EVALUATING PUBLIC URBAN GREEN SPACES: A COMPOSITE GREEN SPACE INDEX FOR MEASURING ACCESSIBILITY AND SPATIAL QUALITY

Abstract. Greenspaces (GSs) available to the public for recreational, environmental, and aesthetic purposes are termed Public Urban Green Spaces (PUGS). Accessibility to PUGS is one of the main pre-requisite for their frequent use. With rising urbanization and inequitable distribution of GSs, a significant portion of the population remains inaccessible to the benefits provided by PUGS. Therefore, it is essential to have tools to evaluate these GSs. This study evaluates the accessibility and spatial quality of various hierarchies of PUGS using GIS-based analysis in Dehradun, India. Accessibility is assessed using network analysis, aesthetics is determined by the presence of bird population and waterbody, the surface index is determined based on NDVI thresholding, and affordability, and spaciousness are computed based on survey and GIS data. The indices are combined to form a composite green space index (CGSI) using analytical hierarchy process. CGSI shows that most of the PUGS in Dehradun have relatively poor accessibility and quality. As per World Health Organization (WHO) guidelines for providing a minimum of 9m² of GS for each person, Dehradun lies way behind, providing 2.02m²/person. The lower hierarchy PUGS, notably totlots, which are crucial for young children’s physical, mental, and cognitive development, is quite limited. On the contrary, city parks are well distributed with moderate to good accessibility and quality. CGSI is a comprehensive index encompassing different characteristics of GSs and serves as a valuable tool for setting goals, prioritizing investments, identifying areas in need of improvement, and potential locations for future GS development.