Climate changes impact estimation on urban drainage system located in low latitudes districts: a study case in Fortaleza-CE

Marcos Abílio Medeiros De Sabóia,Cleiton Da Silva Silveira,Luiz Martins De Araújo Júnior,Francisco De Assis De Souza Filho

doi:10.1590/2318-0331.011716074

Marcos Abílio Medeiros De Sabóia, Cleiton Da Silva Silveira + Show 2 more

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https://doi.org/10.1590/2318-0331.011716074

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Abstract

ABSTRACT The observed changes in extreme weather events reflect the influence of climate change caused by anthropogenic factors, in addition to natural climate variability. According to future climate projections, the increase in the average surface temperature will cause major changes in the average annual rainfall of almost the entire planet. The primary objective of this study is to evaluate the impact of possible scenarios of climate change on urban drainage system in locations situated at low latitudes. The specific location of the study was one of the Rio Cocó sub-basins in the city of Fortaleza-CE. It was used rainfall data generated by 6 (six) different global circulation models: bcc-CSM1, CanESM2, CCSM4, CESM1-CAM5, inmcm4 and MIROC5. These data were extracted and interpolated to the city of Fortaleza-CE. This information was used in order to generate new IDF equations designed for the future, by using the “Equidistance Quantile Matching Method”, based on climate projections RCP 4.5 and RCP 8.5. The new values of rainfall generated by these new IDF curves were used as input data to HEC-HMS program, which is capable of calculating flow and volume disposed in a particular basin. The results showed that large increases in flow rates and volumes disposed in the analyzed drainage system will occur, and that the RCP 8.5 scenario presented even more pronounced values than the ones generated by the scenario RCP 4.5.

Highlights

In order to avoid possible flooding, an urban drainage system is required for capturing and conducting stormwater
According to the results based on the outputs of sets of climate models, it can be inferred that in both studied scenarios, RCP 4.5 and RCP 8.5, most Global Circulation Models (GCM) used point to an increase in the peak flows and the volumes drained by the studied drainage systems, diverging in its magnitude
Based on what four of six analyzed GCMs point out, the grater the number associated with RCP is, that is, the higher the concentration of greenhouse gases in the atmosphere, the more the models point to an increase in the intensity of extreme events, and an increase in the costs of implementing the urban drainage system

Summary

Introduction

In order to avoid possible flooding, an urban drainage system is required for capturing and conducting stormwater. Changes in maximum precipitation intensity associated with climate changes have the potential to overburden drainage systems, which can lead to flooding, local pathway impairment, worsening of waterborne diseases, and increased risk of human and material losses as well. Precipitation patterns are directly affected by the change in global mean temperature, which is strongly related to the increase of gases in the atmosphere, such as: carbon dioxide, methane and nitrous oxide (IPCC, 2013). Increases in total rainfall volumes, as well as their intensities, can cause strong impacts on urban drainage systems. Due to global warming and as a result of anthropogenic actions, Allan and Soden (2008) suggest that extreme precipitations events will become more common. Marengo et al (2013) indicate that these extreme events should become more frequent and intense in Brazil

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