12 3 4 5 6 7 



U Ti* U V U f U 





1 

 1 

 1 

 1 



Hi 











E 



1 

 D 



C 



r 



B 



1 



A 



















Fig. 4. Schematic of one dimensional channel with stair-step depth 

 profile. Capital letters A through E indicate locations where the 

 gradients \.^(^i/T^'> ] a^e defined. 



29 



