Objective: To introduce the RSAGA package that can be used to execute SAGA GIS geoprocessing tools (over 450 functions for geodata analysis); to demonstrate how processing of large GIS data can be implemented by combining SAGA GIS processes (SAGA cmd) and R code.
General description: R + SAGA GIS are a powefull combo of software packages that allow geographical and statistical computing with large data (SAGA GIS is programmed in C++ and is optimized for processing GIS raster and vector data). The link between SAGA GIS and R is possible due to the RSAGA package. Participants will be introduced to both software environments and several practicial tips will be provided on how to program using RSAGA package and how to exchange data from SAGA GIS to R. Note: The argument names in all new versions of SAGA GIS (>2.1) will most likely be kept constant so that programming with RSAGA will not have to be constantly updated as the new versions of the software arrive (read more).
Required back-ground knowledge: Basic understanding of GIS operations and data types.
Software / R packages required: SAGA GIS v2.1, FWTools; R packages: RSAGA, rgdal (NOTE: SAGA GIS is not yet available for MacOS!)
Daily programme (Tuesday 17 June):
- 9.00 - 10.30: Software installation and first steps in SAGA GIS (using the Ebergotzen case study)
- 10.30 - 11.00: Coffee break
- 11.00 - 12.30: Connecting R and SAGA GIS using RSAGA package / overview of SAGA GIS modules
- 12.30 - 13.30: Lunch
- 13.30 - 15.00: Advanced exercise - error propagation using R+SAGA GIS
- 15.30 - 17.00: Advanced exercise - loading your own data to SAGA GIS (please bring your data sets with you!)
- Brenning, A., 2008. Statistical geocomputing combining R and SAGA: The example of landslide susceptibility analysis with generalized additive models. In: J. Boehner, T. Blaschke & L. Montanarella (eds.), SAGA - Seconds Out (= Hamburger Beitraege zur Physischen Geographie und Landschaftsoekologie (19), 23-32.
- Brenning, A. 2014. RSAGA: SAGA Geoprocessing and Terrain Analysis in R. CRAN package.
- Conrad, O. 2007. SAGA - Entwurf, Funktionsumfang und Anwendung eines Systems für Automatisierte Geowissenschaftliche Analysen. electronic doctoral dissertation, University of Göttingen.
- Hengl, T., Heuvelink, G. B. M., van Loon, E. E., 2010. On the uncertainty of stream networks derived from elevation data: the error propagation approach. Hydrology and Earth System Sciences, 14:1153-1165.