Lake Evaporation Calculation Cancel The title field is required!

1. Flanagan Darren C

   
   6/7/2013 4:06 PM

   G´Day All
   
   Anyone have a basic lake evaporation rate calculation? I am starting some new tracking data and was wondering if anybody had this. I have lake surface areas,depths and we are tracking daily et data.
   
   Thank you in advance!
   
   Darren Flanagan
   El Dorado Beach Club, Mexico

   
   
   
   
2. Keith Pegg

   

   0 posts
   
   6/7/2013 7:06 PM

   I have lakes some that are plastic lined and the pan evaporation rate ET from my irrigation computer is very close. then just do the math for gals per lake in the summer here it runs .07 to .17 per day and I have to add a little water every few days if it is hot for a week or so without rain. rain keeps these lake full 90% of the time.
   
   Keith Pegg
   Zama Japan

   
   
   
   
3. Flanagan Darren C

   
   6/8/2013 7:06 AM

   Keith
   
   Thanks for your reply, are you using metric or imperial in Japan? just curious
   
   I use both here as the products are in metric but the staff are used to imperial.
   
   Darren

   
   
   
   
4. Keith Pegg

   

   0 posts
   
   6/8/2013 6:06 PM

   Darren Flanagan"]Keith
   
   Thanks for your reply, are you using metric or imperial in Japan? just curious
   
   I use both here as the products are in metric but the staff are used to imperial.
   
   
   I use Imperial but in Japan they use metric, Because we are US Army we use Imperial, myself I would use metric for everything if I could it is so much better.
   On your lakes an acre ft of water 12" = 32,373 gal a tenth of an inch is 3,237 gal and so on.
   My Mechnics do use metric for mower setup so like greens 3.5mm or a little lower than 9/64th or .140"

   
   
   
   
5. Michael Rogers

   

   2 posts
   
   6/9/2013 2:06 AM

   Hi Darren, Here are a couple of links. The first has a specific section about open water. These calculations will wreck your head. The RainBird and Toro systems use slightly different methods to calculate the ET but very similar to the gibberish in the first link. The terminology for ET is about as clever as redox potential, NOT
   
   The first is a lot of FAO info and I saw Dave Kopec quoted on the very bottom. The second is from Univ of Arizona. If it is not in this clip it is in another similar bulletin. The Univ of Arizona say to use .7 crop factor for large bodies of water.
   
   The metric system is so easy for water and soil calculations. I use all metric but can convert very easily to Americano if necessary.
   
   Pounds per acre foot is just so silly, PLEASE mg per liter equals ppm one liter weighs 1 kilo one cubic meter weighs one tonne ( 1000 kilos or 2205 pounds ) that is EASY PEASEY
   
   http://content.alterra.wur.nl/Internet/ ... b46-h4.pdf
   
   http://ag.arizona.edu/pubs/water/az1324.pdf
   
   Michael Rogers
   Down to EARTH Water Management