GIS and remote sensing coupled with analytical hierarchy process (AHP) for the selection of appropriate sites for landfills: a case study in the province of Ouarzazate, Morocco

Abstract

AbstractThe province of Ouarzazate has a population of 10,744 and is divided into 17 communes (15 rural communes and 2 urban communes), the majority of which have a population of less than 2000 people. Currently, more than 42% of the total population does not have access to a controlled landfill that meets all the socio-environmental criteria defined by Law 28-00 and its implementing regulations. The most typical landfills are located in small villages that resemble illegal dumps or dark areas close to the inhabitants. Moreover, in 2009, a controlled landfill was established near the city of Ouarzazate. Over time, urban extensions tend to move towards the site of the landfill following the development plans of the city, which influences the environmental life and health of the new population. Indeed, this landfill is considered to be located in the wrong place according to the results of our study; it does not meet all the main socio-environmental criteria. For these reasons, this study was conducted to identify appropriate landfill sites and waste transfer centers using geographic information systems (GIS) and remote sensing coupled with multi-criteria evaluation techniques such as AHP. Eleven criteria were selected, including distance to protected areas, wind direction, subsurface geology, lineament density, distance to surface water (river systems and dams), soil quality, distance to roads, elevation, and slope. The rasters of all the criteria were prepared, processed, and overlaid in the GIS environment by assigning each parameter its weight according to its importance. In the field, five sites have been provisionally selected, but only sites D and B have been given higher priority because of their geographical location, large surface area, geological imperviousness, zero risks, better soil quality, distance from any protection zone, any water point or hydrographic network, and their accessibility by provincial roads. These sites are located very close to the province’s waste hubs, which helps reduce the cost of transporting waste to the new landfill.