amplitude of 0.10 foot and a discharge into Pentwater Lake of 

 2,800 cubic feet per second from the Pentwater River. The model 

 predicted an average bay water surface elevation of 0.13 foot 

 higher than the mean lake level, a bay water level fluctuation 

 range of 0.25 foot, and a prism of water of 4.6 x 10^ cubic feet 

 caused by the seiche (Fig. 8). The inlet would always be in ebb 

 flow due to river influence with a maximum velocity of -2.7 feet 

 per second and a minimum velocity of -0.1 foot per second. Head, 

 friction, and temporal and convective acceleration are important 

 in the inlet equation of motion. 



IV. SUMMARY 



A computer program (INLET) based on a numerical model (Seelig, Harris, 

 and Herchenroder, in preparation, 1977)^ is presented for prediction of 

 hydraulics v/here one or more inlets connect a bay to a sea. Two examples 

 are given: (a) A tidal inlet forced by an astronomical tide where inlet 

 channel friction is the dominant term in the equation of motion; and (b) 

 a Great Lakes inlet with river inflow forced by lake seiching where head, 

 friction, and temporal and convective accelerations are important at 

 different points in the water level fluctuation cycle. The model can 

 also be used for forcing other water level fluctuations, such as from 

 storm surges or tsunamis. 



Another computer program (INLET2) is available for more complex 

 systems of interconnected inlets, bays, and seas. INLET2 is an expanded 

 version of INLET. Documentation and computer card decks for INLET2 are 

 available from the Automatic Data Processing Division (CERDP) , Coastal 

 Engineering Research Center (CERC) . 



Details on model development and application, including additional 

 examples, are reported by Seelig, Harris, and Herchenroder (in prepara- 

 tion, 1977)1. 



^SEELIG, HARRIS, and HERCHENRODER, op. cit., p. 7. 



