How evaluation of global hydrological models can help to improve credibility of river discharge projections under climate change

Autor: Krysanova, Valentina, Zaherpour, Jamal, Didovets, Iulii, Gosling, Simon N., Gerten, Dieter, Hanasaki, Naota, Müller Schmied, Hannes, Pokhrel, Yadu, Satoh, Yusuke, Tang, Qiuhong, Wada, Yoshihide, Potsdam Institute for Climate Impact Research, Potsdam, Germany, Nottingham, UK, School of Geography, University of Nottingham, Nottingham, UK, Geography Dept., Humboldt-Universität zu Berlin, Berlin, Germany, Center for Climate Change Adaptation, National Institute for Environmental Studies, Tsukuba, Japan, Senckenberg Leibniz Biodiversity and Climate Research Centre (SBiK-F), Frankfurt am Main, Germany, Department of Civil and Environmental Engineering, Michigan State University, East Lansing, USA, International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria, Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
Rok vydání: 2020
Předmět:
Zdroj: Climatic Change. 163:1353-1377
ISSN: 1573-1480
0165-0009
Popis: Importance of evaluation of global hydrological models (gHMs) before doing climate impact assessment was underlined in several studies. The main objective of this study is to evaluate the performance of six gHMs in simulating observed discharge for a set of 57 large catchments applying common metrics with thresholds for the monthly and seasonal dynamics and summarize them estimating an aggregated index of model performance for each model in each basin. One model showed a good performance, and other five showed a weak or poor performance in most of the basins. In 15 catchments, evaluation results of all models were poor. The model evaluation was supplemented by climate impact assessment for a subset of 12 representative catchments using (1) usual ensemble mean approach and (2) weighted mean approach based on model performance, and the outcomes were compared. The comparison of impacts in terms of mean monthly and mean annual discharges using two approaches has shown that in four basins, differences were negligible or small, and in eight catchments, differences in mean monthly, mean annual discharge or both were moderate to large. The spreads were notably decreased in most cases when the second method was applied. It can be concluded that for improving credibility of projections, the model evaluation and application of the weighted mean approach could be recommended, especially if the mean monthly (seasonal) impacts are of interest, whereas the ensemble mean approach could be applied for projecting the mean annual changes. The calibration of gHMs could improve their performance and, consequently, the credibility of projections.
BMBF
JSPS KAKENHI
NSFC
Databáze: OpenAIRE
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