GROUND WATER TO OCEANS 



THE HYDROLOGIC CYCLE 



FIG. 1. The hydrologic cycle chart merits careful study. There are two points 

 in the cycle where man alters the natural course: (1) Where the rain strikes the 

 earth, man has decreased the infiltration and increased the runoff, with attendant 

 erosion, lower yields, siltation of storage basins, increase of floods, etc. (2) By 

 excessive pumping 1 of ground water for municipal, industrial, and irrigation use, 

 the water table has in many places fallen so low as to threaten such supplies. 



Man, on the whole, has never thought to compare this simple 

 physical cycle to the complex cycle of life. The energy for life is 

 carried by certain elements in soil, water and air. Few men indeed 

 have given attention and thought to the revolving of the proper 

 fraction of these elements from the point of human use back to the 

 soil, so that they maintain a perpetual flow of vigorous plant, animal, 

 and human life. 



Not enough men have given penetrating thought to preserving 

 even the soil storehouse itself, a storehouse very easily destroyed and 

 depleted. Nor has man in general considered the intricate, repetitive 

 processes by which the living soil captures, impounds, and transmits 

 to man the complex and varied materials and energies which make 

 him man. These processes are quite delicate in their system of checks 

 and balances, their interdependencies. Man has waded into them, like 

 (if we may draAV a caricature) a drunken Cro-Magnon running 

 berserk with a bull-dozer in a watch factory. 



Abnormal thinking and actions are rooted in greed, ignorance, mis- 

 information, superstition, fears, and doubtless other unfortunate fac- 

 tors. Civilized man's usage of the landscape usually evolved in just 



