GIS based urban land valuation model : a case study of Homagama Divisional Secretary Division

Abstract

Accurate land valuation is essential for effective urban and regional planning, real estate development, and development control processes. In Sri Lanka, conventional land valuation practices largely rely on manual methods and professional judgment, which often result in subjectivity and inconsistency, particularly in rapidly transforming suburban areas. With increasing urban expansion and infrastructure development, there is a growing need for objective, spatially explicit land valuation approaches that can support planning and valuation decision-making. This study aims to develop and validate a GIS-based land valuation model for a suburban area using spatial multi-criteria analysis. The Homagama Divisional Secretariat Division was selected as the study area due to its rapid suburban development and mixed urban–rural characteristics. Key factors influencing land value were identified through literature review and expert consultation and categorized into relevant spatial dimensions. The Analytical Hierarchy Process (AHP) was employed to determine the relative weights of selected factors, which were then integrated using a weighted overlay technique within a GIS environment. A GIS workflow was developed to generate spatial land value zones classified into low, moderate, high, very high, and extremely high categories. The model outputs were validated by comparing the generated land value zones with actual land market values collected from the study area. The validation results indicate a strong spatial correspondence between high- value zones and locations with higher recorded market values, demonstrating the model’s ability to represent relative land value patterns effectively. The findings confirm that accessibility, infrastructure availability, land use, and socio- economic characteristics significantly influence land value variations in suburban contexts. The study highlights the importance of differentiating transportation infrastructure based on actual accessibility rather than treating all road networks uniformly. Overall, the research demonstrates that GIS-based land valuation models can enhance transparency, consistency, and efficiency in land valuation and planning practices. The developed framework provides a practical decision-support tool for preliminary land value assessment and offers a foundation for future comparative and advanced valuation studies.