c     file: cenvr.inc

c     This file contains the declaration of the common block of variables
c     related to the weather data and temperature factors.

c     + + + VARIABLE DECLARATIONS + + +
C      real tmx,tmn,r,ra,rh,tav,vpd,tava,hrlt,hrlty,hlmn0,
       real vpd,tava,hrlt,hrlty,hlmn0,
     & shu,dhu,hui,dhuf,huf,hufy,ehu,tplant,frst,fhr,
     & ts,hu,xlat,cta,ceta,ctab,cetab,ctas,cetas,ctay,cetay,prcp,
     & prcpb,prcpy,prcps,ctp,ctpb,ctpy,ctps, frs1, frs2,phu
      integer jda,jd

C      common / envr /tmx,tmn,r,ra,rh,tav,vpd,tava,hrlt,hrlty,
       common / envr / vpd,tava,hrlt,hrlty,
     & hlmn0,shu,dhu,hui,dhuf,huf,hufy,jda,jd,ehu,frs1,frs2,
     & tplant,frst,fhr,ts,hu,xlat,cta,ceta,ctab,cetab,ctas,cetas,
     & ctay,cetay,prcp,prcpb,prcpy,prcps,ctp,ctpb,ctpy,ctps,phu

c     + + + VARIABLE DEFINITIONS + + +
c    cta - actual cummulated transpiration (mm)
c    ctab - periodic actual cummulated transpiration (mm) on day i
c    ctay - periodic actual cummulated transpiration (mm) on day i-1
c    ctas - seasonal actual cummulated transpiration  (mm)
c    ctp - potential cummulated transpiration (mm)
c    ctpb - periodic potential cummulated transpiration (mm)on day i
c    ctay - periodic potential cummulated transpiration (mm)on day i-1
c    ctas - seasonal potential cummulated transpiration  (mm)
c    ceta - actual cummulated evapotranspiration (mm)
c    cetab - periodic actual cummulated evapotranspiration (mm)on day i
c    cetay - periodic actual cummulated evapotranspiration (mm)on day i-1
c    cetas - seasonal actual cummulated evapotranspiration (mm)
c    dhu - daily heat units (deg. c)
c    dhuf - daily heat unit factor
c    ehu - heat units required from planting seedling emergence
c    frs1 - lower temperature threshold for frost damage (deg. C)
c    frs2 - upper temperature threshold for frost damage (deg. C)
c    frst - frost damage factor
c    fhr - reduction due to day length factor
c    hrlt - day length on day i (h)
c    hrlty - day length on day (i-1)
c    hlmn0 - minimum length of day for a location plus 1 hour
c    hui - heat unit index (ratio of shu to phu)
c    hui0 - heat unit index when leaf senescence starts.
c    huf - heat unit factor for driving leaf-area-index development
c    hufy - value of huf on day (i-1)
c    jda - date of sowing (same as day simulation begins)
c    jd - today's julian date calander
c    phu - potential heat units for crop maturity (deg. c)
c    prcp - cummulated precipitation (mm)
c    prcpb - periodic cummulated precipitation (mm)
c    prcpy - previous value of prcpb (mm)
c    prcps - season cummulated precipitation (mm)
c    r - daily precipitation (mm/day)
c    ra - solar radiation (mj/day)
c    rh - relative humidity (ratio)
c    shu - cummulated heat units ( deg. c)
c    tmn - manimum air temperature (deg. c)
c    tbas - base temperature (deg. c)
c    tmx - maximum air temperature (deg. c)
c    topt - optimum temperature (deg. c)
c    tplant - minimum soil temperature for planting (c)
c    ts - temperature stress factor
c    vpd - vapor pressure deficit (kpa)
c    xlat - latitude of a location (deg.)