Introduction 



Program Development 



The FORTRAN computer program was developed to streamline 

 hydrologic data manipulation for hydrologic zone boundary 

 determinations . 



Overview of Program Capabilities 



The program defines the lower limits of four hydrologic zone 

 boundaries, enabling determination of five zones. Recognizing the 

 inherent variability of some input parameters, the program allows input 

 of a range of parameters values, thus yielding a range of boundary 

 values. The program reads either standard formatted U.S. Geological 

 Survey (USGS) flow rate or Corps of Engineers stage data. 



Basis for Hydrologic Zone Delineation 



Definitions 



Hydrologic zones . The program assumes the following definitions 

 for hydrologic zone boundaries: 



Zone Definition 



2 Soil inundated or saturated on average greater than 

 75 percent of the growing season. 



3 Soil inundated or saturated on average between 75 and 

 25 percent of the growing season. 



4 Soil inundated or saturated on average between 25 and 

 12.5 percent of the growing season. 



5 Soil inundated or saturated on average between 

 12.5 and 5 percent of the growing season. 



6 Soil inundated or saturated on average less than 

 5 percent of the growing season. 



Inundation . Inundation is defined as the physical overtopping of 

 the soil by the adjacent stream water surface. 



Saturation . A soil is saturated when it will no longer absorb 

 water without losing an equal amount. 



Growing season . The growing season is defined as the average 

 frostfree period. It is the period between the last average occurrence 

 of 32° F in the spring and the first average occurrence of 32° F in the 

 fall. 



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