INTEGRATED ANALYTICAL HIERARCHY PROCESS - GIS MODEL FOR LANDFILL SITING: A CASE STUDY FROM INDIA

摘要

Human activity, either domestic or industrial, produces waste materials to greater or lesser extent always. Each city produces tons of solid wastes daily from household, hospitals, industry, offices and market centers. By volume, municipal solid waste is by far the largest component of overall urban waste stream and includes a variety of potentially toxic substances making its disposal a problem. However, either due to resource crunch or inefficient infrastructure, not all of this waste gets collected and transported efficiently to final dumpsites leading to an improper management and disposal, resulting in serious impacts on health and problems to surrounding environment. The efficacy of solid waste disposal depends upon selection of proper site and there are several issues that have impact for site selection. Site selection is therefore one of the most critical areas of municipal planning involving a multi-disciplinary approach and a broad spectrum of considerations. As such, it is a multi-criteria decision-making process, a much-needed system for proper municipal solid waste management. This paper attempts to demonstrate the capabilities and utility of remote sensing and G1S technology for selection of suitable sites for waste disposal for Hyderabad City, India. The study illustrates the application of GIS techniques in the field of solid waste management, through the typical problem of preliminary disposal site selection, using a multi-criteria decision making technique called the Analytic Hierarchy Process (AHP) which provides a systematic approach for assessing and integrating the impacts of various factors, involving several levels of, dependent and independent, qualitative and quantitative information. Remote sensing images and Survey of India topomaps are used to extract information on wastelands and other land use features, geology, hydrogeomorphology, drainage, road network and slope of the area. The approach used in this project was firstly to exclude all areas where the development of a waste disposal site would not be permitted viz., close proximity to residential areas, airfields, mountainous areas, nature reserves, indigenous forests, geological faults, the coast, dams or rivers. Once these areas had been identified, the remaining areas were then rated according to the geological, hydrological, topographical and environmental characteristics. From the combination of these factors, favorable areas were identified. In GIS, all conceivable requirements (e.g. site, should be at least 500 meters from the nearest dwelling unit) are initially specified, spatial data integrated and overlaid and based on the final output obtained suitable environmentally benign sites for waste disposal are identified.