Why Geo e-Links?
Geo e-Links Africa information resources
File sizes and downloading time

What is Geo e-Links Africa?

Geo e-Links is a unique online information resource for sustainable rural development in Africa that employs maps to display locations where experiences or research about sustainable development have been documented. From the map the user can link to the documents in the DEVECOL digital library or on the World Wide Web. To find and access documents, start a map search, zoom in on a region until a label appears at the document site. Then click on the site.

The maps also serve as the basis for searches of documented experiences according to general environmental characteristics in the area where an experience has been recorded. This search is done using the query form. Search results link to the maps as well as to the documents.

• The existence, pattern, and proximity of places with documented development experiences, research and the like can be quickly appreciated.
  
  
• Document briefs, full text and photographs can be accessed directly from Geo e-Links map views.
  
  
• The maps simultaneously display site-specific documentation available from diverse institutions.
  
  
• The general environmental characteristics of documented experiences are revealed by the maps and are used to query the document database.The continental scope of the maps offers a comparable basis for understanding the general terrain, soil, and climate environments of experiences throughout Africa.
  

The site-specific context of rural development that is ecologically and socially sustainable presents unique challenges to knowledge management and the extension of successful innovations. The possibility of "re-inventing square wheels", i.e. promoting unworkable solutions, is ever present. What works well in one place may fail in another. Equally problematic is the possibility of not being able to capitalize on successful experiences in other, perhaps distant, places having comparable environments and demographic characteristics. Finding documented experiences in comparable sites is frustrated by several obstacles which make the documents either invisible to electronic searches or difficult to assess as to their utility.

In a document with numerous case studies, the bibliographic record usually will not cite them. If cited by title, a case study may refer to localities unfamiliar to the searcher, such as villages or local administrative districts which cannot be found on available maps. Determining if a documented experience is in an environment that is generally comparable to the one of interest to the searcher may be difficult. Key words corresponding to universally applicable ecological descriptors are not used in document database records, while full text searches may find none in the document itself. See "The Use of GIS in Information Management in Africa" in Background papers for a more detailed elaboration of these points.

The DEVECOL information system overcomes these obstacles by geo-referencing individual studies and displaying them on base maps as well as maps of soils and agro-climate that employ continent-wide classifications.

A query form search mode complements the map searches. It allows the user to seek documents according to general ecological descriptors, as well as country, subject matter, author,and other parameters.

Geo e-Links Africa information resources

These comprise base maps, thematic maps, and a growing, geo-referenced database of case studies that are accessed from this site's digital library or via hyperlinks from other WWW sites, including the U.N. Food and Agriculture Organization, the Overseas Development Institute, FRAME, the Regional Land Management Unit (RELMA, now a part of ICRAF), and LEISA(Magazine for low external input and sustainable agriculture).

Site-specific case studies, evaluations, field survey or research reports, and other documents of particular interest to sustainable development and recovery efforts are accessed from the Geo e-Links maps. Case study topics include parks,wildlife, and biodiversity conservation; forest management and forestation, sustainable agriculture, agroforestry and agroecosystem management; soil and water conservation, and management of grasslands or other grazing resources. The library documents are linked to the map interface via the geo-referenced database of the documents. The library documents and those on other sites are accessed either from the query form or directly from the map displays.

Base maps at several levels of detail are displayed: all Sub-Saharan Africa, regions of Africa, and sub-regions or areas within countries.. The latter show the most detail; the nominal scale of precision is 1:1 million however shorelines and rivers are accurate to approximately 1:500,000.

Base maps are developed from several data sources:

Africa Data Sampler. World Resources Institute. Includes the original(1994) version of the Digital Chart of the World (for Africa), parks and protected area datasets from the World Conservation Monitoring Centre, and administrative and demographic datasets from the National Center for Geographic Information and Analysis, U. of California, Santa Barbara.

Continental roads and rivers datasets for Africa were provided by the USGS's Eros Data Center.

Named places (gazetteer) datasets for African countries are from the National Imagery and Mapping Agency (NIMA) web site. These datasets supercede the named places data in the early versions of the Digial Chart of the World.

Climate and soil maps were developed from FAO datasets: Digitized Maps of the Major Climatic Divisions and Lengths of Growing Period Zones for the Developing World(Release 1.1); Digital Soil Map of the World, and Soil and Terrain Database for northeastern Africa. For portions of East and southern Africa, 5 kilometer resolution rainfall and P/PET maps were developed with data from the African Country Almanac Series, version 3.0, produced for USAID's Africa Bureau by the Texas A&M Blackland Research Extension Center in 2001. Map legends include links to text wtih soil descriptions for the FAO soil maps and text explaining the length of growing period.

File sizes and downloading time

Documents

Documents are in Adobe portable document file(.pdf) format or html format (if accessed online). Adobe .pdf files of documents are mostly less than 100 KB in size, although those with photographs as part of the document are larger - up to 400 KB. Only a few documents exceed 400 KB. The smaller documents will download in several seconds.

If you do not have Adobe Acrobat Reader and you wish to obtain this free software, click here.

Map views

A series of static map views at different scales are accessed from the initial map of the African continent. This solution has been chosen to accomodate users in Africa and elsewhere who do not have the high speed connections that are needed to take advantage of Interactive maps on the Internet.

The map images will take a few seconds to "build", i.e. download. Map file sizes have been minimized by using the portable network graphic format (.png). Most map images are in the 50 KB to 60 KB range. A few are larger; none exceed 100 KB.

Download times will vary according to your modem speed and usually will be from 5 to 10 seconds with a 56 Kbs modem. Please be patient. After the initial download, the map views will appear more quickly because they will have been saved (cached) on your hard drive (C:/Windows/TemporaryInternetFiles/ContentIE5 -- if you are using Internet Explorer). If you delete your temporary Internet files you will lose these map downloads, unless you exclude them from deletion.

Photographs

For some experiences photographs can be accessed from the document brief window. They are generally larger files than the map image files and will take more time to download than the map images. For slower modems(i.e 28.8 KB bps) display of the foto will be delayed by 20 or more seconds while the download is in progress.