Journal of Water and Climate Change (Mar 2022)

Deciphering the projected changes in CMIP-6 based precipitation simulations over the Krishna River Basin

  • Suram Anil,
  • P. Anand Raj

DOI
https://doi.org/10.2166/wcc.2022.399
Journal volume & issue
Vol. 13, no. 3
pp. 1389 – 1407

Abstract

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The impact of climate change on the Krishna River Basin (KRB) is significant due to the semi-arid nature of the basin. Herein, 21 global climate models (GCMs) of Coupled Model Intercomparison Project Phase 6 (CMIP6) were examined to simulate the historical monthly precipitation over the 1951–2014 period in the KRB. The symmetrical uncertainty (SU) method and the multi-criteria decision method (MCDM) were employed to select the suitable GCMs for projecting possible changes in precipitation over the KRB. The biases in the climate projections were removed by using the empirical quantile mapping method. The reliability ensemble averaging (REA) method was used to generate the multi-model ensemble (MME) mean of projections and to analyse the spatio-temporal changes of precipitation under different shared socioeconomic pathways (SSPs). BCC-CSM2-MR, IPSL-CM6A-LR, MIROC6, INM-CM5-0, and MPI-ESM1-2-HR were found to be the most suitable GCMs for the KRB. The MME mean of the chosen GCMs showed significant changes in precipitation projection that occurs for a far future period (2071–2100) over the KRB. The projection changes of precipitation range from −36.72 to 83.05% and −37.68 to 95.75% for the annual and monsoon periods, respectively, for various SSPs. Monsoon climate projections show higher changes compared with the annual climate projections, which reveals that precipitation concentration is more during the monsoon period over the KRB. HIGHLIGHTS Spatio-temporal analysis of CMIP-6 based precipitation projections over KRB was carried out.; One of the most effective algorithm, Symmetric Uncertainty is used to select suitable GCMs from CMIP 6 models.; Selected top five GCM outputs were forced to develop MME using REA method.; The possible changes in precipitation projections are attributed to Koppen Climate zones in KRB.; Significant changes were occurred in far-future in BSh climate zone.;

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