Application of performance metrics to climate models for projecting future river discharge in the Chao Phraya River basin

Future river discharge in the Chao Phraya River basin was projected based on the performance of multiple General Circulation Models (GCMs). We developed a bias-corrected future climate dataset termed IDD (IMPAC-T Driving Dataset) under which the H08 hydrological model was used to project future river discharge. The IDD enabled us to conduct a projection that considered the spread in projections derived from multiple GCMs. Multiple performance-based projections were obtained using the correlation of monsoon precipitation between GCMs and several observations. The performance-based projections indicated that future river discharge in September increased 60%–90% above that of the retrospective simulation. Our results highlight the importance of appropriate evaluation for the performance of GCMs.