The eWaterCycle platform for open and FAIR computational hydrological research

The eWaterCycle platform (https://www.ewatercycle.org/) is a fully Open Source and FAIR by Design Platform where hydrologists can do computational hydrological research using their own, or others, models and data. Using eWaterCycle, computational hydrologist can focus on the hydrological part of their work, without the headache that often comes with the computational part. In eWaterCycle experiments are separated from models: experiments are build and run in Jupyter notebooks and models can be accessed as objects in these notebooks. The models themselves are hidden in (Docker) containers and accessed through an easy interface. This interface and the technology behind it that weve build allows computational hydrologists to work with (each others) models written in different programming languages without having to access that code. Currently PCRGlobWB 2.0, Hype, LISFlood, WFLOW and MARMoT are among the models supported by eWaterCycle. Furthermore, pre-processing of atmospheric forcing data is handled transparently by ESMValTool, which separates the process of selecting and standardising variables from the steps needed to make forcing compatible with a specific model. If a source of forcing data has been made ready for one model in eWaterCycle it is easy to use it for any other. If a model has been used with one forcing data source, it is easy to swap it with another. Currently ERA5 and ERA-Interim are supported in eWaterCycle. With eWaterCycle use cases such as (but not limited to!) these are now easier to implement: Comparing two models for the same region against observation data (GRDC discharge observations are standard supported) to determine which model performs best for a given research question Coupling two models (in different programming languages) to exchange information at every timestep, for example making a Running a multi-model ensemble (including adding data assimilation of observations) Previously we have announced eWaterCycle as work in progress. At the 2021 Fall Meeting we will demonstrate the release of v1.0 of the eWaterCycle platform, giving the computational hydrological community access to a platform that supports fully reproducible, open, and FAIR Hydrological modelling. https://ewatercycle.readthedocs.io/en/latest/