GIS Links Food Security and Demining Programmes
Summary of published paper1
According to a recent article in Humanitarian Exchange, geographic information systems (GIS) are playing an increasingly important role in food security and demining programmes. GIS are computer-generated maps, built up with layers of information. The key components are land use, infrastructure, and topography, on top of which information on other features such as population movements, settlements patterns and accessibility, may also be layered.
Mining poses serious problems in more than 65 countries. In Afghanistan, for instance, an estimated 25% of agricultural land and 66% of grazing land is mined. Identifying areas of fields that can be clearly marked, fenced off or cleared is an important use of GIS mapping, especially when linked to land reclamation activities. High resolution satellite imagery from the internet (IKONOS, IRS)2 provides basic topological and statistical data for an initial framework for analysis. Key visual clues from satellite images include linear ploughshare patterns across patches of terrain, trenches, artificial embankments fencing (especially along borders), evidence of military activity and seasonal variations in land use. However, satellite imagery and remote sensing tend to overestimate the extent of mined areas. Alternative survey methods must then be used to refine initial assessments. For studies on a smaller or very local scale, photos from aerial surveys are an alternative source. New technologies including radar and 3-D imaging for local surveying are being tested and refined. Ground surveys around the perimeter of the suspected minefield can then clarify or correct the maps compiled.
When addressing food security in regions where mines are a risk factor, a combination of data can be digitised and compared, to coordinate demining programmes with security plans. If land use maps were applied to demining, the darkly shaded patches would indicate minefield areas of greater mine density. The lighter shaded areas would therefore indicate the first choice for land clearance, if the requirement were ease and rapidity of response. If other data - for instance, settlements, water sources and roads - were added, the areas of choice would gradually narrow to those locations where clearing mines would have the greatest benefit in terms of access to productive land.
The multiplicity of auxiliary data sources and the number of agencies working in the field make coordination a key obstacle to the effective use of GIS in food security and demining. Experience in Mozambique and Afghanistan has indicated that much information derived from local surveys is incomplete, inaccurate and not based on compatible standards. In conflict regions, it is also difficult to gain uniform access for thorough and timely mapping.
The article concludes that with adequate data input, GIS can reveal relationships not easily discerned through other survey methods, such as the link between the probability of crop failure and a community's risk of food shortage. Food security and demining are both linked to issues of land use, and are therefore ideal sectors for the use of geographical information systems. Identifying land suitable for cultivation is one of the principal benefits of applying GIS in demining strategies.
1Abott, K (2003). Geographic information systems in food security and demining programmes. Humanitarian Exchange, no 24, July 2003 pp 131-133
Taken from Field Exchange Issue 21, March 2004