GEOGRAPHY’S CONTRIBUTION PAA 
plateau represent more than 50% of the discharge of the springs 
and may even exceed 70% (6). As there is more land suitable for 
irrigation than water available for that purpose, it follows that 
the use of available water at maximum efficiency could lead to 
doubling the producing cropland. It is relevant to add that, in 
some instances, irrigation water, flowing directly down bare 
slopes causes soil depletion and erosion. 
The Geographical Approach 
To the geographer, a complex province such as the Nordeste 
signifies much more than the mere sum of its component units. 
Geography does not stop, therefore, with the analysis of each 
partial landscape, but tries to clarify the relation of the parts 
among themselves. A geographical study will bring out, for in- 
stance, the integration of farming in the serras and pastoral activi- 
ties in the sertao. It will show how cattle 1s moved to the hills after 
the harvest, to graze what residues are available, and how, in 
times of drought, both man and beast may find refuge in the 
mountains. It might go on to mention that some of the leather 
bags carried by the pack trains one meets on trails leading to the 
highlands contain manure gathered in the corrals of the sertao, 
which also furnishes a market for the produce grown on the serras 
(Figure 13). 
Figure 13. Pack train descending Ibiapaba escarpment near Ubajara, 
Ceara, with produce grown on humid rim of upland. 
