Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey

Due to climatological changes, a study was conducted in the Gediz Basin, Turkey, where agricultural production holds an important place. In the study prepared, 12 general circulation models (GCMs) were utilized under representative concentration pathway (RCP)4.5, RCP6.0, and RCP8.5 scenarios of the...

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Main Authors: Umut Kirdemir, Umut Okkan, Okan Fistikoglu
Format: Article
Language:English
Published: IWA Publishing 2022-08-01
Series:Journal of Water and Climate Change
Subjects:
Online Access:http://jwcc.iwaponline.com/content/13/8/3061
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author Umut Kirdemir
Umut Okkan
Okan Fistikoglu
author_facet Umut Kirdemir
Umut Okkan
Okan Fistikoglu
author_sort Umut Kirdemir
collection DOAJ
description Due to climatological changes, a study was conducted in the Gediz Basin, Turkey, where agricultural production holds an important place. In the study prepared, 12 general circulation models (GCMs) were utilized under representative concentration pathway (RCP)4.5, RCP6.0, and RCP8.5 scenarios of the fifth assessment report (AR5) of IPCC for the period 2015–2050. The statistical downscaling methods were employed and the projections were derived right after applying the weighted-averaged ensemble mean by the Bayesian Model Averaging (BMA) method and bias correction by equidistant quantile mapping (EDQM). The temperature-based potential evapotranspiration (PET) formulas were modified in accordance with the Penman–Monteith method and the aridity indexes were calculated by UNEP's formula. According to the projections, the mean annual temperature increases between 1.5 and 2.2 °C and the mean total annual PET increases between 5 and 8% are foreseen in the Gediz Basin for the near future. It is foreseen that a semi-arid climate regime may predominate over the region for all of the RCP scenarios under the increasing dryness in basin climate. In addition, it was obtained in the study that sub-humid climate state occurrence for all of the regions included by the basin may be unexpected in the future for the RCP8.5 scenario. The presence of semi-arid climate conditions may be more potent with the increasing trend of radiative forcing over time. HIGHLIGHTS Artificial intelligence methods were performed for downscaling.; A multi-model ensemble strategy was carried out for climate projection.; A robust bias-correction method was utilized.; Climate change forecasts were integrated with aridity concepts.; Spatio-temporal aridity changes were presented for the future term.;
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spelling doaj.art-940912444aaf477090ffcb92aa0ff0e32022-12-22T03:47:43ZengIWA PublishingJournal of Water and Climate Change2040-22442408-93542022-08-011383061308210.2166/wcc.2022.109109Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, TurkeyUmut Kirdemir0Umut Okkan1Okan Fistikoglu2 The Graduate of School of Natural and Applied Sciences, Hydraulic, Hydrology and Water Resources Division, Dokuz Eylul University, Izmir 35160, Turkey Department of Civil Engineering, Balikesir University, Balikesir, Turkey Department of Civil Engineering, Dokuz Eylul University, Izmir, Turkey Due to climatological changes, a study was conducted in the Gediz Basin, Turkey, where agricultural production holds an important place. In the study prepared, 12 general circulation models (GCMs) were utilized under representative concentration pathway (RCP)4.5, RCP6.0, and RCP8.5 scenarios of the fifth assessment report (AR5) of IPCC for the period 2015–2050. The statistical downscaling methods were employed and the projections were derived right after applying the weighted-averaged ensemble mean by the Bayesian Model Averaging (BMA) method and bias correction by equidistant quantile mapping (EDQM). The temperature-based potential evapotranspiration (PET) formulas were modified in accordance with the Penman–Monteith method and the aridity indexes were calculated by UNEP's formula. According to the projections, the mean annual temperature increases between 1.5 and 2.2 °C and the mean total annual PET increases between 5 and 8% are foreseen in the Gediz Basin for the near future. It is foreseen that a semi-arid climate regime may predominate over the region for all of the RCP scenarios under the increasing dryness in basin climate. In addition, it was obtained in the study that sub-humid climate state occurrence for all of the regions included by the basin may be unexpected in the future for the RCP8.5 scenario. The presence of semi-arid climate conditions may be more potent with the increasing trend of radiative forcing over time. HIGHLIGHTS Artificial intelligence methods were performed for downscaling.; A multi-model ensemble strategy was carried out for climate projection.; A robust bias-correction method was utilized.; Climate change forecasts were integrated with aridity concepts.; Spatio-temporal aridity changes were presented for the future term.;http://jwcc.iwaponline.com/content/13/8/3061aridity indexbayesian model averagingequidistant quantile mappingstatistical downscaling
spellingShingle Umut Kirdemir
Umut Okkan
Okan Fistikoglu
Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey
Journal of Water and Climate Change
aridity index
bayesian model averaging
equidistant quantile mapping
statistical downscaling
title Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey
title_full Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey
title_fullStr Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey
title_full_unstemmed Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey
title_short Projecting aridity from statistically downscaled and bias-corrected variables for the Gediz Basin, Turkey
title_sort projecting aridity from statistically downscaled and bias corrected variables for the gediz basin turkey
topic aridity index
bayesian model averaging
equidistant quantile mapping
statistical downscaling
url http://jwcc.iwaponline.com/content/13/8/3061
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AT umutokkan projectingaridityfromstatisticallydownscaledandbiascorrectedvariablesforthegedizbasinturkey
AT okanfistikoglu projectingaridityfromstatisticallydownscaledandbiascorrectedvariablesforthegedizbasinturkey