EFAS v4.0 calibration discharge data

Daily and 6-hourly stream flow observations from 1137 stations in 215 different catchments in the Pan-European EFAS domain were selected for the LISFLOOD model calibration and evaluation for EFAS v4.0, 406 with 6-hourly data and 731 with daily data.

EFAS discharge observations are collected by EFAS Hydrological Data Collection Centre (HDCC) and are shared through HDCC database and API. Prior to calibration, available discharge data were quality checked and sanitised to detect and remove outliers and suspicious zeros (i.e. in large rivers where no natural phenomena could explain discharge equal to zero). To remove outliers, an increase/decrease rate >500% between two consecutive data was used for daily data, >350% for 6-hrs data. For few stations smaller limits were also used and data from previous steps where considered when data in adjacent steps where missing. 

Observed discharge data for the period 1990-2017 were considered for the calibration, because corresponding meteorological forcings were available. For each calibration station, minimum 4 years of discharge data are used for calibration. For those stations whose time series came with gaps and missing data, the calibration period was extended (if possible) to include the number of steps corresponding to 4 years. Exceptions were made for stations with nearly 4 years of data that could improve the spatial coverage of calibrated catchments in EFAS pan-European domain.

The discharge record was split in two for calibration and validation purposes. If the record was shorter than eight years, four years were used for calibration and the remaining years were used for validation. If the record was equal to or longer than eight years, half was used for calibration and half for validation. The most recent period was used for calibration because earlier forcing data and discharge observations have greater uncertainty.

Figure 2.1 - EFAS v4.0 - Available discharge data over the period 1990-2017 for daily (red) and 6-hourly (blue) stations.

Figure 2.2 - EFAS v4.0 - Selected discharge data for LISFLOOD calibration over the period 1990-2017 for daily (red) and 6-hourly (blue) stations.

Figure 2.3 - EFAS v4.0 - Spatial distribution of available discharge data over the period 1990-2017 [number of years]. Dots size represents drainage area of the station.

Figure 2.4 EFAS v4.0 - Spatial distribution of selected discharge data for LISFLOOD calibration over the period 1990-2017 [number of years]. Dots size represents drainage area of the station.

Figure 2.5 - EFAS v4.0 - Spatial distribution of selected discharge data for LISFLOOD calibration over the period 1990-2017 for a) 6-hourly stations and b) daily stations [number of years]. Dots size represents drainage area of the station.