code: def calc_et0_v1(self):
      
      con = self.parameters.control.fastaccess
      inp = self.sequences.inputs.fastaccess
      flu = self.sequences.fluxes.fastaccess
      for k in range(con.nhru):
          flu.et0[k] = (con.ke[k]*(((8.64*inp.glob+93.*con.kf[k]) *
                                    (flu.tkor[k]+22.)) /
                                   (165.*(flu.tkor[k]+123.) *
                                    (1.+0.00019*min(con.hnn[k], 600.)))))
docs: Calculate reference evapotranspiration after Turc-Wendling.
  
      Required control parameters:
        |NHRU|
        |KE|
        |KF|
        |HNN|
  
      Required input sequence:
        |Glob|
  
      Required flux sequence:
        |TKor|
  
      Calculated flux sequence:
        |ET0|
  
      Basic equation:
        :math:`ET0 = KE \\cdot
        \\frac{(8.64 \\cdot Glob+93 \\cdot KF) \\cdot (TKor+22)}
        {165 \\cdot (TKor+123) \\cdot (1 + 0.00019 \\cdot min(HNN, 600))}`
  
      Example:
  
          >>> from hydpy.models.lland import *
          >>> parameterstep('1d')
          >>> simulationstep('12h')
          >>> nhru(3)
          >>> ke(1.1)
          >>> kf(0.6)
          >>> hnn(200.0, 600.0, 1000.0)
          >>> inputs.glob = 200.0
          >>> fluxes.tkor = 15.0
          >>> model.calc_et0_v1()
          >>> fluxes.et0
          et0(3.07171, 2.86215, 2.86215)