Table 4. Numbers of observations, mean widening rate from 1957 to 1978, and 

 standard error for different canal types in the Leeville oil field (A) and 

 analysis of variance indicating differences in canal widening rates for the 

 period from 1957 to 1978 (B) (See Table 1 for canal types). 



A. 



Canal 

 type 



Number of 

 observations 



Mean 

 (m/yr) 



Standard 

 error 



NMC 

 OFNC 

 SMNC 

 SNMC 



13 

 20 

 34 

 25 

 12 



2.58 

 0.95 

 1.12 

 1.20 

 1.16 



0. 

 0. 

 0. 

 0. 



0. 



85 

 13 

 11 

 15 

 15 



Source 



df 



SS 



MS 



Canal type 

 MNW vs. OFNC 

 MNW vs. NMC 

 SMNC vs. SNMC 



Error 



Total 



a **Highly significant (p < 0.01) 

 b NS Not significant (p > 0.05) 



68 



