Toward a climate-resilient desert, coastal city: High-resolution LCZ–WRF modeling of transformative urban greening scenarios

Urban heat stress poses a critical challenge for rapidly urbanizing cities in arid coastal environments, where extreme summer temperatures, limited natural vegetation, and strong land-sea interactions exacerbate the urban heat island (UHI) effect. This study investigates the thermal and energy impacts of large-scale urban greening in Doha, Qatar, using a high-resolution configuration of the Weather Research and Forecasting (WRF) model coupled with the Building Energy Model (BEM) and a Local Climate Zone (LCZ) framework. A four-domain nested modeling setup is employed, with horizontal grid spacing refined to 400 m over the Doha metropolitan area, enabling explicit representation of urban morphology, coastal circulations, and intra-city thermal heterogeneity. Three greening scenarios representing 25%, 50%, and 75% increases in vegetation cover are simulated relative to an LCZ-based baseline during a representative summer heat period (5-10 July 2024). Model performance is evaluated against surface meteorological observations from urban-core and coastal monitoring stations, demonstrating satisfactory skill in reproducing near-surface temperature and wind characteristics. Results reveal a pronounced diurnal asymmetry in greening effectiveness, with modest and spatially heterogeneous daytime cooling but substantially stronger nighttime temperature reductions. The largest cooling occurs within compact and large low-rise urban zones, where nighttime temperature decreases exceeding 5 degrees C are simulated under the most extensive greening scenario, indicating a transformative reduction in UHI intensity. The thermal benefits translate into significant reductions in cooling energy demand, quantified using building energy simulations in OpenStudio, with the two most common residential buildings in Doha, a mid-rise apartment building and a detached villa, which show a cooling energy use reduction by 4% at the urban-core site under the 75% greening scenario. These findings demonstrate that urban greening can deliver substantial thermal and energy benefits in hyper-arid cities, particularly when targeted toward dense urban environments. The study provides a morphology-aware modeling framework to support climate-resilient urban planning and the large-scale implementation of nature-based solutions in similar desert coastal cities.