武汉地区风环境影响下湿地调温作用的模拟分析

Impact of Wetland on Wind and Air Temperature in Wuhan City of Hubei Province

湿地是支持城市可持续发展的生态资源之一,是生态系统的重要组成部分。风是自然界流动性比较大的气候因子,可以成为改善空气环境的重要媒介。本文旨在利用湿地和城市风环境为夏热冬冷型的武汉市实现一种无污染、低能耗的气候调解方式,缓解由于气候条件较差而带来的能源问题与城市宜居水平下降的问题。文中利用计算机模拟技术,采用相关的气象、生态数据研究了在城市风环境的影响下,武汉市的湿地资源对城市通风、降温、采暖、舒适性等环境问题的调节作用。从研究中发现湿地在城市大气环境调节方面的作用非常大。但是城市的风环境受热岛效应及城市建筑过于密集的限制,运行状态较差,致使湿地调节城市气候的潜力远未完全发挥出来。为此,本文在现状评价的基础上提出了改善风环境、充分发挥湿地效能的优化措施,并进行了相应的对比模拟实验,提出现阶段应该保护与合理利用各类湿地的建议。

Wetland, an important component of eco-system, is one of the ecological resources to support suitable development of our city. It has multiple functions such as purifying atmosphere, holding water, reducing noise, regulating climate, decomposing pollution, and it has been named ＇the kidney of the earth＇. Wind, one of floating climate factors in nature, can be vital media to improve air condition. Wuhan City（E113°41＇-115°05＇,N29°58＇- 31°22＇）, locating at the intersection of the Chang-jiang River and the Han-jiang River, belongs to subtropical moist monsoon climate and its four seasons are quite distinct. One of the benefits of this city is the abundant resources of wetland. The goal of this paper is to use wetland and wind to achieve a clean and low energy consuming environment for Wuhan city, where it is hot in summer and cold in winter. It deals with the city＇s problems of high energy consumptions and low suitable city living standard because of the extreme weather conditions. There are already a lot of domestic and oversea researches on wetland and wind environment, but none of them applies to the situation in Wuhan City well. Common effect by combining these two resources to improve city＇s climate has not been seen. This paper uses computer simulation technology and relevant climate and ecological data to analyze the regulating function of wetland, which will be used to deal with environmental problems of Wuhan city such as ventilation, cooling, heating, and comfortable living, under the influence of wind environment of the city. The paper first introduced the condition of the city＇ s climate and wetlands. Digital model of wetland and its original settings are also introduced. Then the city＇s climate conditions in days and nights of summer and days in winter are simulated. In each simulation, all the main wind directions in every season are also taken into consideration. Wetland is found to have great influence on the regulation of atmosphere environment from this study. But the wind environment of the city does not work well due to the heat island effect and the restriction of dense buildings in city, which limits the potential capacity of wetland to regulate city climate. This paper constructs some optimizing measures to improve wind environment and work efficiency of the wetland. The measures presented in this paper include setting up wind tunnels in the city, lowing down the density of city, combining wetlands＇ ecological-system, building livable and sustainable residential districts around wetlands and so on. Related simulation tests are performed and demonstrate good effects. Finally, this paper proposes to protect and reasonably use various kinds of wetlands.