326 THE FUTURE OF ARID LANDS 
the industrial revolution, became a property with a quite perma- 
nent value. Fluctuations in value occurred only through discovery 
of mineral rights, general fluctuations in the economy, and through 
an encroachment of urban areas. In arid lands, however, all these 
factors are overshadowed by the overwhelming importance of 
water to any utilization of the land. Accordingly the value of 
lands in arid regions is subject to another major fluctuation, 
namely, that in the availability of water. The predictability of 
land, values, therefore, unlike those in humid regions, becomes as 
uncertain as long range predictions of weather and climate, and, 
as we have seen in more than one short range cycle in our own 
time, economic displacements of great magnitude can occur 
through this unpredictability. When an economy contains a sig- 
nificant segment as an arid land component, the fluctuations of 
the latter may initiate sympathetic fluctuations of more serious 
consequence in the general economy. 
“Oasis Economy” 
Except for some variation in place utility and in inherent pro- 
ductivity, in the humid regions the value of land changes gradually 
from point to point and provides a broad gridwork on which 
human activities may be placed with considerable freedom of 
choice. In the arid regions, however, as we have just discussed, 
except for mineral values, the value of the land is insignificant in 
the absence of water, and thus the condition arises that the value 
of a given ptece of land is not inherent in the land but ts the value of 
the available water at that point. Despite this major economic fact 
there has been no readjustment of the economic principles de- 
veloped in humid regions, in that our laws and economic system 
still consider land the primary value in all areas. 
More particularly, unlike humid areas where the value of land 
varies gradually from point to point, in arid areas the value of 
land changes abruptly at the boundaries of water availability. 
Although not caused completely by availability of water, this 
characteristic of arid land population distribution 1s one of the 
first things noted by the humid-land traveler in arid regions. Arid 
land population and activity distribution is characterized by a few 
spots of population separated from each other by great distances 
