Avaliação interanual das anomalias de chuvas da bacia hidrográfica do Rio Mundaú - Ceará

Abstract

This work evaluates the temporal-spatial variability of the rainfall in the Mundaú River basin - Ceará, seeking for relationships between ongoing climate changes on a global scale and possible changes in regional scale and its affects in the local hydrometeorology. For the accomplishment of this work, historical data series of precipitations from raingauge stations of the FUNCEME located in the vinicity of the mountain of Itapipoca, Sertão and in the coastal region along the valley of the Mundaú River basin were analyzed from 1976 to 2017. Statistical analysis was performed to obtain the means and the standard deviations, in addition to performing trend and correlation tests. The rainfall variability over time was analyzed through the IAC – Rainfall Anomalies Index, allowing the identification of the period with positive anomalies with Sea Surface Temperature in central Pacific Ocean. The IAC show a slight predominance of negative rainfall anomalies, with cycles of dry years and wet years, the last dry period covered 2012 to 2016 being the longest dry period of the historical record, even though no consistent changes are identified in the local climate from the time series studied. Two of the four stations analyzed presented negative trends, but the overall basin mean had almost zero trend. It was observed increase of negative anomalies in all the stations and a significant relation of negative anomalies during warm phase of the ENSO.