INVESTIGATION OF OYSTER SPAWNING, ETC., MILFORD, CONN. 



445 



PRECIPITATION 



In rainfall or precipitation we have another important climatological factor that 

 should be considered with air temperature. The quantity of fresh water discharged 

 into the harbors depends largely upon the intensity and amount of precipitation, 

 while its temperature is determined by the temperature of the air and land in this 

 particular drainage basin. The effect of precipitation on harbor-water temperatures 

 depends, therefore, on the quantity and temperature of fresh water discharged 

 into it. When both air temperature and precipitation are above normal, as they 

 were in 1922 and 1925, their combined influence on the physical condition of the 



INCHES 



2^ 



20 

 16 

 16 



12 

 10 

 d 

 6 

 4 

 2 



NORMAL 1922 1925 1924 1925 1926 



Figure 9.— Total precipitation for the period April 1 to August 1 



1927 



water in the harbor is considerable, as there is not only an increase in water tem- 

 perature but also a decided change in the chemical composition of the water. The 

 daily precipitation, in inches, for July and August, 1925 and 1926, is presented 

 in Figure 6, together with the water temperatures. In Figure 9 the normal and 

 monthly amounts of the total precipitation for the period April 1 to August 1 is 

 shown for the six years and clearly demonstrates the variations in rainfall that have 

 occurred each spring and summer. According to Hoyt and Grover (1916), in this 

 region approximately 40 per cent of the rainfall reaches the streams as run-off during 

 these months, and its importance can hardly be overlooked in view of the fact that 

 Long Island Sound receives the drainage of virtually all of the State of Connecticut 

 and a large portion of Massachusetts, Vermont, and New Hampshire. In the 



