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NEW YORK STATE MUSEUM 



given for evaporation on the Sudbury, Croton and Passaic rivers. 

 The following is his general formula for all streams : 



E =(15.50 + 0.16 R) (0.05 T — 1.48) (19) 

 This, however, he states is merely a suggestion. His purpose 

 is to deduce laws which hold for the State of New Jersey alone. 



In these formulas the evaporation is taken to include all the 

 various losses of water to which a catchment area is subject, 

 including direct evaporation as well as water absorbed and 

 transpired by plant growth, etc. Hence, 



F ( runoff )=R — E. (20 > 



Mr Vermeule gives the following formulas for the Sudbury,. 

 Croton and Passaic rivers : 



December-May, E=4.20+0.12 R; (21) 

 June-November, E=11.30+0.20 R. (22) 

 These formulas take into account the fact that evaporation is 

 low in the winter months and high during the summer. 



Mr Vermeule also gives the following formula for computing 

 monthly evaporation from the monthly rainfall for Sudbury, 

 Croton and Passaic catchment areas: 



[e = monthly evaporation; r = monthly rainfall.] 



December e= 0.42+0.10 r J 



January e= 0.27+0.10 r | 



February e= 0.30+0.10 r ' 



March e= 0.48+0.10 r j 



April e= 0.87+0.10 r 



May e= 1.87+0.20 r j 



June e= 2.50+0.25 r ! 



July e= 3.00+0.30 r j 



August e= 2.62+0.25 r j 



September e= 1.63+0.20 r j 



October e= 0.88 +0.12 r j 



November e= 0.66+0.10 r | 



Year e=l 5.50+0.16 r j 



To obtain the monthly evaporation for other streams the 

 results obtained are multiplied by the following: 



(0.05 T— 1.48) 

 In which T ---mean annual temperature. 



