92 



Separation of Data into Growing Seasons 



Required inputs . The program used the starting and ending dates 

 of the growing season and the daily flow rates or daily stage data at 

 each site for a period of 10 to 20 years as input. Henceforth, the 

 terms "flow rate" and "stage" are interchangeable, depending on the form 

 of input data. 



The program read flow rate data into a matrix FL(I,J), where I is 

 an index designating year, and J designated the Julian date. For exam- 

 ple, FL(3,3) designated the flow rate of January 3 of the third year of 

 data and FL(3,33) designated February 2 of the third year. Two 

 matrices, K5GS(I) and KEGS (I), were created that contained Julian dates 

 of the beginning and end of the growing season in each year I. These 

 dates varied due to leap years. 



The program then created two more matrices: FLGS(I,J) and 

 NDGS(I). FLGS(I,J) contained flow rates in year I, on date J from the 

 beginning of the growing season. For example, FLGS(2,3) designated the 

 flow rate on the third day of the growing season in the second year of 

 data. NDGS(I) is the number of days in the growing season of the I th 

 year. Again, this varied due to leap years. 



Computation of Days Inundated 



Computation of days inundated at a given flow rate proceeded as 

 follows : 



1. Growing season flow rates for the entire entered record were 

 ranked from highest to lowest. This was accomplished by 

 transferring all data in the FLGS(I.J) matrix into a single 

 subscripted matrix RANK(K) , and then ranked the data in RANK 

 using a bubble sorting routine. RANK(l) represented the 

 greatest flow rate for the entire record. RANK(NQ) was the 

 lowest flow rate, where NQ was the total number of growing 

 season flow rates in the entire record. 



2. The number of days a given flow rate was exceeded (i.e., 

 effecting inundation above that flow rate) within the growing 

 season record was equal to the flow rate's ranking. A flow 

 rate in RANK(IO) was equalled or exceeded 10 times within the 

 historic record and corresponded to 10 days of inundation. 



Computation of Days Saturated 



General . The model for the program was a simplified water bal- 

 ance. The soil root zone for wetland plant species was considered to be 

 a water bucket, where: 



1. Depth of the bucket was the critical depth of the saturated 

 zone (e.g., 25 cm) . 



2. When water overtopped the bucket (i.e., during inundation), 

 the bucket filled at a rate PKW (inches/hour). 



