During the summer of 2022, a record-breaking heatwave occurred in the Yangtze River Delta urban agglomerations, causing significant damage to health and livelihoods of local residents. While most studies attribute the heat wave to abnormal atmospheric background conditions (e.g. anticyclonic circulation, warm advection, etc.), investigation on contributions from urban effects in this heatwave is limited. Here we used the Weather Research and Forecasting (WRF) model coupled with the Urban Canopy Model (UCM) to quantify the heterogeneous contributions of urban effects to this extreme heat wave and to the heat-related morbidity over Yangtze River Delta region, by sensitivity numerical experiments separating land-use and anthropogenic-heat effects. The contribution of land use effect and anthropogenic heat effect to this extreme heat wave event peaked around 49% and 13%, and the contribution of the combined effect is peaked about 51%. In addition, the attributable number of hospital admissions of daily minimum temperature related to urban effects can reach 4.50/km2 in this heatwave event in Shanghai city, where the land use effect plays a dominant role.
 

Yangtze River Delta,Heat wave,Urban effect,WRF-UCM