1. Make your equation sheet for the test and turn it in.
2. Solve for evapotranspiration (mm/m) for April, May, June and July using the Blaney Criddle Methods, Priestley Talyor
Method and Penman Monteith Method (ALL 3). Fill in the below table with all values. By hand write out the steps for
each method using data from May. Finally, create a graph comparing the monthly ET values of all three methods.
3. Calculate the difference between ET and P for each month using each method and then graph your results. If you were a
farmer, how might the different ways of estimating ET change your irrigation schedule?
Located at Latitude of 48° N
Month
Mean
Temp
(°C)
Mean
RH (%)
Mean
Wind
Speed
(m/s)
Mean
Monthly
Sunshine
(h)
p (%)
daily
light
Mean
Maximu
m Month
(hr)
Total
Precip
(mm)
Alph
a
RN
(MJ/
m2)
G
(MJ/
m2)
Cp
Specifc
Heat
Capacity
(KJ/kg
°C)
Rc
(s/m)
Ra
(s/m)
April 11.8 53.9 7.1 6.9 0.31 7.44 138 1.26 278.6 5 1.006 70 100
May 18.4 36.5
