DRAINAGE AND CLIMATE 209 



rainfall are : (1) the apparently insufficient moisture 

 supply during most growing seasons ; and (2) the falling 

 ground water-table and drying up of springs, discussed 

 in a previous chapter. 



Unquestionably, the insufficient water supply for grow- 

 ing crops must be charged, very largely, to carelessness 

 and the unintelligent methods employed in soil and crop 

 management. The falling of the ground water-table 

 and the failing of springs are not necessarily due to 

 diminishing rainfall, as was shown in previous chapter. 



279. Floods and their relation to rainfall. The occur- 

 rence of floods is sometimes offered as a proof of an in- 

 creasing rainfall. Summer floods, and sometimes winter 

 floods, are the results of erratic or unusual rainfall, ex- 

 cessive or long continued or both. The Paris flood of 

 January, 1910, was due to heavy rainfall which had been 

 preceded by rains sufficiently heavy and long continued 

 completely to saturate the soil. 1 The magnitude of this 

 flood was such that the Seine River carried thirty times 

 its normal volume of water at twenty times its usual speed. 

 At the time of the Dayton flood in March, 1913, a rainfall 

 of 5 inches occurred in one 24-hour period over the Miami 

 basin, and a total of 8.8 inches in one week. 2 On June 

 17, 1915, at one point in the middle Missouri Valley flood 

 district, 5.78 inches of rain fell in nine hours. 3 For the 

 month of June the rainfall at Columbia, Missouri, was 9.11 

 inches ; at Topeka, Kansas, 9.10 inches ; at lola, Kansas, 

 8.56 inches and at Kansas City, 7.88 inches. These erratic 

 rainfalls, however, cannot be accepted as evidence that the 

 mean rainfall of any region is increasing. Erratic rain- 



1 Scientific American, Vol. Oil, No. 8, p. 164. 



2 A. J. Henry, Weather Bureau, Bui. Z, 1913. 



3 P. Conner, M.W.R., Vol. XLIII, No. 6, p. 28. 



