Urban vegetation, Nature-Based Solutions, thermal stress, urban heat island, Najaf Governorate, sustainable urban planning

ABSTRACT: Urban thermal stress has become one of the most critical environmental challenges facing rapidly expanding cities, particularly in arid and semi-arid regions such as Najaf Governorate, Iraq. Accelerated urbanization, population growth, extensive impervious surfaces, and the decline of green spaces have intensified the urban heat island effect, leading to elevated air and surface temperatures and increased thermal discomfort for urban residents. Nature-Based Solutions (NBS), especially urban vegetation, represent a sustainable and environmentally friendly approach to mitigating urban thermal stress. Urban plants, including street trees, public parks, green belts, and urban gardens, play a vital role in regulating the urban microclimate through shading, evapotranspiration, reduction of solar radiation absorption, and improvement of surface thermal properties. These processes collectively contribute to lowering ambient temperatures, enhancing thermal comfort, and reducing energy demand for cooling in urban areas. This study aims to evaluate the effectiveness of urban vegetation as a nature-based solution for mitigating thermal stress in Najaf Governorate. The research focuses on analyzing the relationship between vegetation cover distribution and urban temperature patterns, considering land-use characteristics and urban morphology. Particular attention is given to the selection of plant species suitable for the local climatic conditions of Najaf, emphasizing native and drought-tolerant species that can withstand high temperatures, water scarcity, and harsh environmental conditions. The significance of this research lies in its contribution to sustainable urban planning and climate adaptation strategies in Najaf Governorate. By integrating urban vegetation into urban planning policies, cities can enhance environmental resilience, improve public health, and promote long-term ecological sustainability. The findings are expected to support decision-makers and urban planners in adopting nature-based solutions as a cost-effective and adaptive strategy to reduce thermal stress and improve the livability of cities under ongoing climate change.