• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.84-97
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• 2016

This study was to investigate the user's thermal environments of the children's parks according to pavements and sunscreen types during periods of heat waves. The measurements were conducted at the sand pits, rubber chip pavement, shelters, and green shade ground of the two children's parks located in Jinju, Korea(Chilam: $N\;35^{\circ}11^{\prime}1.4{^{\prime}^{\prim}}$, $E\;128^{\circ}5^{\prime}31.7{^{\prime}^{\prime}}$, elevation 38m, Gaho: $N\;35^{\circ}09^{\prime}56.8{^{\prime}^{\prime}}$, $E\;128^{\circ}6^{\prime}41.1{^{\prime}^{\prime}}$, elevation 24m) over three days during 11-13, August, 2016. The highest ambient air temperatures at the Jinju Meteorological Office during the three measurement days were $35.9{\sim}36.8^{\circ}C$, which corresponded with the extremely hot weather. A series of experiments measured air temperature, relative humidity, wind velocity, black globe temperature, and long-wave and short-wave radiation of the six directions 0.6 m above ground level. The wet bulb globe temperature(WBGT) and the universal thermal climatic index(UTCI) were used to evaluate thermal stress. Surface temperature images of the play equipment were also taken using infrared thermography. Surface temperatures of the play equipment and grounds were used to evaluate burn risk through contact with playground materials. The results showed the following. The maximum air temperatures averaged over 1-hour period for three days were $36.6{\sim}39.4^{\circ}C$. The sun shades reduced those temperatures by up to $2.8^{\circ}C$(green shade) and $1.0^{\circ}C/2.3^{\circ}C$(shelters). The minimum relative humidity values averaged over 1-hour period for three days were 44~50%. The sun shades increased those humidity values by up to 6%(green shade) and 4%/6%(shelters). The risk of heat related illness at the measurement sites of the children's parks were extreme and high in the daytime hours. The maximum WBGT values averaged over a 30-minute period for three days were $31.2{\sim}33.6^{\circ}C$. The sun shades reduced those WBGT values by up to $2.4^{\circ}C$(green shade) and $0.5^{\circ}C/2.1^{\circ}C$(shelters) compared to sandpits, but would not block the risk of heat related illness in the daytime hours. The category of heat stress at the measurement sites of the children's parks were extreme and very strong in the daytime hours. The maximum UTCI values averaged over a 30-minute period for three days were $39.9{\sim}48.1^{\circ}C$. The sun shades reduced those UTCI values by up to $7.8^{\circ}C$(green shade) and $4.1^{\circ}C/8.2^{\circ}C$(shelters) compared to sandpits, but could not lower heat stress category from extreme and very strong to strong and moderate in the daytime hours. According to the burn threshold criteria when skin was in contact with playground materials, the maximum surface temperature of the stainless steels($70.8^{\circ}C$) surpassed three seconds $60^{\circ}C$ threshold for uncoated steel, that of the rubber chip($76.5^{\circ}C$) surpassed five seconds $74^{\circ}C$ threshold for the plastic, that of the plastic slide($68.5^{\circ}C$) and seats($71.0^{\circ}C$) surpassed the one min $60^{\circ}C$ threshold for plastic, respectively. The surface temperatures of shaded play equipment were lower approximately $20^{\circ}C$ than those of play equipment exposed to the sun. Therefore, sun shades can block the risk of burns in daytime hours. Because of the extreme and high risk of heat related illness and extreme and high heat stress at the children's parks during periods of heat waves, parents and administrators must protect children from the use of playgrounds. The risk of burn when contact with play equipments and grounds at the children's parks during periods of heat waves, was very high. The sun shades are essential to block the risk of burn from play equipments and grounds at the children's parks during heat waves.