Appropriate solid waste dumping site selection for Patna City by using GIS-TOPSIS method

In this study, landfill site selection for Patna City is conducted through the integration of Geographic Information System (GIS) and Technique for Order of Preference by Similarity of Ideal Solution (TOPSIS) methods. A comprehensive analysis is performed using ArcGIS software 10.8.2 and the raster calculator tool to create the ultimate suitability map by combining various layers with their assigned weights. GIS mapping highlights red zones as constraints (e.g., agriculture, cantonment, commercial, industrial, railway), while blue areas signify suitability, with agriculture covering expansive regions. Factor mapping for landfill suitability, considering the distance, roads, settlements, slope, drainage, water bodies, and soil types, aids informed decision-making in waste disposal site selection. The raster calculator tool in ArcMap is employed to identify aggregated constraint areas, resulting in a map showcasing both restricted and suitable landfill locations. Relative closeness (RC) values reveal the suitability of different areas for solid waste dumping, ranking Area 2 as the most suitable, followed by Area 1 and Area 3. The final suitability map classifies areas into distinct categories, ranging from not suitable to most suitable. Results indicate that 60% of the study area is not suitable, 10% is most suitable, and the remaining 30% is categorized as least suitable and less suitable. The suitability map assists city planners in identifying appropriate waste disposal locations, thereby supporting the development of an effective waste management plan for Patna City and ensuring responsible waste disposal practices. The significance of this study lies in the use of GIS and TOPSIS methods for landfill site selection in Patna City, which provides an efficient and objective approach to solid waste management. The study's results can be used as a tool for decision-makers to identify suitable landfill sites and make informed decisions for effective waste management.