CONTENTS — PART I 



11 



LIST OF PLATES 



Plate Page 



Geographical locations of stations Frontispiece 



I. Plan of Santa Ana Station 27 



II. Mariotte tank connected to soil tank to maintain a constant water 

 level in the soil and supply water, evaporated or transpired, Santa 



Ana station, 1929-1932 31 



III. Board housing for Mariotte tanks at San Bernardino 33 



IV. Circular metal covers to protect soil tanks from rainfall while allow- 

 ing free circulation of air over the tank surface 4G 



V. Monthly use of water by salt grass in tanks having various depths 



to water table 52 



VI. Bermuda grass in tanks in field of similar growth at San Bernardino. 



The tanks are in the center of the picture showing heavier growth 57 



VII. Comparison of use of water by Bermuda grass at San Bernardino with 

 that of salt grass at Santa Ana and evaporation from water in 



Tank No. 16 at Santa Ana_- 58 



VIII. A. Tules growing in tank six feet in diameter at Santa Ana station, 



1931, with small tanks of tules and cat-tails at the right GO 



B. Cat-tails growing in small tank, Santa Ana station, 1931 60 



C. Tules growing in small tank, Prado station, 1931 60 



IX. Hourly rate of use of water by tules, evaporation from standard 



Weather Bureau pan and air and water temperatures, Prado 



station 61 



X. Willow tree growing in 6-foot tank, Santa Ana station, 1931 65 



XI. Moist area along the Mojave River above the Upper Narrows near 



Victorville, California 76 



XII. Plan of Victorville station 77 



XIII. Arrangement for tank No. 2 to supply water and to measure amount 



of evaporation and transpiration 7S 



XIV. Arrangement for tank No. 3 to regulate supply of water and to 



measure amount of evaporation and transpiration 78 



XV. A. General view of Victorville station, taken October 31, 1931 79 



B. View taken October 31, 1931, of swamp where two tanks were 



located, the stadia rod being held between the two tanks 7 9 



XVI. View of tank No. 1, taken October 31, 1931 80 



XVII. Monthly evaporation and use of water from tanks No. 1, No. 2 and 



No. 3, February, 19 31-February, 1932 : 81 



XVIII. Mean monthlv evaporation and use of water from tanks No. 1, 



No. 2 and No. 3 83 



XIX. Aerial view of Coldwater Canyon showing location of the controls 89 



XX. A. Alders in canyon bottom viewed from an overhanging cliff 91 



B. Alders in canyon bottom about midway between the middle and 



lower controls 91 



XXI. Middle Coldwater control showing 3-inch Parshall measuring fluVne 



and flow, recorder 93 



XXII. Combination flume for measurement of water at both high and low 



stages 95 



XXIII. Flow recorder installation at lower Coldwater control 96 



XXIV. A. Evaporimeter with shallow black pan 24 inches in diameter 98 



B. Evaporimeter showing weighing mechanism and record cylinder 9 8 



XXV. Evaporimeter charts 99 



XXVI. Fluctuation in the water table in Coldwater Canyon, September 7-15, 



1932 100 



XXVII. Flow at Middle Coldwater Canyon control, August 9-15, 1931 102 



XXVIII. A. Drop in flow in Coldwater Canyon, August 11-12, 1931 103 



B. Daily evaporation-transpiration cycle, Ontario willow and reed tank, 



September 11-12, 1930 103 



XXIX. Use of water between controls In Coldwater Canyon and daily maxi- 

 mum temperatures at San Bernardino during 1932 113 



XXX. Comparison of loss of water from evaporimeter and air temperature 



near mouth of Coldwater Canyon, September 7-15, 1932 118 



XXXI. East slope of Arrowhead Mountain draining into Coldwater Canyon — 120 



