Impact of climate change on the estimated capacity required of detention reservoirs for Fortaleza (CE)

Abstract

The study aims to: estimate the required capacity of detention reservoirs for the return times of 5, 10 and 25 years for each of the three micro-basins: A3.5 – Vertente Marítima; B1.4 - Coco, and C5.2 - Maranguapinho, using the generalized methodology from particularized equations for Fortaleza (CE) and perform the pre-dimensioning from the new IDF equations for the current scenario and those prospected for the future using global circulation models in different climate change scenarios – representative concentration pathways – optimistic (RCP 4.5) and pessimistic (RCP 8.5). It was observed the relevant impact of global warming on the volume to be stored, the maximum flow and the specific volume for the IDF of the global circulation model - CESM1-CAM5, when compared to the current IDF and the BCC-CSM1 model in both scenarios. Which may indicate the need to design a more robust and costly structure to mitigate the effects of climate extremes. On the contrary, the IDF results of the BCC-CSM1 model are lower for both the 4.5 and 8.5 levels, in relation to the current IDF and the CESM1-CAM5 model, implying a possible undersized. Bearing in mind that climate change and the various models of global circulation with their different responses, bring difficulties for decision-making, presenting an uncertain and challenging future for decision-making processes. We recommend future studies associating circulation models global and other types of isolated compensatory techniques.