10 



soil phases, texture, and permeability coefficients) were available; and 

 (5) plant communities were characteristic (e.g., plant communities with 

 few rarely occurring species) of the study area. 



Site Selection 



Several hundred potential sites were considered, but most were 

 eliminated because of insufficient stream gauge data. More than 50 

 sites were visited, but only 17 (Figure 2) satisfied all site criteria 

 and were used in the study. Although all 17 sites met the selection 

 criteria, not all hydrologic zones in each site were suitable for study. 

 Some zones were too narrow and others had been disturbed recently by 

 agricultural or silvicultural practices. 



Sites 1 and 2 were located in the Neches River basin in southeast- 

 ern Texas. The Steele Bayou, Yazoo River, and Big Black River basins in 

 Mississippi, respectively, were designated sites 3, 6, and 7. Sites 4 

 and 5 were located in the Ouachita River and sites 8 and 9 in the 

 L'Anguille River basins in Arkansas. Site 10 was located in the Pearl 

 River basin in Louisiana, and sites 11 and 12 in the Apalachicola River 

 basin in Florida. Sites 13 and 14 were located in Georgia in the 

 Ocmulgee River and Altamaha River basins, respectively. Sites 15, 16, 

 and 17 were located in South Carolina in the Edisto, Lynches, and 

 Waccamaw River basins, respectively. 



All sites were characterized by a growing season of greater than 

 200 days and average annual rainfall ranging from 105 to 170 cm. The 

 overstory typically ranged from cypress -tupelo or willow in depressions 

 and low flats to white oak-hickory or pine on the high ridges. Inter- 

 mediate areas included overcup oak-bitter pecan, green ash, willow oak, 



