Example-Data.md

+
+Here we describe how the example data sets were created. All example data
+can be downloaded from our server
+[https://www.wsl.ch/lud/TMWrapper](https://www.wsl.ch/lud/TMWrapper) or by
+means of the R functions in the tmwrapper software.
+
+
+## Climate data
+
+The forest-landscape model
+[TreeMig](https://doi.org/10.1016/j.ecolmodel.2005.11.046) needs climate
+data in high resolution as input.
+
+The [CH2018 Climate Scenarios for
+Switzerland](https://www.nccs.admin.ch/nccs/de/home/klimawandel-und-auswirkungen/schweizer-klimaszenarien.html)[1][2]
+provide daily time series 
+
+- at [individual Swiss
+stations](https://www.nccs.admin.ch/dam/nccs/de/dokumente/website/klima/stations_CH2018_meta.csv.download.csv/stations_CH2018_meta.csv)
+and 
+
+- on a regular 2km grid.
+
+Both data sets [(DAILY-LOCAL and
+DAILY-GRIDDED)](https://www.nccs.admin.ch/dam/nccs/de/dokumente/website/klima/CH2018_documentation_localized_v1.2.pdf.download.pdf/CH2018_documentation_localized_v1.2.pdf)[3]
+include data of 68 [EURO-CORDEX](https://www.euro-cordex.net) simulations for the scenarios RCP2.6, RCP4.5
+and RCP8.5. All data are available under the Creative Commons license
+[CC BY 4.0](https://creativecommons.org/licenses/by/4.0).
+
+Since a higher resolution of 200m was required for an example data set, we used a 200m digital 
+elevation model (see [below](#digital-elevation-model)) and the 
+interpolation software *Daymet* by [Thornton, et al. (1997)](https://doi.org/10.1016/S0022-1694(96)03128-9)[4]
+to interpolate the DAILY-LOCAL data from the
+[individual Swiss stations](https://www.nccs.admin.ch/dam/nccs/de/dokumente/website/klima/stations_CH2018_meta.csv.download.csv/stations_CH2018_meta.csv)
+of the simulation CLMCOM\_CCLM4\_MPIESM\_EUR11\_RCP85.
+
+The new 200m daily gridded data were converted to NetCDF format and 
+subsequently aggregated to monthly means (temperatures) and 
+sums (precipitation) using the Climate Data Operators [CDO](https://code.mpimet.mpg.de/projects/cdo).
+
+
+## Digital elevation model
+
+
+The digital elevation model [DHM25/200](https://www.swisstopo.admin.ch/de/geodata/height/dhm25200.html)
+by the [Federal Office of Topography 
+swisstopo](https://www.swisstopo.admin.ch/) was first reprojected to the current 
+*Official Swiss reference system* 
+[CH1903+](https://www.swisstopo.admin.ch/en/knowledge-facts/surveying-geodesy/reference-systems/switzerland.html).
+Elevations were rounded to whole numbers. The resulting DEM was then cut
+out along a 1km buffer outside the Swiss border and exported to Arc/Info
+ASCII Grid format.
+
+
+## References
+
+[1] CH2018 (2018), CH2018 – Climate Scenarios for Switzerland, Technical
+    Report, National Centre for Climate Services, Zurich, 271 pp.
+    ISBN: 978-3-9525031-4-0
+
+[2] CH2018 Project Team (2018): CH2018 - Climate Scenarios for Switzerland.
+    National Centre for Climate Services.
+    doi: 10.18751/Climate/Scenarios/CH2018/1.0
+
+[3] Kotlarski S., Rajczak J. (2018): CH2018 - Climate Scenarios for Switzerland,
+    Documentation of the localized CH2018 datasets - Transient daily time
+    series at the local scale: DAILY-LOCAL, DAILY-GRIDDED.
+
+[4] Thornton, P.E., Running, S.W., White, M.A. (1997): Generating surfaces
+    of daily meteorological variables over large regions of complex
+    terrain. J. Hydrol. 190: 214-251. https://doi.org/10.1016/S0022-1694(96)03128-9