Suitability analysis for Jatropha curcas production in Ethiopia - a spatial modeling approach

Abstract

Background: Jatropha is an oil-bearing plant growing in tropical and subtropical regions of the world within 30°N and 35°S latitudes. It is considered as a potential solution to the prevailing shortage of fossil fuel and environmental challenges. However, in most parts of Africa including Ethiopia, traditional land allocation systems for biodiesel investment do not involve integration of multiple variables. This research tries to introduce the advantages of Geographical Information Systems (GIS) and Spatial Analytical Hierarchy Process (SAHP) to identify suitable areas for jatropha production in Ethiopia. Combination of these methods enables integration of different environmental data in a multi-criteria analysis. The study will provide basic information in the biodiesel investment, which has been susceptible to failure due to poor land allocation. The methods used in this study will also be available for similar endeavors in the future. Results: In general, although individual factor evaluations provided varying amounts of suitability, results of weighted overlay analysis for biophysical suitability evaluation using spatial modeling methods identified 15.07% (166,082 km2), 76.57% (844,040 km2) and 8.36% (92114 km2) of the land as highly suitable, moderately suitable and not suitable for jatropha production, respectively. Conclusion: The methods used in this study provided considerably reliable estimate of suitable sites for jatropha production in Ethiopia. In this study, the main limiting factors of jatropha production identified were elevation, climate (temperature and rainfall extremities) and water logging conditions. Suitable sites do not compete with existing land use systems ensuring that biodiesel production will not risk food security programs.