Assessment of MC&amp;MCMC uncertainty analysis frameworks on SWAT model by focusing on future runoff prediction in a mountainous watershed via CMIP5 models

Armin Ahmadi,Mohsen Pourreza-Bilondi,Amirhosein Aghakhani Afshar,Vahid Nourani,A A Besalatpour

doi:10.2166/wcc.2019.122

Abstract

AbstractThe river situation in a dry or semi-dry area is extremely affected by climate change and precipitation patterns. In this study, the impact of climate alteration on runoff in Kashafrood River Basin (KRB) in Iran was investigated using the Soil and Water Assessment Tool (SWAT) in historical and three future period times. The runoff was studied by MIROC-ESM and GFDL-ESM2G models as the outputs of general circulation models (GCMs) in the Coupled Model Intercomparison Project Phase 5 (CMIP5) by two representative concentration pathway (RCP) scenarios (RCP2.6 and RCP8.5). The DiffeRential Evolution Adaptive Metropolis (DREAM-ZS) was used to calibrate the hydrological model parameters in different sub-basins. Using DREAM-ZS algorithm, realistic values were obtained for the parameters related to runoff simulation in the SWAT model. In this area, results show that runoff in GFDL-ESM2G in both RCPs (2.6 and 8.5) in comparing future periods with the historical period is increased about 232–383% and in MIROC-ESM tends to increase around 87–292%. Furthermore, GFDL-ESM2G compared to MIROC-ESM in RCP2.6 (RCP8.5) in near, intermediate, and far future periods shows that the value of runoff increases 59.6% (23.0%), 100.2% (35.1%), and 42.5% (65.3%), respectively.

Highlights

The impact of climate change on the availability of water resources has been attracting the attention of researchers throughout the world (Faramarzi et al ; Rodrigues et al ; Zuo et al )
The results showed that GFDL-ESM2G and MIROC-ESM might be chosen as the best climate models for comparing and predicting the effects of future climate change on the runoff component in the Kashafrood River Basin (KRB)
The results show that in the near and intermediate periods, by both models under RCP8.5, simulated runoff will be higher than RCP2.6, while in the far future under RCP2.6, the mean annual of the simulated runoff will be higher than that in the other scenario

Summary

Introduction

The impact of climate change on the availability of water resources has been attracting the attention of researchers throughout the world (Faramarzi et al ; Rodrigues et al ; Zuo et al ). Zuo et al ) and exacerbated water scarcity in dry and semi-dry regions. There is a great deal of concern among researchers about the increasing threat of water scarcity in the region and at global scale (Vörösmarty et al ). Ahmadi et al | Runoff prediction via CMIP5 models with calibrated SWAT model

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Conclusion