla(24)
      organicn(jrch) = horgn(24)
      ammonian(jrch) = hnh4(24)
      nitriten(jrch) = hno2(24)
      nitraten(jrch) = hno3(24)
      organicp(jrch) = horgp(24)
      disolvp(jrch) = hsolp(24)
      rch_cbod(jrch) = hbod(24)
      rch_dox(jrch) = hdisox(24)

      return
      end