FIGURES 



Number Page 



1 The tri -river drainage area 1 



2 Location of the tri-river drainage system in the southeastern 



United States 2 



3 Important features of the Apalachicola Bay system, the major 



contributing drainages, and the barrier island complex 3 



4 Impoundments along the tri-river system 4 



5 The Apalachicola estuary 6 



6 Geological features of the Apalachicola drainage system 7 



7 Natural areas of the Apalachicola basin 9 



8 Aerial view of St. Vincent Island 11 



9 Seasonal averages of Apalachicola River flow and rainfall from 



Columbus, GA, and Apalachicola, FL 11 



10 Six-month and thirty-six month moving averages of Apalachicola River 



flow and Apalachicola rainfall 12 



11 Net water current patterns in the Apalachicola estuary as indicated 



by flow model s 14 



12 Apalachicola River flow and monthly average minimum air temperature 15 



13 SYNMAP projections of average levels of salinity, dissolved oxygen, 

 turbidity, and color at permanent stations in the Apalachicola 



estuary 16 



14 Surface salinity at stations 1 and 5 in the Apalachicola estuary from 



1972 through 1982 17 



15 Surface dissolved oxygen at stations 1 and 5 in the Apalachicola 



estuary from 1972 through 1982 18 



16 Water color at stations 1 and 5 in the Apalachicola estuary from 



1972 through 1982 19 



17 Turbidity at stations 1 and 5 in the Apalachicola estuary from 



1972 through 1982 19 



18 Frequently flooded areas and soil associations in the Apalachicola 



River Basin 23 



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