Water Potentials in the
Brazilian Semiarid Zone: Perspectives for an Efficient UseAldo da C. Rebouças Universidade de São Paulo Rua Eduardo Silva Magalhães, 510 Pq. Continental, CEP 05324-000, São Paulo, SP, Brasil Tel. 55-11-2682862 Fax: 55-11-8690483 E-mail: aldocr@mandic.com.br
Abstract In the central region of the Northeast, yearly rainfall is very irregular and varies between 500 and 800 mm/year. These meteorological conditions combine with the prevalence of a geological base formed by underground crystalline rock and practically impermeable, resulting in temporary rivers and semiarid soil conditions in about 10% of the national territory. The vision of permanent rivers gives us the idea of abundance, while the temporary rivers of the Northeast leave us with the impression of scarcity. It needs to be emphasized that ideas of abundance and scarcity related to visions of permanent or temporary rivers, are as wrong as the geocentricism based on the vision of the suns motion from one end to the other end of our horizon. In reality, the physical and climatic conditions predominant in Brazil's Sertão (arid and remote interior) in the Northeast, can make life difficult, demanding more diligence and more rationality using its natural resources in general and water in particular, but they are not responsible for the widely spread and tolerated poverty patterns. What is missing most in Brazil in general and in the Northeast in particular, is not water, but a prevailing cultural pattern increasing confidence and increasing the efficiency of public and private organizations dealing with water questions. The main goal of this paper is to refuse the physical and climatic determinism, which has served as justification for a culture of a water crisis in the world as well as in Brazil, as well as the draught culture in the Northeast. |