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INDIANA UNIVERSITY STUDIES 



Causes of Floods in the Ohio Valley 



Floods above the danger line, in the Ohio Valley, have re- 

 sulted from the following causes, acting alone, or in conjunction: 



1. Heavy rainfall over extensive areas, 



2. Rapid melting of large accumulations of snows. 



3. The formation and the breaking of ice jams. 



4. The failure of reservoirs. 



5. The breaking of levees. 



The first two of these causes acting together are responsible 

 for a very large percentage of the floods that occur during the first 

 four months of the year. A great number of the floods occur dur- 

 ing the first four months of the year. For instance, at Paducah, 

 out of the twenty-nine floods that have been above the danger line 

 all have occurred during the first four months of the year. At 

 Evansville, out of the eighty-six floods that were above the danger *• 

 point, only ten occurred outside of these months; and at Cincinnati, 

 only three out of forty-six occurred outside of the months of January, 

 February, March and April. 



The last three of these causes generally act in conjunction 

 with the first two, and in themselves seldom do any great amount 

 of damage over any but a small area. The last flood was caused by 

 excessive precipitation over a large territory, and was not aided in 

 the least by the other flood-causing factors. 



