Érica Cristine Medeiros Nobre Machado,Osvalcelio Merces Furtunato,Eber José de Andrade Pinto, Universidade Federal de Campina Grande, unidade acadêmica de engenharia ambiental, ericacristine@gmail.com
Abstract:
The high spatial and temporal variability of the rainfall is mainly determined by general atmospheric circulation, but, local features, such vegetation and topography are also decisive. This paper presents Rio de Contas Basin’s isohyets maps, with the support from 30 precipitations points in an area of about 56,290 km², in state of Bahia, Northeast of Brazil. The period of sampling starts in 1975 and finished in 2007. ArcView® was the software used to definition equal precipitation´s lines and Krigagem was the method used to interpolation the average precipitations points. Results are consistent with the mechanisms of formation of basin´s rainfall. Precipitations were from 531.04 to 2,356.23 mm/year and the highest precipitations regions occurred in the coastal area, whose intensity gradually decreases as into to moves into the inner regions of the basin and increases slightly when approaching from the Chapada Diamantina. The rainiest trimester in the coastal regions starts in April and ends in June, and the inner regions of the basin the rainiest trimester occur from October to November and from January to March.
Key-words: variability rainfall, isohyets maps, krigagem.