The South Australian State Emergency Service (SES) recently conducted thermal imaging in Mount Gambier, revealing that surface temperatures significantly exceeded ambient air temperatures on a 40-degree Celsius day in January. A lawn bowls green registered a surface temperature of 86.75 degrees Celsius, which was more than double the air temperature. This data provides insights into the urban heating phenomenon and its local impacts.
A lawn bowls green registered a surface temperature of 86.75 degrees Celsius, which was more than double the air temperature.
SES Drone Deployment and Key Findings
The SES utilized a drone equipped with thermal imaging capabilities during a routine test flight conducted by chief remote pilot Brad Flew in January. This deployment enabled the measurement of various surfaces, including astroturf, fake grass, concrete, and bitumen. The findings provided crucial insights into broad temperature variations, extending beyond typical warnings about hot footpaths and roads. The recorded 86.75 degrees Celsius on a lawn bowls green starkly highlighted how some surfaces reached temperatures more than twice the official air temperature.
Understanding Urban Heating
These extreme surface temperatures are attributed to urban heating, a phenomenon where non-living surfaces absorb and retain heat. This causes local environments to become significantly warmer than the ambient air.
Paul Cheung, a postdoctoral research fellow in urban microclimates at Western Sydney University, explained the mechanics. Surfaces such as concrete and bitumen absorb more sunlight compared to living surfaces like grass and trees. Unlike vegetation, these non-living materials do not absorb water or cool the surrounding area through transpiration. Living surfaces, conversely, use water absorption and transpiration to help cool their environment.
Local Impacts on Activities and Policies
The high surface temperatures have significantly affected local activities, particularly lawn bowls. Ian Von Stanke, a lawn bowls player in Mount Gambier, described the intense heat emanating from the greens. Players have adopted personal cooling methods, such as wetting cloths under hats or using reflective inserts in their shoes, to manage the conditions.
Mr. Von Stanke has advocated for more localized heat policies for bowls competitions on the Limestone Coast. Current rules for pennant games often apply when temperatures are forecast to reach 37 degrees Celsius in Naracoorte, approximately an hour away. However, specific heat rules are reportedly absent for local tournaments, which has led to players experiencing heat-related issues.
Mitigation Strategies and Urban Planning
Experts emphasize the crucial role of urban planning in managing high temperatures. Abby Mellick Lopes, a professor of social design at the University of Technology Sydney, stated that appropriate planning rules, including the provision of shade trees, are essential for combating heat in communities. She also suggested that current European-style housing designs may not be suitable for the Australian climate.
Thermal imaging data visually demonstrates significant temperature differences between areas with and without tree canopies.
Thermal imaging data visually demonstrates significant temperature differences between areas with and without tree canopies, underscoring the effectiveness of natural shade in heat mitigation.