GIS-multi criteria assessment of land suitability and optimal sites allocation for large scale pineapple production in the Akwapim South District, Ghana

Abstract

Land suitability assessment, in the context of land use planning, is a bridging phase linking land resources assessment to any land use decision-making process. Like elsewhere, land use suitability assessment in Ghana is influenced by inherent conflicts and a complex network of socio-economic and ecological constraints that call for a flexible decision-making support tool able to incorporate multiple evaluation criteria, including the opinions of several stakeholders. In this paper, we report on a GIS-based multi-criteria approach to land suitability evaluation for pineapple production in the Akwapim South Municipality of Ghana. The crop is an important export earner, having contributed significantly to foreign exchange receipts of the country since the 1980s, although its cultivation has also increased land use conflicts and aggravated land degradation. The study relied on several decision support tools such as high spatially-resolved remotely sensed data, geographical information system (GIS) and multi-criteria decision analysis (MCDA), including analytical hierarchy process (AHP). The approach enabled decision makers to evaluate the relative priorities of locating sites for cultivation of the crop, based on a set of preferences, criteria and indicators. Weighted Linear Combination (WLC) techniques were used to integrate fuzzy suitability criteria maps of decision groups and a consistency ratio between criteria was calculated using the Saaty matrix cross-comparison technique. An iterative post-aggregation constraint was applied to identify potential sites as basis for delineating potential areas for pineapple cultivation. In the context of potentially high export market demands of the crop and its significant economic contribution to the local economy, this study is of national relevance. Moreover, the results in form of maps may also be used by agricultural managers as decision-support tools, for instance, to outline the most suitable land areas for subsidy support for increased pineapple production in the district.