Ecology and Development Series No. 10, 2003 - ZEF

Conservation of the wild Coffea arabica populations in situEthiopian Mapping Agency. The district department of agriculture performed thedemarcation of undisturbed and managed forests in agreement with the members of the localcommunity. The forest areas currently managed for coffee production, and the farmlands andsettlement areas in the surroundings were assigned a value 0 and the undisturbed forest areaswere assigned a value 1. The forest area is surrounded by large areas of farmlands andsettlement. However, only part of farmlands and settlements closer to the forest falling withUTM coordinates of 793870-830490 m E and 923320-934340 m N, zone 36.6.2.5 Reserve zoning: the multi-criteria evaluation methodMulti-criteria evaluation (MCE) deals with the allocation of land to suit a specific objectivebased on a variety of attributes that the selected area should possess. The MCE methodmakes it possible to combine the information from different evaluation criteria and to form asingle index evaluation or map. The IDRISI GIS software has a special MCE module(Eastman 2001). In GIS, two procedures are commonly used for MCE: the Boolean overlayand the index overlay techniques (Jiang and Eastman 2000). In the Boolean overlay, allcriteria are assessed by thresholds of suitability to produce Boolean maps, which are thencombined by logical operators such as intersection (AND) and union (OR). The indexoverlay method uses continuous criteria, which are standardized to a common numeric range,and then combined by weights. There are two commonly used index overlay techniques:weighted linear combination (WLC) and order-weighted average (OWA). Since criteria varyin importance for decision-making, the importance of the criteria used in the evaluation isachieved by assigning a weight to each criterion.106