Comparison of CMIP5 and CMIP6 GCM performance for flood projections in the Mekong River Basin

Mekong River Basin. The Coupled Model Intercomparison Project Phase 6 (CMIP6) recently announced an updated version of general circulation models (GCMs). This study investigated the performance improved CMIP6 over those CMIP5 with respect to precipitation and flood representations in Basin (MRB). correlation error comparison from referenced exhibited a significant improvement peak value representation. Hence, impacts climate change on future floods MRB were simulated assessed using distributed rainfall–runoff–inundation model. results indicated that had higher lower coefficient than CMIP5. Similarly, simulation GCM ensembles monthly discharge comparable average observations, whereas underestimated simulations. mean annual 37,220 m3/s (CMIP5) 45,423 compared 43,521 (observation). projections increase at Chiang Saen, Vientiane, Pakse, Kratie stations by 10–15%, 20–22%, 24–29% for SSP2-4.5 scenario, 10–18%, 24–29%, 41–54% SSP5-8.5 scenario near (2026–2050), mid-future (2051–2075), far (2076–2100), respectively. statistical K-S test showed changes all projected periods p-value < 0.01.