Contours of Greece from SRTM Data

This post for users of GIS.

You should really take the time to learn how to create contour lines automatically so that you can produce topographic maps at different elevation intervals for whatever region you are researching.

But, for those without access to extensions like spatial analyst that enable the conversion, or the time to mess with this, I will offer the following shape file data sets for 1) the Peloponnese and part of central Greece, and 2) the Corinthia.

The two images below display the extent of the contours that I’m linking to here.

The first shows  the extent of contour coverage for southern and central Greece. At the end of this post, you’ll see links for 20 meter and 100 meter contours for this broad area.

Peloponnese_SRTM_100m

The second image shows the modern regional unit of the Corinthia (and western Attica), which includes the ancient territories of Corinth, Sikyon, Tenea, and Megara. I will link to files containing 20 meter contours for this area.

Corinthia_20m_SRTM

I generated these shape files from SRTM data through a simple conversion via the “Contour” tool in the ArcGIS extension Spatial Analyst — see my previous post about the process. (SRTM data refers to Shuttle Radar Topography Mission that marks a particular research endeavor by NASA to make high-resolution topographic data globally available.)

The image below shows the SRTM DEM that was used to generate the contours.

SRTM_41_05

I downloaded the SRTM file shown above (“SRTM_41_05”) from the CGIAR Consortium for Spatial Information website, which describes the data sets in the following way:

“The CGIAR-CSI GeoPortal is able to provide SRTM 90m Digital Elevation Data for the entire world. The SRTM digital elevation data, produced by NASA originally, is a major breakthrough in digital mapping of the world, and provides a major advance in the accessibility of high quality elevation data for large portions of the tropics and other areas of the developing world. The SRTM digital elevation data provided on this site has been processed to fill data voids, and to facilitate it’s ease of use by a wide group of potential users. This data is provided in an effort to promote the use of geospatial science and applications for sustainable development and resource conservation in the developing world. Digital elevation models (DEM) for the entire globe, covering all of the countries of the world, are available for download on this site. The SRTM 90m DEM’s have a resolution of 90m at the equator, and are provided in mosaiced 5 deg x 5 deg tiles for easy download and use. All are produced from a seamless dataset to allow easy mosaicing……

Dr. Andy Jarvis and Edward Guevara of the CIAT Agroecosystems Resilience project, Dr. Hannes Isaak Reuter (JRC-IES-LMNH) and Dr. Andy Nelson (JRC-IES-GEM) have further processed the original DEMs to fill in these no-data voids. This involved the production of vector contours and points, and the re-interpolation of these derived contours back into a raster DEM. These interpolated DEM values are then used to fill in the original no-data holes within the SRTM data. These processes were implemented using Arc/Info and an AML script. The DEM files have been mosaiced into a seamless near-global coverage (up to 60 degrees north and south), and are available for download as 5 degree x 5 degree tiles, in geographic coordinate system – WGS84 datum.”

According to their disclaimer about liability, distribution, and acknowledgement/citation, these contours are freely available for (non-commercial) educational and research purposes, but users should cite the data source for publications and reports:

“DISTRIBUTION

Users are  prohibited from  any commercial,  non-free resale,  or redistribution without explicit written permission from CIAT. Users should acknowledge CIAT  as the source used  in the creation  of any reports,  publications, new data  sets, derived products, or services resulting from the use of this data set. CIAT also request  reprints of  any publications  and notification  of any  redistributing efforts. For commercial  access to  the data,  send requests  to Andy Jarvis.

ACKNOWLEDGMENT AND CITATION

We kindly ask  any users to  cite this data  in any published  material produced using this data,  and if possible  link web pages  to the CIAT-CSI  SRTM website (http://srtm.csi.cgiar.org).

Citations should be made as follows: Jarvis A., H.I. Reuter, A.  Nelson, E. Guevara, 2008, Hole-filled  seamless SRTM data V4, International  Centre for Tropical  Agriculture (CIAT), available  from
http://srtm.csi.cgiar.org.”

DATA SETS

Finally, the data sets. The following zipped folders each contain 7 individual files that are needed as a package for recognition by ArcGIS. Right click on the file and save to your computer. I will post some ‘permanent’ version of the notes above to this page in the website.

Enjoy, but please do remember to cite the CIAT-CSI  SRTM website.

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