Anna's Travel Maps® - acquire maps using PayPal's shopping cart. Full-colour Gambia map showing all major roads and over 600 town and village names, points of interest including accommodation, petrol stops, public facilities, and cultural and historical sites. Also includes detailed city plans of Kanifing Municipal Council and the City of Banjul.

GIS Data

Short answer: GIS is a kind of computer program that you can use to make and analyze maps.

Long answer: A geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on Earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps. These abilities distinguish GIS from other information systems and make it valuable to a wide range of public and private enterprises for explaining events, predicting outcomes, and planning strategies.

On this web site you can download GIS data for the administrative boundaries (country, region, and district) of The Gambia. This data was obtained for free off the internet from the Africa Data Dissemination Service. See below for details on how to download this data.

Also available on this web page are GIS coverages for landuse and vegetation data. For example these will tell you which areas of The Gambia are wetlands, forested, used for rice agriculture, etc. These coverages have been graciously offered by Geir Tyldum. See below for details on how to download this information.

For other sources you can also read a guide to resources on geography, mapping, and imaging in Africa.

I hope to eventually add data for roads, villages, landmarks, etc, but I am having problems finding this data in an electronic format. If you know where to get GIS coverages for this type of information, please send me a note.

You need a special program to look at GIS data. There are several GIS programs available, but ArcView, from Environmental Research Systems Institute (ESRI), is probably the most common one. ArcView costs a lot of money, but ESRI recently made a miniature version of ArcView, called ArcExplorer, available online for free. Unfortunately, ArcExplorer only works on Windows 95 or Windows NT. If you have Windows 3.x, then you can not use ArcExplorer.

If you have Windows 3.x, you can download and install ArcView 1.0, an older version of ArcView, which is also free from ESRI's web site. Unfortunately however, this won't help you view the GIS data available on this web site because ArcView 1.0 can not open Shapefiles. In the not too distant future I hope to convert the Gambian GIS data to a format that ArcView 1.0 can open.

If you have a Mac, then I don't know of any free GIS viewer that would allow you to look at GIS data. However you can buy versions of ArcView for the Mac.

You can download ArcExplorer for Windows 95/NT from ESRI's web site.
Once you download the ArcExplorer installation file to your hard drive and install it, you can open and view the Gambia data files.

Once you have ArcExplorer installed and have downloaded the GIS data from this web page, you can use ArcExplorer to view the information in a variety of ways. You can choose to look at district boundaries, regional boundaries, or just the national borders. You can change how the program displays the maps, such as the colors. You can click on a region or district with the information tool to see characteristics such as its name and area. You can zoom in or out of an area, and copy views to the clipboard so that you can paste them into other programs. This can be very useful if you are writing a report or presentation. You can do all of the above with the landuse and vegetation data as well.

Things you can not do with ArcExplorer include adding new data, such as roads or villages. You are also limited in the types of analysis you can do because there are not many attributes associated with an area other than its name. You could do things like select all the districts with an area greater than x, or that are in URD, and make them appear different. You could show all the areas of region 3 that are riparian woodlands. You can put your own labels on the districts, regions, or vegetation areas. Hopefully in the future we'll have village locations and road information as well, and maybe even census data.
 

Click on the thumbnail image to the left to see an example of GIS data in ArcExplorer.

Administrative boundaries
The administrative boundaries data is available as a self-extracting compressed archive gam_admn.exe (257 Kb). After you download the file, run it (by double-clicking on it in Explorer) to extract the files. (Note this will only work for an IBM compatible computer. If you have a Mac, then you need to use a utility like the shareware program ZipIt to manually unzip the files from gam_admn.exe. Email me for details.) Once you have downloaded and decompressed the file, you can open the coverages with ArcExplorer.

Remember, unless you have a GIS viewer, such as ArcExplorer, that can open GIS data in shapefile format, you won't be able to use this GIS data.

Land cover
Many thanks to Geir Tyldum for providing this data
Because the land cover GIS files are fairly large, they have been divided into four regions which collectively represent the entire country of The Gambia. These coverages are available as four self-extracting compressed archives which can be downloaded below.
 

gam_lu1.exe 517 Kb	gam_lu2.exe 723 Kb	gam_lu3.exe 576 Kb	gam_lu4.exe 622 Kb
Or download a landcover coverage for the entire country in ArcInfo export format (E00). gamap_all.zip (2 Mb, 11 Mb when expanded)

Note: these covers are in the UTM coordinate system, zone 28. Units are in meters.

After you download a file, run it (by double-clicking on it in Explorer) to extract the files. (Note this will only work for an IBM compatible computer. If you have a Mac, then you need to use a utility like the shareware program ZipIt to manually unzip the files. Email me for details.) Once you have downloaded and decompressed the files, you can open them with ArcExplorer. See also the notes for the land cover and vegetation numerical codes.

As menioned above, in the future I hope to make this GIS data available in a format that you can open with ArcView 1 for Windows 3.x, a free program available from http://www.esri.com.

But until that happens, you can either use another GIS viewer (if you have one) that can open Shapefiles, or you can settle for some downloadable Gambian map clipart available on this web site.