pothole.f

水文模型的原始代码

      subroutine pothole
      
!!    ~ ~ ~ PURPOSE ~ ~ ~
!!    this subroutine simulates depressional areas that do not drain to the 
!!    stream network (potholes) and impounded areas such as rice paddies

!!    ~ ~ ~ INCOMING VARIABLES ~ ~ ~
!!    name           |units         |definition
!!    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
!!    curyr          |none          |current year of simulation
!!    evlai          |none          |leaf area index at which no evaporation
!!                                  |occurs from the water surface. This
!!                                  |variable is used in ponded HRUs (eg rice)
!!                                  |where evaporation from the water surface
!!                                  |is restricted by the plant canopy cover.
!!                                  |Evaporation from the water surface equals
!!                                  |potential ET when LAI = 0 an decreases
!!                                  |linearly to O when LAI = EVLAI
!!    hru_dafr(:)    |none          |fraction of watershed area in HRU
!!    hru_ha(:)      |ha            |area of HRU in hectares
!!    hru_slp(:)     |m/m           |average slope steepness
!!    iida           |julian date   |day being simulated (current julian date)
!!    ihru           |none          |HRU number
!!    ipot(:)        |none          |number of HRU (in subbasin) that is ponding
!!                                  |water--the HRU that the surface runoff from
!!                                  |current HRU drains into. This variable is
!!                                  |used only for rice paddys or closed
!!                                  |depressional areas
!!    imp_trig(:,:,:)|none          |release/impound action code:
!!                                  |0 begin impounding water
!!                                  |1 release impounded water
!!    irelease(:,:,:)|julian date   |date of impound/release operation
!!    laiday(:)      |none          |leaf area index
!!    nrelease(:)    |none          |sequence number of impound/release
!!                                  |operation within the year
!!    nro(:)         |none          |sequence number of year in rotation
!!    nyskip         |none          |number of years to skip output 
!!                                  |summarization/printing
!!    pet_day        |mm H2O        |potential evapotranspiration on current day
!!                                  |in HRU
!!    pot_fr(:)      |km2/km2       |fraction of HRU area that drains into 
!!                                  |pothole
!!    pot_no3(:)     |kg N          |amount of nitrate in pothole water body
!!    pot_no3l(:)    |1/day         |nitrate decay rate in impounded area
!!    pot_nsed(:)    |mg/L          |normal sediment concentration in impounded
!!                                  |water (needed only if current HRU is IPOT)
!!    pot_sed(:)     |metric tons   |amount of sediment in pothole water body
!!    pot_tile(:)    |m3/d          |average daily outflow to main channel from
!!                                  |tile flow if drainage tiles are installed
!!                                  |in pothole (needed only if current HRU is 
!!                                  |IPOT)
!!    pot_vol(:)     |m**3 H2O      |current volume of water stored in the
!!                                  |depression/impounded area
!!    pot_volx(:)    |m**3 H2O      |maximum volume of water stored in the
!!                                  |depression/impounded area
!!    qday           |mm H2O        |surface runoff loading to main channel from
!!                                  |HRU for day
!!    sed_stl(:)     |kg/kg         |fraction of sediment remaining suspended in
!!                                  |impoundment after settling for one day
!!    sedyld(:)      |metric tons   |daily soil loss caused by water erosion 
!!                                  |in HRU
!!    sol_k(:,:)     |mm/hr         |saturated hydraulic conductivity of soil
!!                                  |layer
!!    sol_nly(:)     |none          |number of layers in soil profile
!!    sol_por(:,:)   |none          |total porosity of soil layer expressed as
!!                                  |a fraction of the total volume
!!    sol_st(:,:)    |mm H2O        |amount of water stored in the soil layer
!!                                  |on any given day
!!    sol_sumfc(:)   |mm H2O        |amount of water held in the soil profile
!!                                  |at field capacity
!!    sol_sw(:)      |mm H2O        |amount of water stored in soil profile on
!!                                  |current day
!!    sol_z(:,:)     |mm            |depth to bottom of soil layer
!!    spadyev        |mm H2O        |average annual amount of water removed
!!                                  |from potholes by evaporation in watershed
!!    spadyo         |mm H2O        |average annual amount of water released to 
!!                                  |main channel from potholes in watershed
!!    spadyrfv       |mm H2O        |average annual amount of precipitation on
!!                                  |potholes in watershed
!!    spadysp        |mm H2O        |average annual amount of water removed
!!                                  |from potholes by seepage in watershed
!!    subp(:)        |mm H2O        |precipitation for the day in HRU
!!    surqno3(:)     |kg N/ha       |amount of NO3-N in surface runoff in HRU
!!                                  |for the day
!!    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

!!    ~ ~ ~ OUTGOING VARIABLES ~ ~ ~
!!    name           |units         |definition
!!    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
!!    pot_no3(:)     |kg N          |amount of nitrate in pothole water body
!!    pot_sed(:)     |metric tons   |amount of sediment in pothole water body
!!    pot_vol(:)     |m**3 H2O      |current volume of water stored in the
!!                                  |depression/impounded area
!!    potevmm        |mm H2O        |volume of water evaporated from pothole
!!                                  |expressed as depth over HRU
!!    potflwi(:)     |m^3 H2O       |water entering pothole on day
!!    potflwo        |mm H2O        |discharge from pothole expressed as depth
!!                                  |over HRU
!!    potpcpmm       |mm H2O        |precipitation falling on pothole water body
!!                                  |expressed as depth over HRU
!!    potsa(:)       |ha            |surface area of impounded water body
!!    potsedi(:)     |metric tons   |sediment entering pothole on day
!!    potsedo        |metric tons   |sediment leaving pothole on day
!!    potsepmm       |mm H2O        |seepage from pothole expressed as depth over
!!                                  |HRU
!!    qday           |mm H2O        |surface runoff loading to main channel from
!!                                  |HRU for day
!!    sedyld(:)      |metric tons   |daily soil loss caused by water erosion 
!!                                  |in HRU
!!    sol_st(:,:)    |mm H2O        |amount of water stored in the soil layer
!!                                  |on any given day
!!    sol_sw(:)      |mm H2O        |amount of water stored in soil profile on
!!                                  |current day
!!    spadyev        |mm H2O        |average annual amount of water removed 
!!                                  |from potholes by evaporation in watershed
!!    spadyo         |mm H2O        |average annual amount of water released to 
!!                                  |main channel from potholes in watershed
!!    spadyrfv       |mm H2O        |average annual amount of precipitation on
!!                                  |potholes in watershed
!!    spadysp        |mm H2O        |average annual amount of water removed
!!                                  |from potholes by seepage in watershed
!!    surqno3(:)     |kg N/ha       |amount of NO3-N in surface runoff in HRU
!!                                  |for the day
!!    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

!!    ~ ~ ~ LOCAL DEFINITIONS ~ ~ ~
!!    name        |units         |definition
!!    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
!!    cnv         |none          |conversion factor (mm/ha => m^3)
!!    dg          |mm            |depth of soil layer
!!    excess      |mm H2O        |amount of water moving into soil that exceeds
!!                               |storage of layer
!!    j           |none          |HRU number
!!    ly          |none          |counter (soil layers)
!!    no3loss     |kg N          |amount of nitrate lost from water body
!!    pi          |none          |pi
!!    potev       |m^3 H2O       |evaporation from impouned water body
!!    potmm       |mm H2O        |volume of water in pothole expressed as depth
!!                               |over HRU
!!    potpcp      |m^3 H2O       |precipitation falling on water body
!!    potsep      |m^3 H2O       |seepage from impounded water body
!!    sedloss     |metric tons   |amount of sediment lost from water body
!!    sedsetl     |metric tons   |amount of sediment settling out of water
!!                               |during day
!!    spillo      |m^3 H2O       |amount of water released to main channel from
!!                               |impounded water body due to spill-over
!!    stmax       |mm H2O        |maximum water storage in soil layer
!!    sumo        |m^3 H2O       |sum of all releases from water body on
!!                               |current day
!!    tileo       |m^3 H2O       |amount of water released to the main channel
!!                               |from the water body by drainage tiles
!!    yy          |none          |fraction of maximum seepage allowed to occur
!!    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

!!    ~ ~ ~ SUBROUTINES/FUNCTIONS CALLED ~ ~ ~
!!    Intrinsic: Abs, Min, Max

!!    ~ ~ ~ ~ ~ ~ END SPECIFICATIONS ~ ~ ~ ~ ~ ~

      use parm

      real, parameter :: pi = 3.1416
      integer :: j, ly
      real :: potsep, sumo, potev, cnv, potpcp, spillo
      real :: sedloss, no3loss, yy, dg, excess, stmax, sedsetl
      real :: potmm

      j = 0
      j = ihru

!! initialize variables
      potev = 0.
      potpcp = 0.
      potsep = 0.