GEOGRAPHY'S CONTRIBUTION 215 
competent use of existing, natural cores of more intensive land 
occupancy. Since present water deficiencies in the serras are 
largely the result of improper use of the soil, such areas, as Whyte 
has pointed out, (pp. 182-188), should also be the most susceptible 
to improvement—those tracts, that is, where the soils have not 
been washed away entirely. 
Most of the general ideas advanced with regard to the poten- 
tialities of the serras apply to the eastward-facing slopes of the 
Borborema plateau, formerly hung with the Atlantic rain forest, 
but degraded by centuries of wasteful exploitation. 
In discussing the possibilities of increased production from 
present water resources, special reference should be made to the 
agricultural activities carried on at the foot of the imposing 
Ibiapaba escarpment, on the west, and at the base of a large 
isolated patch of the once continuous strata—the Chapada do 
Araripe. 
Rising to an altitude of the order of 1,000 meters (3,300 feet), 
the [biapaba is the seat of considerable condensation of moisture. 
In addition to farms strung along the crest and, to a great extent, 
dependent on rain agriculture, a strip of irrigated cropland 
Figure 11. Belt of cropland at foot of Ibiapaba escarpment, in the 
vicinity of the town of Ipu, Ceara. 
Sakae aa: 
