Historic reconstructions of daily river flow for 303 UK catchments (1891-2015)

The GR4J model (v 1.0.2) was run over the calibration period (1982-2014) using 500,000 Latin Hypercube Sampled model parameter sets. These model parameters were assessed against observations from the National River Flow Archive (NRFA). For two catchments (the Thames at Kingston, and the Lea at Feildes Weir) the model was also calibrated against naturalised flows. The model was calibrated using a multi-objective approach comprising of 6 evaluation metrics: Nash Sutcliffe Efficiency (NSE), NSE on log flows (log NSE), Mean Absolute Percent Error (MAPE), Absolute Percent Bias (PBIAS), Absolute Percent Error in Mean Annual Minimum flows over a 30 day accumulation period (MAM30), and Absolute Percent Error in the flow exceeded 95% of the time (Q95).

The 500,000 model runs were then ranked by each evaluation metric, the ranks were summed, and the runs were reordered according to this final rank. Finally, in order to prevent uneven trade-offs between metrics, the runs were re-ordered according to thresholds of acceptability.
Reconstructed flow timeseries were then run for the top 500 ranking model parameter sets, using PET (Potential Evapotranspiration) (Tanguy et al., 2017: doi https://doi.org/10.5285/17b9c4f7-1c30-4b6f-b2fe-f7780159939c), and reconstructed daily rainfall data, provided by the UK Met Office.
The modelled data, and the supporting metadata files, were exported from the R software programme as comma separated value files (.csv), and ingested into the EIDC in this format.

This dataset is included in the following collections

Historic droughts: hydro-meteorological data outputs