Synopsis HydroPy is a global hydrological model combining hydrological land surface processes and river routing. It is based on the older Max Planck Institut for Meteorologys Hydrology Model (MPI-HM), however it is fully revised and written in Python. This model is actively developed and will get regular updates. Currently, its development is founded by the Helmholtz-Zentrum Geesthacht and the DAAD project The Ocean's Alkalinity. Motivation While the older Fortran version of the MPI-HM is a very fast model, its development is hampered by an inflexible structure and a large overhead whenever new processes are implemented. Additionally, it only outputs service format data and time consuming post-processing is needed to produce netCDF files. The python version uses much more high-level routines and is strongly object-orienting enabling a much faster and easier development. HydroPy is the official successor of the MPI-HM. Installation HydroPy requires a python 3.x environment with numpy, netCDF4, xarray and termcolor packages installed. The most convinient way would be to setup an Anaconda installation and create a new environment dedicated to the hydropy model, e.g. conda create -n hydropy numpy xarray netCDF4 termcolor and switch to this environment using conda activate hydropy Run HydroPy HydroPy is called from command line using the main function `./hydro.py`. Required options are the paths to a netCDF file containing meteorological forcing data and a setup file containing the path of the land surface conditions file, and optionally further path information and model parameters: ./hydro.py -f forcing.nc -s setup.ini The forcing files has to provide the variables TSurf [K], Precip [kg m-2 s-1], and PET [kg m-2 s-1] at a temporal resolution of 1 day and a spatial resolution similar to the land surface conditions file. The setup file needs to be constructed with one pair of options and values per line, separated by a colon, e.g. para : hydropy_landsurface_parameter_v1.0.0.nc opt1 : val1 opt2 : val2 A full list of all available options with either the default or user defined values (if set in the setup.ini file) can be printed with ./hydro.py -s setup.ini -p Further options can be displayed with hydro.py --help Documentation and References A documentation paper is currently under preparation for publication in GMD. An example land surface parameter dataset at 0.5 degree can be found here. Contributors Tobias Stacke (tobias.stacke@hzg.de) Stefan Hagemann (stefan.hagemann@hzg.de) License HydroPy Copyright (C) 2021 Tobias Stacke This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.