71 



It will be observed that tank consumptive use of 14.3 in- 

 ches for May does not differ greatly from the average swamp use 

 of 12.9 acre-inches. The larger use should be expected on ac- 

 count of the artificial conditions in the tanks. Moving tank B 

 to Ontario in June placed this tank under conditions radically 

 different from those inherent in swamp areas, and the consumptive- 

 use records for June, July, and August are neither applicable to 

 field conditions nor comparable with previous records at Temescal 

 Creek. Their value lies in the chart records obtained and the 

 opportunity presented for comparing the rate of consumptive use- 

 of -water curves with the daily temperature curves shown in Figure 

 8. The maxima and minima of these curves occur respectively about 

 the same time of day. 



The effect of consumptive use on ground-water levels is 

 apparent on the stream-flow chart. Under normal conditions the 

 draft on the water table following the peak of transpiration is 

 shown by the falling side of the curve representing daily stream 

 flow. At this time consumptive use exceeds the recharge of the 

 basin and the water table is dropping. At the bottom of the 

 curve, consumptive use and recharge are balanced and the water 

 table begins to rise. During periods of maximum consumptive use, 

 the recharge may not equal the daily loss, and under these condi- 

 tions the dropping water table is reflected in lower stream flow. 



As sunlight and temperature so greatly affect transpiration 

 and consumptive use by plants, the following discussion by Taylor 

 (2) on the effects of insolation is applicable: 



PROBABLE LIMITS TO THE LOSSES ALONG 

 STRE/Jl CHANNELS 



"The indicated loss of 12.9 inches in 30 days at Temescal 

 Creek, together with still higher rates of loss from small isolat- 

 ed tanks of swamp grovrth, has led to a consideration as to what 

 the probable limits for losses in moist areas along stream chan- 

 nels might be. The radiant energy received from the sun, or 



