Surface urban heat island effect and its spatiotemporal dynamics in metropolitan area: a case study in the Zhengzhou metropolitan area, China

The deterioration of the urban surface thermal environment has seriously affected regional environments and human health, becoming a critical ecological problem faced by cities worldwide. This study focused on heat island effect in metropolitan area selected emerging Zhengzhou, China, as case study. Based MODIS land temperature data obtained from Google Earth Engine intensity (SUHII) was calculated its temporal spatial dynamics were analyzed 2003 to 2022. main findings indicated that core city area, had strongest with day 1.10°C night SUHII 1.39°C). Generally, average annual higher during than at night, maximum value detected summer (2.43°C). showed an increasing trend especially period. It decreased obviously centers day, while it increased outer areas night. results this contributed understanding spatiotemporal Zhengzhou area.