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POPULAR SCIENCE MONTHLY 



THE PROTECTION OF THE ALLUVIAL BASIN" OF THE 



MISSISSIPPI 1 



By ROBERT MARSHALL BROWN 

 WORCESTER STATE NORMAL SCHOOL 



^r^HE hydrographic or drainage basin of the Mississippi River 

 -*- (Fig. 1) is equivalent in area to one third of the United States. 

 Thirty-two states and territories contribute water to the volume of the 

 river; eight of these divisions send water to no other system. The dis- 

 charge of rivers is not in any proportionate way related to the size of 

 their drainage basins. The potent factors which determine the volume 

 of discharge are the precipitation of rain over the basin and the char- 

 acter of the soil. The upper Ganges has a basin less than one seventh 

 that of the Mississippi. It equals the latter river, however, in the 

 volume of its discharge. The Hoang Ho, with a basin area fifty per 

 cent, only of that of the Mississippi, discharges more than twice as 

 much water into the sea. If the discharge of the Mississippi propor- 

 tionally to the size of its basin equaled that of the Po, the volume of 

 the discharge of the former would be multiplied by six. The Danube 

 more nearly equals the Mississippi in the ratio of discharge to size of 



Fm. L. Hydrographic Basin of the Mississippi, with Rainfall Types. Missouri type 

 has the maximum rainfall in April, May and June ; Tennessee, in February and March ; Lake, 

 a late spring maximum in June, and an early fall maximum in September. 



1 Compiled, largely, from the reports of the Mississippi River Commission. 



