Modeling intra-urban extreme heat exposures with fine-scale land use data

Climate models suggest that large United States (U.S.) urban populations will disproportionately experience extreme heat, in part due to the urban heat island (UHI) observed in metropolitan areas. The System for Integrated Modeling of Metropolitan Extreme Heat Risk (SIMMER) is a NASA-funded project aimed at characterizing and addressing extreme heat risk through interdisciplinary approaches. SIMMER focuses on two cities, one of which is Houston, Texas. Houston is currently experiencing trends of increasing populations, changing demographics and urban sprawl. Houston's changing UHI – which is substantially influenced by urban morphology and vegetation – poses a potential challenge to public health and planning officials interested in reducing exposure to extreme heat. Recent regional climate simulations performed at the National Center for Atmospheric Research suggest that the number of ‘high heat stress' days and nights in Houston will more than double by mid-century, raising the potential for increased exposure to extreme heat. We employ a simplified approach to modeling the distribution of temperature for current and future (2040) Houston, using high-resolution (1km) climatic and fine-scale land use (parcel-level) data. We will present results from meteorological and land use surface modeling components of SIMMER for Houston, Texas. We will focus on a series of sensitivity simulations that evaluate how changes in the urban form, derived from parcel-level present and future land use types, exhibit changes in the intra-urban temperature distribution with 1°C incremental climate perturbations. The results of these experiments will be discussed to reflect how alterations made to the urban environment via land use changes influence the distribution of heat, and consequently could impact climate change adaptation strategies.