Turning Geospatial Data into Planning Decisions: Evaluating a Participatory Accessibility Model for Urban Drinking Water

Abstract. Spatial accessibility models are widely used in infrastructure planning, yet quantitative evaluation against lived access conditions remains rare. This study implements a quality-weighted E2SFCA model of drinking water access in Kano and Lagos, Nigeria, and evaluates grid-level predictions against participatory validation data. Results show limited overall agreement (macro F1: 0.20–0.23) and context-dependent class bias. Severe deprivation is over-detected in Kano but under-identified in Lagos. Findings highlight the necessity of participatory validation when translating geospatial accessibility modelling into defensible planning interpretation.