The critical role of the routing scheme in simulating peak river discharge in global hydrological models

作者：Fang Zhao, Ted Veldkamp, Katja Frieler, Jacob Schewe, Sebastian Ostberg, Sven Norman Willner, Bernhard Schauberger, Simon Newland Gosling, Hannes Müller Schmied, Felix Theodor Portmann, Guoyong Leng, Maoyi Huang, Xingcai Liu, Qiuhong Tang, Naota Hanasaki, Hester Biemans, Dieter Gerten, Yusuke Satoh, Yadu Nath POKHREL, Tobias Stacke, Philippe Ciais, Jinfeng Chang, Agnès Ducharne, Matthieu Guimberteau, Yoshihide Wada, Hyungjun Kim, Dai Yamazaki · 发表于：Environmental Research Letters · 年份：2017 · DOI：10.1088/1748-9326/aa7250 · 被引用次数：184 · 研究领域：Flood Risk Assessment and Management、Hydrology and Watershed Management Studies、Climate variability and models

Global hydrological models (GHMs) have been applied to assess global flood hazards, but their capacity to capture the timing and amplitude of peak river discharge—which is crucial in flood simulations—has traditionally not been the focus of examination. Here we evaluate to what degree the choice of river routing scheme affects simulations of peak discharge and may help to provide better agreement with observations. To this end we use runoff and discharge simulations of nine GHMs forced by observational climate data (1971–2010) within the ISIMIP2a project. The runoff simulations were used as input for the global river routing model CaMa-Flood. The simulated daily discharge was compared to the discharge generated by each GHM using its native river routing scheme. For each GHM both versions of simulated discharge were compared to monthly and daily discharge observations from 1701 GRDC stations as a benchmark. CaMa-Flood routing shows a general reduction of peak river discharge and a delay of about two to three weeks in its occurrence, likely induced by the buffering capacity of floodplain reservoirs. For a majority of river basins, discharge produced by CaMa-Flood resulted in a better agreement with observations. In particular, maximum daily discharge was adjusted, with a multi-model averaged reduction in bias over about 2/3 of the analysed basin area. The increase in agreement was obtained in both managed and near-natural basins. Overall, this study demonstrates the importance ...