Module: ADCalculator

Defined in:
lib/ad_calculator.rb

Instance Method Summary collapse

Instance Method Details

#ad_max_inches(mad_frac, taw) ⇒ Object

Created

18May11

Author

P Kaarakka

This should be recalculated and saved whenever soils, crop, or root zone depth are changed AD is Allowable Depletion (aka RAW - Readily Available Water) madFrac is fractional form of Maximum Allowable Depletion taw is Total Available Water Result is in inches of water



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# File 'lib/ad_calculator.rb', line 30

def ad_max_inches(mad_frac, taw)
  mad_frac * taw
end

#change_in_daily_storage(daily_rain, daily_irrig, adj_et) ⇒ Object

Created

18May11

Author

P Kaarakka

daily_Rain is accumulated rainfall for the day in inches daily_Irrigation is accumulated irigation for the day in inches adj_ET is calculated in module EtCalculator Result is in inches of water



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# File 'lib/ad_calculator.rb', line 52

def change_in_daily_storage(daily_rain, daily_irrig, adj_et)
  # If any of these are nil, use 0.0 for the calculation instead of blowing up
  daily_rain ||= 0.0; daily_irrig ||= 0.0; adj_et ||= 0.0
  (daily_rain + daily_irrig) - adj_et
end

#daily_ad(prev_daily_ad, delta_stor, mad_frac, taw) ⇒ Object

Created

18May11

Author

P Kaarakka

AD is Allowable Depletion (aka RAW - Readily Available Water) prev_Daily_AD is previous day’s daily AD delta_Stor is calculated in Change_In_Daily_Storage Result is in inches of water, the smaller of max_ad_inches and the sum of previous + delta



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# File 'lib/ad_calculator.rb', line 65

def daily_ad(prev_daily_ad, delta_stor, mad_frac, taw)
  max_ad_inches = ad_max_inches(mad_frac,taw)
  [max_ad_inches,prev_daily_ad + delta_stor].min
end

#daily_ad_and_dd(prev_daily_ad, delta_stor, mad_frac, taw) ⇒ Object

Created

05Dec12

Author

R Wayne

AD is Allowable Depletion (aka RAW - Readily Available Water) prev_Daily_AD is previous day’s daily AD delta_Stor is calculated in Change_In_Daily_Storage Results are in inches of water: [AD,DD]

AD is the smaller of max_ad_inches and the sum of previous + delta
Deep Drainage is what's left over above max_ad_inches



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# File 'lib/ad_calculator.rb', line 80

def daily_ad_and_dd(prev_daily_ad, delta_stor, mad_frac, taw)
  max_ad_inches = ad_max_inches(mad_frac,taw)
  water_inches = prev_daily_ad + delta_stor
  # For some reason we're getting a rounding error here, where the water is coming up
  # infinitesmially greater than max_ad_inches. So only look for significant DD.
  drainage = water_inches - max_ad_inches
  if drainage > 0.00001
    # Return maximum possible AD -- the rest drains out
    [max_ad_inches,drainage]
  else
    # Return actual AD and no drainage
    [water_inches,0.0]
  end
end

#daily_ad_from_moisture(mad_frac, taw, mrzd, pct_mad_min, obs_pct_moisture) ⇒ Object

Created

15Jun11

Author

P Kaarakka & Rick Wayne

mad_frac and taw are used to calculate Max AD in inches mrzd, pct_mad_min and obs_pct_moisture are used to calculate the new AD Result is Allowable Depletion in inches of water (aka RAW - Readily Available Water)



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# File 'lib/ad_calculator.rb', line 101

def daily_ad_from_moisture(mad_frac,taw,mrzd,pct_mad_min,obs_pct_moisture)
  max_ad_inches = ad_max_inches(mad_frac,taw)
  [max_ad_inches,mrzd * ((obs_pct_moisture - pct_mad_min) / 100)].min
end

#daily_deep_drainage_volume(ad_max, prev_daily_ad, delta_stor) ⇒ Object

Created

18May11

Author

P Kaarakka

ad_Max is calculated in AD_Max_inches prev_Daily_AD is previous day’s daily AD delta_Stor is calculated in Change_In_Daily_Storage Result is in inches/day



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# File 'lib/ad_calculator.rb', line 128

def daily_deep_drainage_volume(ad_max, prev_daily_ad, delta_stor)
  temp_ddv = prev_daily_ad + delta_stor
  if temp_ddv > ad_max
    ddv = temp_ddv - ad_max
  else
    ddv = 0
  end
end

#pct_moisture_at_ad_min(fc, ad_max, mrzd) ⇒ Object

Created

18May11

Author

P Kaarakka

This should be recalculated and saved whenever soils, crop, or root zone depth are changed fc is field capacity mrzd is managed root zone depth adMax is calculated in AD_Max_inches Result is in percent



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# File 'lib/ad_calculator.rb', line 42

def pct_moisture_at_ad_min(fc, ad_max, mrzd)
  (fc - (ad_max/mrzd)) * 100
end

#pct_moisture_from_ad(pwp, fc, ad_max, ad, mrzd, pct_moisture_obs = nil) ⇒ Object

Created

18May11

Author

P Kaarakka

pwp is permanent wilting point mrzd is managed root zone depth pct_Moisture_At_AD_Min is calculated in Pct_Moisture_At_AD_Min ad is current day’s AD pct_Moisture_Obs is observed soil moisture for the day if pct_moisture_obs is supplied, just return that Result is in percent



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# File 'lib/ad_calculator.rb', line 116

def pct_moisture_from_ad(pwp, fc, ad_max, ad, mrzd, pct_moisture_obs=nil)
  pct_moisture_at_ad_min = pct_moisture_at_ad_min(fc, ad_max, mrzd)
  pct_moisture_obs || ([(pct_moisture_at_ad_min+((ad/mrzd)*100)),pwp].max)
end

#taw(fc, pwp, mrzd) ⇒ Object

Created

18May11

Author

P Kaarakka

This should be recalculated and saved whenever soils, crop, or root zone depth are changed TAW is Total Available Water fc is field capacity pwp is permanent wilting point mrzd is managed root zone depth Result is inches of water



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# File 'lib/ad_calculator.rb', line 18

def taw(fc, pwp, mrzd)
  (fc - pwp)*mrzd
end