TRANSURANIC AND TRACER SIMULANT RESUSPENSION 279 



10 



-7 



I- 

 < 



z 

 g 



to 



in 



Z) 



to 



UJ 

 CC 



10" 



I I I I I 



Respirable 



I I I I I I I I I I 



Wind-speed increment, 

 m/sec 



X O All 



A 1.3 to 20.1 



D 4.5 to 9.4 



Lower limit from 

 total time in field 



1— X 1 



Nonrespirable 



I X ' 



17 I I I I L_L 



J I I L 



I I 



_L_L 



J 



1972 



J 

 1974 



J 



DATE 



J 

 1975 



J 

 1976 



Fig. 28 "Average" wind-caused tracer resuspension rates (lightly vegetated desert on 

 Hanford reservation). 



resuspended per second. The practical significance of these numbers can be made 

 apparent by noting that a year is 3.2 x 10^ sec. 



This initial resuspension-rate correlation shows that resuspension rates decrease as 

 surface roughness increases, at least for the three smaller roughness heights. However, 

 measured resuspension rates for DDT sprayed on a forest are two orders of magnitude 

 greater than rates for the desert soil. 



This is an unexpected and unexplained increase in resuspension rates. A possible 

 explanation of the increase might be increased resuspension caused by tree movement in 

 the wind. Also, various other gross differences in controlling variables and experimental 

 factors may have influenced results. Since the data are so extremely limited, this apparent 

 correlation should be used with extreme caution until correlations based upon several 

 physical parameters instead of only Zq are developed. Nevertheless, this initial correlation 

 does give some justification for estimating resuspension rates until better correlations are 

 developed. 



