Intense rainfall behavior for basin in preserved Caatinga semiarid region

Abstract

The knowledge of intense precipitation is fundamental for the planning of hydrographic basins; however, it demands robust rainfall databases, still scarce in the Brazilian semiarid region. The objective of this work was to assess the intensity - duration - frequency curves (IDF) Curves in the Aiuaba Experimental Basin. Based on measurements every 5min for 16 years (2003 to 2018), IDF curves were generated for the periods of 5min, 30min, 1h, 2h, 3h, 6h, 12h, 18h, and 24h. The parameters of the Otto Pfafstetter equation for the IDF curves was calibrated as well. From the investigation, we concluded that: the IDF curves (inedited for the Inhamuns region, CE) are compatible with those of other studies in semiarid regions and indicated to be a macro-regional property; the erosivity indicated a maximum value for rainfall of duration equal to 3 h, being this a combined effect of high intensity and high kinetic energy. This conclusion calls for further studies, ratifying the need for hydrological models capable of more accurately identifying the sub-daily variations in hydrological processes.