Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks reduce local temperatures by up to 4 degrees Celsius during heatwaves. However, the researchers noted that this cooling effect depends on the park's size and tree density. For example, small gardens with scattered trees have minimal impact, while large wooded areas can create a significant 'cool island'. Interestingly, the study also showed that adding water features, like ponds, increases the cooling effect by about 15%, but only if the water is shaded. Without shade, evaporation can actually increase humidity, making the area feel hotter.
❓ Согласно лекции, какой фактор является ключевым для того, чтобы водные объекты эффективно охлаждали городской парк?