Climate change impacts on intensity duration frequency curves of precipitation: A case study of Shiraz synoptic station, Iran

A.roshan A.Roshan,H Sedghi H Sedghi,R.a.sharifan R.A.Sharifan,J.porhemmat J.Porhemmat

doi:10.54386/jam.v21i2.226

A.roshan A.Roshan, H Sedghi H Sedghi + Show 2 more

Open Access

https://doi.org/10.54386/jam.v21i2.226

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Abstract

Intensity-duration-frequency (IDF) curves are among the standard design tools for many engineering applications such as urban drainage management. Since climate change may considerably affect precipitation, updating of IDF curves is highly necessary. The present study aims to examine the impacts of climate change on IDF curves of Shiraz synoptic station using downscaled outputs of Hadcm3 AOGCM under various emission scenarios (A1B, A2,B1) applying larswg-5 model for the period of 2046 to 2065. The fitted Gumbel distribution was used to estimate the maximum short-term precipitation quantiles in the base period (1968-2000) and the verified empirical Bell type equation was used for the future period. The results show that the mean of maximum daily precipitation and annual precipitation will decrease in the future. Also, the maximum precipitation intensities up to 60 min duration will reducefrom 0.15 mm hr-1 to about 10.79 mm hr-1 compared to the observed period in all returns periods and various scenarios. Overall, there were no tangible changes in intensities for durations higher than 60 min. The highest reduction in precipitation intensity would be at the 20 min duration with 100-year return period in the A2 scenario.

Highlights

The precipitation intensity-duration-frequency (IDF) curves are one of the main tools to design of hydrosystems and to estimate the design flow, especially in ungauged areas (Afrin et al 2015)
Among most important methods in this regard are method of fragment (MOF) (Fadhel et al 2017;Pereira et al 2014;Solaiman and Simonovic 2011), constant scale method (Afrin et al 2015;Rodriguez et al 2014),constant climate change factor (Rodriguez et al 2014), Equidistant quantiles (Singh et al 2016), hourly change factor (Zahmatkesh et al 2015), disaggregation based on observed severe daily precipitation histograms (Akbari et al 2015) and regional Bell type equations (Bakhtiari et al 2015) that estimate maximum short-term
(2004)) in Iran like empirical Bell equation (Bell 1969) the general equation RTt = A.tB.RT60has been presented, where RT is a maximum hourlyprecipitation in T year return period and A and B are constant coefficients calibrated regionally using the results of storm analysis in 7 regions of Iran

Summary

Introduction

The precipitation intensity-duration-frequency (IDF) curves are one of the main tools to design of hydrosystems and to estimate the design flow, especially in ungauged areas (Afrin et al 2015). Extraction of base period maximum short-term precipitations quantiles (RT ) and IDF curves t

Results

Conclusion