May 302012

Hillshades are made by processing georeferenced digital elevation models. The process places a virtual light source above an elevation model and calculates which areas are lightened up and which fall in the shadow. Light characteristics, vertical/geographical source will be determinant for the hillshade.

Some years ago I prepared a hillshade model for Tanzania. It was fun and before I knew it I had prepared elevation models for seven more countries.

This article points to a file gallery where the files are available for download. Continue reading »

Jan 062012

For anyone interested in trying out QGIS, I’ve put together a folder with a complete QGIS project and a selection of raster and vector data for you to explore.

The archive includes:

  • Some of the usual border and protected area data we’ve been sharing on this site for years (some of which seriously need updating) – lakes, regions, protected areas;
  • December 2011 OpenStreetMap road data for the whole country, with a rule-based rendering system that renders various road levels as you zoom in; it matches the OSM default web rendering as much as possible.
  • GTOPO low-resolution DEM for the country (as a JPEG) with elevation colours customised in the layer.

Download QGIS if you haven’t already (, open the tz_elevations.qgs file, and play!

[wpfilebase tag=file id=1 /]

Jul 042010

The World Database on Protected Areas (WDPA) is the most comprehensive global spatial dataset on marine and terrestrial protected areas available. The 2010 version of the data were published earlier this year.
Since 1981 UNEP-WCMC has ever since 1981 been compiling this information and making it available to the global community. This has been done through their Protected Areas Programme. The WDPA is a joint project of UNEP and IUCN, produced by UNEP-WCMC and the IUCN World Commission on Protected Areas working with governments and collaborating NGOs.

They describe their databases this way:

“The World Database on Protected Areas is a foundation dataset for conservation decision making. It contains crucial information from national governments, non-governmental organizations, academic institutions, international biodiversity convention secretariats and many others. It is used for ecological gap analysis, environmental impact analysis and is increasingly used for private sector decision-making.”

For their 2010 publication they specifically note the following:

We are aware that some of the protected areas for Tanzania in this data set are not always 100% accurate. It is however the only data set providing updated continental level information on a regular basis. As such it is a good starting point for research. For management we would advice the user to contact the ministry (MNRT) for the most updated information.

The undersigned and colleagues are planing to publish a PDF map for free distribution based on this map quite soon. Stay tuned – and in the meantime visit WDPA:

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