城市湖泊湿地温湿效应——以武汉市为例

选择武汉城市三环内主城区14块湖泊湿地为研究对象,采用小尺度定量测定的方法,研究城市湖泊湿地与温湿效应间的关系。结果表明:(1)城市湿地温度值与面积指数、距离指数呈显著负相关,与景观形状指数呈显著正相关(P0.05);湿度值与面积指数、距离指数、环境类型指数呈显著正相关,与景观形状指数呈显著负相关(P0.05)。其中面积指数的贡献值最大。(2)14块湖泊湿地的降温增湿效应排序为湖泊11—14湖泊6—10湖泊1—5。当湖泊湿地面积为9.2—12.2 hm2时,其降温增湿效应明显;当湖泊湿地面积为308.4hm2左右时,降温效应显著且趋于稳定,湖泊湿地面积为67.6hm2左右时,增湿效应显著且趋于稳定(P0.05)。当湖泊湿地面积达到临界值之后,多斑块离散型(Dispersive)湖泊湿地布局对整个城市环境的降温增湿效应更为显著。

Effects of urban lake wetland on temperature and humidity: a case study of Wuhan City

To study the effects of urban lake wetlands with different areas (WA), geometry (landscape shape index, LSI), and location with reference to a defined city center (DIST), and surrounding a non-built-up area proportion around 500 m of wetland (PB) on air temperature and relative humidity in summer, fourteen urban lake wetlands in central areas of Wuhan were selected. The temperature and relative humidity in summer were measured using small-scale quantitative measurement methods. Furthermore, the relationships between air temperature, relative humidity of urban lake wetlands, and WA, LSI, DIST, and PB were investigated to provide a scientific background for the construction of urban lake wetlands. The results showed that (1) the air temperature was negatively correlated with WA and DIST (P < 0.05), and positively correlated with LSI. The air relative humidity was positively correlated with WA, DIST, and PB, and negatively correlated with LSI(P < 0.05).The area of the lake wetland had the greatest effect on variations in temperature and relative humidity.(2)The benefits of urban lake wetland on temperature and relative humidity were associated with the areas of fourteen lake wetlands. Furthermore, the order was lake wetlands 11-14> lakes 6-10> lakes 1-5. The urban lake wetlands that had an area of 9.2-12.2 ha had an obvious effect on the decrease in temperature and increase in humidity. When the area of wetland was around 308.4 ha, its effect on the decrease of temperature was stable; and for the increase in humidity, the area was around 67.6 ha (P < 0.05). When the urban lake wetland area reached a certain critical value, it would have an obvious effect on the decrease in air temperature and increase in humidity with dispersive lake wetlands in the urban environment.