Secondary Cooling Strategies for Low rise Urban Settlements in Hot-Arid Elazig City

Background: Outdoor Thermal Comfort (OTC) is a critical factor in urban sustainability, particularly in hot-arid climates where excessive heat exposure affects human well-being and urban livability. In the wake of increased urbanization and climate change, ensuring comfortable outdoor environments is essential. This study investigates secondary mitigation strategies to enhance OTC in low-rise settlements, focusing on Elazığ, Türkiye, a city with a distinctive climate and pre-earthquake urban structure.

Objectives: The main objectives of this research are:

• To analyze outdoor OTC using secondary mitigation strategies through microclimate simulations using ENVI-met.
• To determine which urban design parameters in low-rise settlements, including green elements, building surface albedo, and urban geometry, significantly impact Mean Radiant Temperature (MRT) values.

Methodology: This study employs a four-stage methodology to assess the impact of secondary mitigation strategies on OTC across four different low-rise urban settlement geometries. (1) Urban Geometry Analysis: Identifying and categorizing low-rise urban structures based on orientation, aspect ratio, and Sky View Factor (SVF) to establish baseline conditions. (2) Baseline Modeling: Simulating the existing urban layout using ENVI-met with a 2x2 m grid resolution, allowing a detailed evaluation of microclimatic conditions and MRT variations. (3) Scenario Development:  Creating different mitigation strategies by integrating variations in orientation, reflective surface materials, and shading configurations with different levels of canopy cover to assess their impact on OTC. (4) Statistical Evaluation:  Applying ANOVA Tukey HSD tests to quantitatively assess the effectiveness of these strategies in reducing heat stress and identifying how MRT changed under different mitigation scenarios.

Expected Outcomes: After the earthquake, Elazığ has experienced a shift toward low-rise settlements, leading to unplanned urbanization. This study is crucial for guiding climate-responsive urban planning and preventing uncontrolled urban sprawl. 

Keywords:  Outdoor Thermal Comfort (OTC), Hot-Arid Climate, MRT, PET, ENVI-met, Urban Heat Mitigation