Circuit VRC: A circuit theory-based ventilation corridor model for mitigating the urban heat islands

Abstract

This paper reports on Circuit VRC, a ventilation corridor model that integrates circuit theory and ventilation resistance coefficient (VRC) to address urban heat island mitigation. Taking Wuhan's main urban area as an example, the Circuit VRC model was employed to identify the paths and barriers of the urban ventilation corridors and simulate the airflow at a macro scale. Combined with land surface temperature (LST) maps, the accuracy of the Circuit VRC model was evaluated. This paper further proposes an optimization strategy for ventilation corridors based on this model. The results indicated that (1) The proposed Circuit VRC model exhibited high reliability. Under the prevailing wind direction, the mitigation effect of Circuit VRC-based ventilation corridor areas on urban heat islands is on average 46.3% higher than that of non-corridor areas. (2) The airflow values in Circuit VRC-based ventilation corridors showed a non-linear correlation with LST. As the airflow value increases from 0 to 0.5, the LST reduces significantly. (3) The constructed ventilation corridors can be greatly optimized by using the floor area ratio (FAR)-controlled method in the Circuit VRC model. The maximum increase in airflow value in the ventilation corridor caused by a 0.1 FAR decrease within the barriers is 17.8%. The model proposed in this study provides crucial technical support for mitigating urban heat islands.