Combining multi-criteria decision analysis with GIS approaches for decentralized organic wastes composting plants site selection in Tiassalé, Southern Côte d’Ivoire

Abstract

In recent years, decentralized composting appeared as one of the most appropriate treatment options for organic waste valorization in low- and middle-income countries. In Cote d’Ivoire, a pilot project has proved the feasibility of organic municipal solid waste composting for the city of Tiassalé. However, numerous issues still need to be addressed for the establishment of a sustainable decentralized composting system in this city. One of the key issues is site selection. Until now, there is no clear model for such plant site selection. In this study, multi-criteria decision analysis (MCDA) and geographical information system (GIS) approaches were combined to develop an appropriate model for selecting decentralized composting sites in the city of Tiassalé. The methodology used involved two different and complementary phases. First, MCDA and GIS techniques were used to identify the most suitable site areas. Seven criteria clustered in three main factors (environmental, social and economic), and five constraints were considered in the analysis process. Second, five sites were selected within the most suitable areas after a basic field visit and ranked using the Analytic Hierarchy Process. The results showed that the most suitable spaces for decentralized composting plant siting represent only 2.6% of the study area. The investigation yielded on the selection of the two best options for decentralized composting plant siting for the city of Tiassalé. This study proved that the combination of MCDA and GIS is a practical and efficient method to identify suitable sites for decentralized composting plants.

Decentralized Composting Analysis Model—The Qualitative Analysis Path

“…The most discussed conflicts in the literature for the various types of composting systems are [25][26][27][28][29]:…”

“…The composting site should fulfil certain requirements and criteria in order to minimize potential conflicts. It should be accessible, be located near water and energy infrastructures, and include a "sufficient" buffer zone, which can help in cases of malfunction or dysfunction of the composting system [25][26][27][28][29].…”

“…It, therefore, appears as a "Go or No-Go" criterion, meaning that if such an area is not available, the whole project cannot be implemented. This area should be selected according to specific regulations and the conditions of the local environment [25][26][27][28][29]. If the former do not exist, then they should be adapted from other locations, locally or around the world, with successful composting projects.…”

Decentralized Composting Analysis Model — The Qualitative Analysis Path

“…The most discussed conflicts in the literature for the various types of composting systems are [21][22][23][24][25]: 1. Site selection for DC system 2.…”

“…The composting site should fulfil certain requirements and criteria in order to minimize potential conflicts. It should be accessible, be located near water and energy infrastructures, and include a "sufficient" buffer zone, which can help in cases of malfunction/dysfunction of the composting system [21][22][23][24][25].…”