Exploring the use of AHP in land suitability analysis for quality apple growing in southwestern Uganda.

Abstract

Apple growing is one of the go to options that have been embraced by the Ugandan government in a bid to eradicate poverty among its people due to its high profitability potential. Apple growing is being practised in South Western Uganda due to its favourable climate conditions and many farmers in the area have taken up the venture. However, the inexplicit research carried out by earlier researchers (only considered soil, climate and topography) to determine whether South Western Uganda was suitable for apple growing has availed limited information about suitability levels of the area which is being used by apple farmers to expand their orchards and in return realize fewer returns. This study, therefore, aimed to carry out explicit research in land suitability analysis for quality apple growing in South Western Uganda while taking into consideration different factors such as soil, rainfall, temperature, aspect, altitude, slope, distance from roads, rivers, lakes, protected areas and built-up areas so as to provide more information about suitability levels for quality apple growing in South Western Uganda. The Analytical Hierarchy Process (AHP) method was used to rank the various suitability factors and the resulting weights were used to construct the suitability map while making use of the weighted sum overlay tool in ArcGIS 10.5. The different suitability levels that’s to say; most suitable, suitable, less suitable and not suitable were identified from the suitability map. Analysis of the suitability map showed that most suitable areas (222177.38 ha) covered 5.5%, suitable areas (420227.28 ha) covered 10.4%, less suitable areas (1142980.61 ha) covered 28.2% and areas not suitable covered (2270656.99 ha) covered 55.9 of the total land in South Western Uganda. The results showed that potential areas for quality apple growing cover an area of 1785385.27 ha of which 12% were highly suitable, 24% were moderately suitable (suitable) and 64% were less suitable (marginally suitable) for quality apple growing in South Western Uganda. Furthermore, the ROC curve method was used to check the effectiveness of the results by computing Area Under Curve (AUC) that showed a satisfactory prediction of suitable areas of 63%. This research recommends that the AHP method be used for land suitability analysis studies since it saves time and it’s not costly. Lastly, the information provided by the suitability map obtained from the study could be used by government (or farmers themselves) to advise apple farmers to practice the already learnt apple management skills in areas suitable for quality apple growing.