Evaluating uncertainty in climate change impacts on peak discharge and flood volume in the Qaran Talar watershed, Iran

This study evaluates the effects of climate change (CC) on runoff properties over the case study of the Qaran Talar watershed located in Iran. To consider the two main sources of uncertainty, i.e., Greenhouse Gases emission (GHG) scenarios and outputs of Atmosphere-Ocean General Circulation Models (...

Full description

Bibliographic Details
Main Authors: Toktam Imani, Mahdi Delghandi, Samad Emamgholizadeh, Zahra Ganji-Noroozi
Format: Article
Language:English
Published: IWA Publishing 2023-04-01
Series:Journal of Water and Climate Change
Subjects:
Online Access:http://jwcc.iwaponline.com/content/14/4/1300
Description
Summary:This study evaluates the effects of climate change (CC) on runoff properties over the case study of the Qaran Talar watershed located in Iran. To consider the two main sources of uncertainty, i.e., Greenhouse Gases emission (GHG) scenarios and outputs of Atmosphere-Ocean General Circulation Models (AOGCMs), a daily rainfall time series was generated for two future periods (2021-2050 and 2070-2099) at three risk levels of 0.1, 0.25 and 0.50. 22 AOGCMs outputs following two emission scenarios (RCP4.5 and RCP8.5) were used. The results showed that the uncertainty of climate change scenarios was primarily owing to the uncertainty of GCMs outputs. Regarding the 2021-2050 period, under both emission scenarios, the increases in peak discharge and flood volume (FV) were estimated to reach 70, 50, and 30% at three risk levels of 0.1, 0.25 and 0.50, respectively, compared to the recent past period. As the current century draws to a close, the difference between the results of the two emission scenarios becomes apparent so that in the far-future period (2070-2099), the RCP8.5 scenario estimates and FV more than the RCP4.5 scenario does. Additionally, it was found that the uncertainty caused by AOGCMs was more than that by GHG emission scenarios. HIGHLIGHTS The impacts of CC on flood hydrographs were discussed.; CC leads to an increasing trend in and FV.; RCP8.5 predicted a greater increase in and FV compared to RCP4.5.; The uncertainty caused by AOGCMs is more compared to GHG scenarios.;
ISSN:2040-2244
2408-9354