Quantification of contribution of climate change and land use change on urban ecosystem service using multi-scale approach

• Both land use change and climate change have a negative impact on HMI. • Climate change is the primary factor affecting the variation in WY. • Land use change is the dominant factor affecting the change in HMI. • The influence of climate change on WY is inconsistent. • Land use change and climate change effects on the HMI shows spatial variability. The changes of land use and climate have significantly impacted urban ecosystem services (ES). Investigating the effects of urbanization and climate change on urban ES is essential for ensuring sustainable urban development and management. Water Yield (WY) and Urban Cooling are key urban ES in response to climate change, this study employs scenario simulation method to set up 9 scenarios, including 3 baseline and 6 simulated scenarios, which are further analyzed using a contribution index to investigate the impacts of climate change and land use on WY and urban cooling. Results showed that 1) From 2000 to 2020, Shanghai exhibited an increase in temperature and precipitation. Land use change from 2010 to 2020 increased by 2.17 % compared to 2000 to 2010. The primary land use type shifted from Cultivated Land to Artificial Surfaces, but both land use type exhibited a downward trend. 2) From 2000 to 2020, the WY from Cultivated Land initially increased and then decreased, with an average magnitude of 193.6Mt every year, while the WY from Artificial Surfaces consistently increased by 1171.5Mt. The Heat Mitigation Index (HMI) of Cultivated Land, Artificial Surfaces, Ocean, and Grassland all declined, while Water Bodies’ HMI increased from 0.35 to 0.38, and Forest’s HMI initially increased then decreased. Overall, Shanghai’s HMI showed a downward trend. 3) From 2000 to 2010, changes in land use led to a reduction in HMI by 0.088 and an increase in WY by 48.73 mm. Climate change caused HMI to decrease by 0.01 and WY to decrease by 7.95 mm. From 2010 to2020, land use change caucused a decrease in HMI by 0.064 and an increase in WY by 13.01 mm. The effect of climate change on HMI is less significant compared to WY, which increased by 388.26 mm. From 2000 to 2020, land use change led to a reduction in HMI by 0.13 and an increase in WY by 61.68 mm, while climate change caused a decrease in HMI by 0.002 and an increase in WY by 280.44 mm. Climate change is the dominate influencing factor for WY, while land use change has stronger effect on HMI. Meanwhile, the influence of climate change on WY is inconsistent, and the impact of land use change and climate change on the HMI exhibits spatial heterogeneity. These findings will assist sustainable urban development in Shanghai.