GIS and Remote Sensing-Based Site Suitability Analysis for Wastewater Treatment Plants in Urban Regions

Abstract

Site selection for urban wastewater treatment plants (WWTPs) is a critical planning task, balancing environmental protection, public health, infrastructural feasibility, and cost constraints. Geographic Information Systems (GIS) combined with Remote Sensing (RS) offer powerful tools for multi-criteria site suitability analysis. This paper reviews pre-2017 studies where GIS and RS have been applied for WWTP site selection in urban contexts. Case studies from Omdurman (Sudan), Muscat (Oman), Shollinganallur (India), Debre Berhan (Ethiopia), and general methodologies highlight workflows using multi-criteria decision analysis, weighted overlay, AHP (Analytic Hierarchy Process), and fuzzy logic integrated within GIS. These studies combine layers such as slope, elevation, land use, proximity to roads and water bodies, soil type, groundwater depth, and land cover to generate suitability maps. Remote sensing data (e.g., DEMs, land cover imagery) support spatially accurate layer creation. The proposed general methodology features spatial data collection, criterion standardization, weight assignment via AHP, raster overlay analysis, and constraint masking. Key findings include enhanced precision in identifying optimal sites, improved environmental safeguards, and stakeholder-supported transparency. Benefits include spatially explicit decision support, replicability, and integration of physical and technical factors. Drawbacks involve data availability issues, subjective weight assignments, and limitations in spatial resolution. This synthesis provides a structured workflow and policy insights for planners aiming to deploy GIS/RS-based site selection systems for urban WWTP planning.