Weather condition and Urban infrastructure for sustainable water supply protection from water meter frost: the case of Seoul

Wintertime water meter frost is a substantial threat to sustainable water supply. However, little is known about the social and environmental conditions associated with its occurrence. This study identifies characteristics of water meter frost in Seoul, South Korea, by examining natural and anthropogenic conditions, such as local weather and urban infrastructures. The deterministic threshold of seasonal water meter frosts is the number of cold days below -10 degrees C. The wall-type water meter was the first to freeze during a cold surge, whereas the manhole-type water meter froze gradually, which increased after a persistent cold surge of more than three days. In addition, deteriorated buildings (older than 30 years), narrow pipes with diameters of 15-20 mm, and housing types such as townhouses and shopping malls were found to be vulnerable to frost. The critical thresholds proposed in this study are necessary for maintaining a stable water supply in megacities in cold regions, world-wide.