See this post for a nice example how one can display the level of confidence in the data presented for a mapping unit on a map. The SoilWeb provides the distance from the nearest map unit polygon boundary. It gives the user a little more information that can be used to judge a relative degree of confidence in the returned soils data; Continue reading
In an earlier post I wrote how I created a mash-up map with MapTiler. There is an option in MapTiler to set transparency for a color, but this didn’t work for me at the time. I therefore created a small script to convert the background color to transparent and to process all PNG tiles generated by MapTiler using the PNGNQ utility.
I am working on a new online map and this time setting the background color to transparent in MapTiler works like a charm Continue reading
Ever wanted to create an open source web map but not sure where to start? The short tutorial ‘Blueprint for Creating an Open Source Web Map‘ by Michelle Ballinger might be just what you are looking for. This tutorial “takes the user through the steps of creating new data, modifying existing data to the map’s specifications, creating style layer descriptors, writing basic HTML, and posting to the Internet”. These steps are done in respectively QGIS, UDig, any text editor and GeoServer. Continue reading
For a project a few years ago we created a vegetation map for central and southwest Kenya (see http://ecodiv.org/trapnell for more information). The map together with documentation was initially made available on CD-ROM. I also created an online map. Apart from the version mentioned in this post, I also created a version with MapTiler.
MapTiler requires a georeferences image file as input. To export the vegetation map from my GRASS GIS database to a georeferenced image, I used the r.out.tiff function.
r.out.tiff -t input=veg_ethiopia_pnv@vegetation output=vegethiopia.tif
The resulting file can be used in MapTiler to create map mashups for Google Earth, Google Maps or OpenLayer. MapTiler offers a wizard like interface which leads you step by step through the process. Continue reading
For a project a few years ago we created a vegetation map for central and southwest Kenya (see http://ecodiv.org/trapnell for more information). The map together with documentation was made available on CD-ROM. However, we wanted to publish the map online too. The original maps were in svg format, and turned out to be too slow for online publishing. Moreover, they could not be combined easily with other maps.
Although Google maps and other online mapping tools become more powerful, creating and analyzing maps is still typically done using a desktop GIS. I am for example using GRASS GIS and QGIS for my work. These are very powerful tools, but what if I want to get a more detailed overview of how a certain area looks like? Or if I want to find out the towns in a certain region, or verify the existence of a lake in another? Continue reading
To create more synergy between projects and research efforts of one or more organizations, it is essential to have a good overview of ongoing projects, including where those projects are being implemented. A good example is the The CGIAR (the consultative Group on International Agricultural Research). This is a strategic partnership of 15 international agricultural research centers, working in collaboration with many hundreds of government and civil society organizations as well as private businesses around the world. The centers have offices and projects all over the world, making it rather a challenge for the managers or scientists within these institutes, but also for the many donors financing their work, to keep a good overview of what is happening and where.