Application of performance metrics to climate models for projecting future

Application of performance metrics to climate models for projecting future river discharge

in the Chao Phraya River basin

Satoshi Watanabe¹, Yukiko Hirabayashi¹, Shunji Kotsuki², Naota Hanasaki³, Kenji Tanaka⁴,
Cherry May R. Mateo⁵, Masashi Kiguchi⁵, Eiji Ikoma⁶, Shinjiro Kanae⁷ and Taikan Oki^5
1Institute of Engineering Innovation, The University of Tokyo, Japan
²Graduate School of Engineering, Kyoto University, Japan
³National Institute for Environmental Studies, Japan
⁴Disaster Prevention Research Institute, Kyoto University, Japan
⁵Institute of Industrial Science, The University of Tokyo, Japan
⁶Earth Observation Data Integration & Fusion Research Initiative, The University of Tokyo, Japan
⁷Department of Civil Engineering, Tokyo Institute of Technology, Japan

Abstract:
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.

KEYWORDS climate change; river discharge; Chao Phraya River basin; general circulation model (GCM); IMPAC-T Driving Dataset (IDD)

Hydrological Research Letters 8(1), 33–38 (2014)
Published online in J-STAGE (www.jstage.jst.go.jp/browse/hrl). doi: 10.3178/hrl.8.33