The Effects of Heat Stress on Urban Populations and the Electricity Grid

The objective of this study is to characterize the regional climate effects of high-density megacities. One characteristic of high-density megacities is the urban heat island (UHI) effect. The impervious surfaces which characterize the urban built environment absorb and retain solar insolation; the displacement of trees and vegetative surfaces reduces the cooling effects of shading and evapotranspiration. UHI creates stresses on urban populations and the electricity grid. Green infrastructure involves a transformation of the urban landscape, in which pervious surfaces and vegetation replace impervious surfaces. The increased vegetation cover has broad impacts on urban spaces. It mitigates the impact of the urban heat island, thus minimizing the effects of heat stress on urban populations and urban infrastructure, such as the electric grid. It also creates green spaces throughout the city for urban residents.

In this study we will analyze the hourly electricity load curve for examine four utility zones in South Eastern New York State (SENY): New York City, Long Island, Westchester and Putnam Counties. We will correlate electricity demand data with measures of urban form (percent impervious surface), climate (surface temperature, insolation and solar heat gain), and health outcomes (hospital admissions for heat stroke and asthma.) Based on the observed relationship between urban form, energy demand, and health outcomes we will simulate the expected environmental and social impacts of green infrastructure. The Urban Livability Index(ULI), which we construct from temperature readings and demographic data, will be utilized to identify populations particularly vulnerable to temperature extremes. The index will serve as a tool to develop a baseline analysis and understand the impacts of green infrastructure from a public health perspective.