Lishui, surrounded by mountains, is a small basin with a diameter of only a few kilometers, which has a strong heat collection effect. Gao made an image metaphor. In summer, the small pots in the city are like pots in the sun, and the heat around the sun is gathered at the bottom of the pot. On the other hand, the surrounding mountains also block the circulation of air near the ground, and only the narrow water surface of Oujiang River forms an air passage. Compared with Jinhua and Wenzhou, the surface wind speed in Lishui city is smaller, and the temperature exchange effect when passing through the air is greatly weakened. In addition, the distance between buildings and population in the city also causes the "heat accumulation" effect of the city. Meteorologists pointed out that the heat absorption of urban roads, roofs and other building materials is worse than that of green spaces and ponds. Although Lishui has a certain area of green space, it is still at a low level, and trees play a greater role in reducing solar radiation and shading than lawns. Judging from the current urban construction, many trees have a positive effect on alleviating urban high temperature. Follow-up: But there are many forests in Lishui Mountain, so it should not be so sultry. The weather in Hangzhou is better than Lishui when there are no mountains. .