Optimizing Urban Form to Enhance Dispersion of Carbon Emissions: A Case Study of Hangzhou

Achieving the dual goals of “carbon neutrality and carbon peaking” will necessitate not only improving urban production and lifestyles to reduce carbon emissions but also minimizing the adverse effects of urban building elements on the diffusion of carbon emissions. This can facilitate the rapid flow of carbon emissions to high-carbon sink areas, thereby accelerating urban carbon circulation. This study calculated the carbon emissions of Hangzhou, utilized the WRF/Hysplit coupling method to simulate the city’s carbon emission diffusion status in 2020, and explored the impact of construction land layouts on carbon emission diffusion in terms of building height and building location. The results indicate the following: (1) The main sources of carbon emissions are located within the city, displaying a multi-center spatial distribution. The primary corridor for carbon emission diffusion is on the east side, where the underlying building density is relatively low. (2) As the building height increases from 24 to 36 m, the obstructive effect on carbon emission diffusion rapidly intensifies; however, this increase slows considerably once the building height exceeds 54 m. (3) The impact of buildings on carbon emission diffusion is the greatest when the distance between construction land and a carbon source area is 0 km. When this distance is 2 km, the obstructive effect of buildings significantly improves, depending on their heights. Beyond 7 km, the building height has almost no impact on carbon emission diffusion. The findings of this study may provide valuable suggestions for optimizing building heights in newly developed areas on the outskirts of cities, aiding in the effective design of construction land layouts to help China achieve its carbon neutrality and carbon peaking goals.