Compost Plant Site Selection for Food Waste Using GIS Based Multicriteria Analysis

Marketplace waste collection is one of the crucial services provided by the district municipalities in Turkey. A significant amount of food waste is periodically collected from marketplaces. However, an important opportunity for recycling and mitigation climate change is missed because these waste are sent to landfills. Composting, one of the waste management technologies applied to organic waste to reduce greenhouse gas emissions and produce compost, is often preferred for the management of marketplace waste. This study aims to determine suitable locations for compost facilities to manage marketplace waste with the help of GIS considering economic, environmental, and topographic factors in Izmir, Turkey. There are 199 marketplaces in Izmir and each has at least one market a week. Each marketplace was weighted by means of population served by using location-allocation analysis since the amount of waste collected from the marketplaces is not known. First, an exclusion analysis was performed to remove limited use areas. Then, a preference analysis was performed. Factors affecting plant site selection process for composting marketplace waste, including marketplace locations and weights, were determined. Since all factors do not have equal importance, the analytical hierarchy process was used to determine weights for each factor based on their influence. The study area was spatially evaluated for each preference factor and a suitability map was created for each factor. Finally, a high-resolution final suitability map was obtained by combining each factor’s suitability map along with their weights. Areas with a suitability index greater than 80% have been defined as suitable areas for compost facility installation. The results indicate that there are 323 potential locations suitable for compost facilities in Izmir.