Today we're discussing the impact of urban green spaces. A recent study in Melbourne found that parks can reduce local temperatures by up to four degrees Celsius during heatwaves. Interestingly, the effect is strongest when parks are larger than two hectares and include a mix of trees and open grass. The study also noted that residents living within 500 meters of a green space reported better sleep quality, possibly due to cooler nights. However, the researchers warned that simply planting more trees in streets may not have the same cooling benefit, as pavement retains heat. They recommend prioritizing large, connected green areas in city planning.
❓ According to the lecture, what condition is necessary for urban parks to have the strongest cooling effect?
A. They must be located within 500 meters of residential areas.
B. They should be larger than two hectares and have mixed vegetation.
C. They need to include a large lake or water feature.
D. They should be planted with street trees in a linear pattern.
✅ 正确答案
They should be larger than two hectares and have mixed vegetation.