Output of the Land Surface Model ORCHIDEE over river catchments in Europe, run with GSWP3 and synthetic forcings where the precipitation is modified

# Description of the data file

This dataset contains the main outputs used for the results of the article: "Budyko framework based analysis of the effect of climate change on watershed evaporation efficiency and its impact on discharge over Europe", by Julie Collignan, Jan Polcher, Sophie Bastin, Pere Quintana-Segui, accepted by the journal *Water Resources Research*.

This study uses the outputs of a land surface model (LSM), forced with differentan atmospheric datasets from 1901 to 2010. The atmospheric dataset are based on GSWP3 (Hyungjun, K. (2017), doi: 10.20783/DIAS.501) and was modified to create synthetic forcings with different precipitation characteristics (annual average, intra-annual distribution). The LSM was run with all synthetic forcings, and the outputs (precipitation, evapotranspiration, potential evapotranspiration, discharge) were integrated at the level of each river basin which are sampled by gauging stationss. These outputs are used to fit a parametric equation of the Budyko framework to decompose the partial trends in discharge and the relative weight of the different climatic components.

# Details of the variables and attribute of the file

This study was led over 2196 river basins over Europe. 

For each catchment used in the study, it gathers:
- name of the station at the outlet *name*
- name of the river associated *rivers*
- lat/lon of the station *Localisation*
- upstream area of the catchment *upstream*
- Observed discharge (data not used in the article) *DisObs*
These data come from three different sources:
* *Global Runoff Data Centre (GRDC)*, https://www.bafg.de/GRDC/EN/02_srvcs/21_tmsrs/riverdischarge_node.html ;
* *Ministere de lenergie* (February 2021), https://www.hydro.eaufrance.fr/" ;
* *Geoportal of Spain Ministerio (Ministerio de Agricultura, pesca y alimentacion, Ministerio para la transicion ecologica y el reto demografico*, 2020

Each catchment was projected on the grid of the LSM ORCHIDEE (*IPSL, https://orchidee.ipsl.fr/*) during the construction of its river routing system. More details are given in the associated article.

The results for four different run of the LSM are included in this dataset. This dataset gathers for each run:
* Precipitation *P*
* Evapotranspiration *E*
* Potential evapotranspiration *PET*
* Discharge *DisMod*

The different synthetic forcings are:
- the reference forcing with the un-modified atmospheric dataset: *the Global Soil Wetness Project Phase 3 (GSWP3)*, Hyungjun, K. (2017), doi: 10.20783/DIAS.501
- *f2000*: A forcing where all 3h values of $P$ are set to the values of the year 2000 (September 1999 to September 2000) for each year. Therefore, all components of $P$ (average and intra-annual variations) are set constant.
- *cstmean*: A forcing for which we keep the relative intra-annual distribution of $P$ of each year, but where the average $P$ of each year is set constant. The 3h values of $P$ are scaled so the hydrological year average is set to the one of the year 2000 (September 1999 to September 2000).
- *cstintravar*: A forcing for which we keep the annual average of $P$ for each year, but where the relative intra-annual distribution of $P$ is set constant. The 3h values of $P$ are set to the values of the year 2000 (September 1999 to September 2000) for each year and then scaled over each hydrological year so the yearly average is set to the one of the corresponding years in the reference forcing.
\end{itemize}

## ncdump -h Filename.nc

```
dimensions:
    basins = 2196 ;
    years = UNLIMITED ; // (110 currently)
    loc = 2 ;
    lenstr = 57 ;
variables:
    short years(years) ;
        years:long_name = "Years" ;
        years:units = "year" ;
    char names(basins, lenstr) ;
        names:long_name = "Name of the station at the catchment output" ;
    char rivers(basins, lenstr) ;
        rivers:long_name = "Name of the river where the station is positioned" ;
    float upstream(basins) ;
        upstream:long_name = "Upstream area of the catchment" ;
        upstream:units = "km^2" ;
    float Localisation(basins, loc) ;
        Localisation:long_name = "Position of each catchment: (Lon, Lat)" ;
        Localisation:units = "degrees_east, degrees_north" ;
    float DisObs(years, basins) ;
        DisObs:long_name = "Discharge observation at the outlet of the catchment" ;
        DisObs:units = "m3/s" ;
    float E_ref(years, basins) ;
        E_ref:long_name = "Modeled average annual evaporation with forcing ref" ;
        E_ref:units = "m3/s" ;
    float P_ref(years, basins) ;
        P_ref:long_name = "Average annual precipitation for forcing ref" ;
        P_ref:units = "m3/s" ;
    float PET_ref(years, basins) ;
        PET_ref:long_name = "Modeled average annual potential evaporation with forcing ref" ;
        PET_ref:units = "m3/s" ;
    float DisMod_ref(years, basins) ;
        DisMod_ref:long_name = "Modeled Discharge with forcing ref" ;
        DisMod_ref:units = "m3/s" ;
    float E_f2000(years, basins) ;
        E_f2000:long_name = "Modeled average annual evaporation with forcing f2000" ;
        E_f2000:units = "m3/s" ;
    float P_f2000(years, basins) ;
        P_f2000:long_name = "Average annual precipitation for forcing f2000" ;
        P_f2000:units = "m3/s" ;
    float PET_f2000(years, basins) ;
        PET_f2000:long_name = "Modeled average annual potential evaporation with forcing f2000" ;
        PET_f2000:units = "m3/s" ;
    float DisMod_f2000(years, basins) ;
        DisMod_f2000:long_name = "Modeled Discharge with forcing f2000" ;
        DisMod_f2000:units = "m3/s" ;
    float E_cstmean(years, basins) ;
        E_cstmean:long_name = "Modeled average annual evaporation with forcing cstmean" ;
        E_cstmean:units = "m3/s" ;
    float P_cstmean(years, basins) ;
        P_cstmean:long_name = "Average annual precipitation for forcing cstmean" ;
        P_cstmean:units = "m3/s" ;
    float PET_cstmean(years, basins) ;
        PET_cstmean:long_name = "Modeled average annual potential evaporation with forcing cstmean" ;
        PET_cstmean:units = "m3/s" ;
    float DisMod_cstmean(years, basins) ;
        DisMod_cstmean:long_name = "Modeled Discharge with forcing cstmean" ;
        DisMod_cstmean:units = "m3/s" ;
    float E_cstintravar(years, basins) ;
        E_cstintravar:long_name = "Modeled average annual evaporation with forcing cstintravar" ;
        E_cstintravar:units = "m3/s" ;
    float P_cstintravar(years, basins) ;
        P_cstintravar:long_name = "Average annual precipitation for forcing cstintravar" ;
        P_cstintravar:units = "m3/s" ;
    float PET_cstintravar(years, basins) ;
        PET_cstintravar:long_name = "Modeled average annual potential evaporation with forcing cstintravar" ;
        PET_cstintravar:units = "m3/s" ;
    float DisMod_cstintravar(years, basins) ;
        DisMod_cstintravar:long_name = "Modeled Discharge with forcing cstintravar" ;
        DisMod_cstintravar:units = "m3/s" ;

// global attributes:
        :author = "Julie Collignan, julie.collignan@lmd.ipsl.fr" ;
        :model = "ORCHIDEE, IPSL, https://orchidee.ipsl.fr/" ;
        :source_stations1 = "Global Runoff Data Centre (GRDC), https://www.bafg.de/GRDC/EN/02_srvcs/21_tmsrs/riverdischarge_node.html" ;
        :source_stations2 = "Ministere de lenergie (February 2021), https://www.hydro.eaufrance.fr/" ;
        :source_stations3 = "Geoportal of Spain Ministerio (Ministerio de Agricultura, pesca y alimentacion, Ministerio para la transicion ecologica y el reto demografico, 2020" ;
                :atmospheric_dataset = "GSWP3, Hyungjun, K. (2017), doi: 10.20783/DIAS.501" ;
        :date = "28/07/2023";
}
```