Beyond surface area: Integrating volumetric green infrastructure into planning regulations to enhance equity and sustainability in an arid city

Urban green infrastructure (UGI) provides a vital nature-based solution for enhancing sustainability in arid cities, yet its adoption in formal planning frameworks remains limited. This study examines the spatial distribution, equity, and planning implications of UGI in Al Ain, UAE, a rapidly expanding inland desert city. Using ultra-high-resolution (9-cm) aerial imagery and 1-m LiDAR data, we applied a support vector machine (SVM) classifier to produce a detailed land-cover map with an overall accuracy of 90.2% and a three-dimensional assessment of vegetation volume. UGI covers 16.64% (40.76 km²) of the urban extent, providing a relatively high per-capita green space provision of 62.14 m². Despite this, spatial analysis reveals pronounced inequities, with vegetated areas clustering in historic, oasis-adjacent neighborhoods, while newer high-density districts emerge as “cold spots” with minimal vegetation. Current municipal planning regulations, which prioritize built density and visual landscaping over ecological functionality, exacerbate these disparities. Integrating volumetric vegetation metrics and per-capita thresholds into planning codes can improve spatial equity, strengthen ecosystem services, and mitigate urban heat island effects. This study advances performance-based urban planning in arid environments and demonstrates the potential of high-resolution geospatial methods to guide sustainable, equitable urban development.