2023_Pietroiusti_etal_ESD

Water balance model and analysis scripts used in Pietroiusti et al. 2023 "Possible role of anthropogenic climate change in the record-breaking 2020 Lake Victoria levels and floods" (in review).

Figure: Vanderkelen et al., 2018, HESS

Water balance model

lakevic-eea-wbm contains the water balance model component of the analysis, and can be run from the main WBM_model.py script.

This model takes as input:

1. Precipitation data, remapped using the provided grid specifications (mygrid.txt).
   • observational run: PERSIANN-CDR 1983-2020
   • attribution runs: CMIP6 GCM output historical and hist-nat bias adjusted with ISIMI3BASD from ISIMIP3b
2. Evaporation data (provided)
3. Information on soil classes, land use, basin and lake shapefiles (provided)
4. Outflow
   • observational run: semi-observational outflow (provided)
   • attribution runs: calculated using the Agreed Curve.

WBM_settings.py acts as a namelist and should be modified to run the model under different scenarios and forcings and to specify input data paths, WBM_inicon.py initiates constants in the model, WBM_inigeom.py imports shapefiles and geoinformation about Lake Victoria and the basin.

The water balance model is based on the MATLAB version developed in Vanderkelen et al. 2018, HESS, "Modelling the water balance of Lake Victoria".

Analysis of 2020 flood event

lakevic-eea-scripts contains the analysis scripts used inthe attribution study.

Scripts are divided into sections which correspond to the different sections of the analysis in the paper: 0 preprocessing, 1 analysis of observational precipitation data, 2 lake levels analysis and interpolation, 3 event definition, 4 evaluation of the WBM, 5 analysis of WB drivers, 6 GCM evaluation, 7 statistical fits for attribution and synthesis.

Data availability

Water balance model

All data necessary to run the WBM is provided in this GitHub repository (lakevic-eea-wbm/input-data/), except for precipitation NetCDF files, which are available publicly, here:

1. PERSIANN-CDR: https://www.ncei.noaa.gov/products/climate-data-records/precipitation-persiann
2. ISIMIP3b CMIP6 GCMs https://data.isimip.org/

The location of precipitation input files should be specified in WBM_settings.py.

Extreme event analysis

All analysis data that can be publicly shared is available in this repository (input data in lakevic-eea-scripts/data/input-data/ and outputs of the WBM runs that are behind the paper in lakevic-eea-wbm/output/2022).

All data included in this repository is also archived on Zenodo.

Version

Version November 2023