Relação entre os índices de seca e os volumes armazenados no reservatório do município de Várzea Alegre - CE

Abstract

When speaking about Northeast Brazil, it is commonly associated with the drought phenomenon, although this is not a characteristic inherent only to this region. However, this association is valid due to the great recurrence with which this climatic phenomenon reach the Northeast. The state of Ceará, more precisely the city of Várzea Alegre, inserted in the region already mentioned has been presenting a picture of water scarcity since the year 2012. Public policies are adopted to mitigate the effects of the drought, but are, for the most part, emergency actions, long-term plans are still a minority in actions in this area. The need to adopt actions to prevent and assist droughts is seen, enabling the authorities to have information and tools capable of assisting in reducing the impacts caused by the water deficits faced by the region. Before any action of prevention or mitigation to be taken, one must understand the phenomenon. First, it must be accepted that there is no single definition for drought, (several definitions are found in the literature), what is commonly perceived in these definitions is that all references to drought originate from rainfall deficits, which will light the variation in the concepts (definitions) is how long this deficit will last. Understanding that the time scale is a factor of relevance in the characterization of the natural phenomenon of the drought, the tool proposed here for analysis is the SPI (Standardized Precipitation Index), whose results were analyzed for several time scales (1, 3, 6 and 12 months). The results were evaluated through coefficients and tests that measure their consistency and made the proper interpretations. SPI has been shown to be an appropriate tool for the quantification of drought events in the most varied time scales, showing that it can be used by the public authority of Várzea Alegre in the design of plans to mitigate the effects of drought.