Flood events and flood types for a large sample of catchments in Europe

Author: Svenja Fischer and Manuela Brunner
Owner: Manuela Brunner
Last update: 28.09.2022

This dataset provides flood events and flood types for the period 1981–2012 for a selection of 863 catchments in Europe, which are part of the Global Runoff Data Centre
database (GRDC) and are uninfluenced by large dams. 
It accompanies an analysis by Brunner and Fischer (2022), which assesses how spatial flood connectedness varies by flood generation process using a flood event classification scheme distinguishing between three rainfall-driven and two snowmelt-influenced flood types.

Dataset components:

(1) Shapefile of 863 catchment outlet locations: catchment_outlets.shp
The shapefile meta data contains information on: 
- grdc_no: catchment ID referring to the GRDC database and used as a reference for the data files in (2)
- wmo_reg: WMO region
- sub_reg: WMO subregion
- river: name of the river
- station: name of the measurement station
- country: country
- lat: latitude of catchment outlet
- long: longitude of catchment outlet
- area: catchment area in km2
- altitude: mean elevation of catchment in m.a.s.l.
- d_start: first year of record with daily data in the GRDC database
- d_end: last year of record with daily data in the GRDC database
- d_yrs: number of years with daily streamflow data available through the GRDC database

(2) Flood events and their characteristics for the 863 catchments (folder flood_events).
Flood events were identified using the variance-based separation algorithm by Fischer et al., 2021
File name structure: _Flood_types.csv
(a) Begin (YYYY-MM-DD): date of the start of the flood event
(b) End (YYYY-MM-DD): date of end of the flood event
(c) Peak_date (YYYY-MM-DD): date of flood peak occurrence during that event
(d) Sum_SM: soil moisture (mm/event)
(d) Sum_N: precipitation sum (mm/event)
(e) dir_Volume: direct runoff volume (million m³/event)
(f) HQ_dir: direct runoff peak flow (m³/s)
(g) PSI_SM: runoff coefficient 
(h) TQDir: flood timescale between direct peak and volume (hours)
(i) SM_rel: relative proportion of snowmelt with respect to the total amount of flood-generating water
(j) HQ: peak discharge (m³/s)
(k) Type: flood type according to classification scheme proposed by Fischer et al. 2019

Legend for flood types:
R1: flood events with high flood peaks and small volumes, associated with heavy rainfall of high intensity 
R2: flood events with moderate peak and volume, associated with medium-duration rainfall of uniform intensity
R3: flood events with large volume, associated with long, successive rainfall events
S1: rain-on-snow floods, where rainfall falls on a snow cover, i.e. associated with high amounts of rainfall but less snow melt compared to snow melt floods
S2: snow melt floods, where the snow cover melts, i.e. events with a high amount of snow melt but no or only a small amount of rainfall

Related publications:
Brunner & Fischer (2022). Snow-influenced floods are more strongly connected in space than purely rainfall-driven floods. Environmental Research Letters. https://iopscience.iop.org/article/10.1088/1748-9326/ac948f
​GRDC database: GRDC. (2019). Global runoff data centre. River Discharge Data. https://www.bafg.de/GRDC/EN/02_srvcs/21_tmsrs/riverdischarge_node.html 
Fischer et al. 2019: ​Fischer, S., Schumann, A., & Bühler, P. (2019). Timescale-based flood typing to estimate temporal changes in flood frequencies. Hydrological Sciences Journal, 64(15), 1867–1892. https://doi.org/10.1080/02626667.2019.1679376 
Fischer et al. 2021: ​Fischer, S., Schumann, A., & Bühler, P. (2021). A statistics-based automated flood event separation. Journal of Hydrology X, 10, 100070. https://doi.org/10.1016/j.hydroa.2020.100070