TY  - JOUR
A1  - Telteu, Camelia-Eliza
A1  - Müller Schmied, Hannes
A1  - Thiery, Wim
A1  - Leng, Guoyong
A1  - Burek, Peter
A1  - Liu, Xingcai
A1  - Boulange, Julien Eric Stanislas
A1  - Andersen, Lauren Seaby
A1  - Grillakis, Manolis
A1  - Gosling, Simon N.
A1  - Satoh, Yusuke
A1  - Rakovec, Oldrich
A1  - Stacke, Tobias
A1  - Chang, Jinfeng
A1  - Wanders, Niko
A1  - Shah, Harsh Lovekumar
A1  - Trautmann, Tim
A1  - Mao, Ganquan
A1  - Hanasaki, Naota
A1  - Koutroulis, Aristeidis
A1  - Pokhrel, Yadu
A1  - Samaniego Eguiguren, Luis Eduardo
A1  - Wada, Yoshihide
A1  - Mishra, Vimal
A1  - Liu, Junguo
A1  - Döll, Petra
A1  - Zhao, Fang
A1  - Gädeke, Anne
A1  - Rabin, Sam S.
A1  - Herz, Florian
T1  - Understanding each other's models: an introduction and a standard representation of 16 global water models to support intercomparison, improvement, and communication
T2  - Geoscientific model development
N2  - Global water models (GWMs) simulate the terrestrial water cycle on the global scale and are used to assess the impacts of climate change on freshwater systems. GWMs are developed within different modelling frameworks and consider different underlying hydrological processes, leading to varied model structures. Furthermore, the equations used to describe various processes take different forms and are generally accessible only from within the individual model codes. These factors have hindered a holistic and detailed understanding of how different models operate, yet such an understanding is crucial for explaining the results of model evaluation studies, understanding inter-model differences in their simulations, and identifying areas for future model development. This study provides a comprehensive overview of how 16 state-of-the-art GWMs are designed. We analyse water storage compartments, water flows, and human water use sectors included in models that provide simulations for the Inter-Sectoral Impact Model Intercomparison Project phase 2b (ISIMIP2b). We develop a standard writing style for the model equations to enhance model intercomparison, improvement, and communication. In this study, WaterGAP2 used the highest number of water storage compartments, 11, and CWatM used 10 compartments. Six models used six compartments, while four models (DBH, JULES-W1, Mac-PDM.20, and VIC) used the lowest number, three compartments. WaterGAP2 simulates five human water use sectors, while four models (CLM4.5, CLM5.0, LPJmL, and MPI-HM) simulate only water for the irrigation sector. We conclude that, even though hydrological processes are often based on similar equations for various processes, in the end these equations have been adjusted or models have used different values for specific parameters or specific variables. The similarities and differences found among the models analysed in this study are expected to enable us to reduce the uncertainty in multi-model ensembles, improve existing hydrological processes, and integrate new processes.
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62912
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-629122
SN  - 1991-9603
N1  - This research and open-access publication were funded by the German Federal Ministry of Education and Research (grant no. 01LS1711F).
VL  - 14
IS  - 6
SP  - 3843
EP  - 3878
PB  - Copernicus
CY  - Katlenburg-Lindau
ER  -