基于TM/ETM~+影像的绵阳春秋两季城市热环境特征对比分析

选取中等城市——四川省绵阳市为研究对象,以2000年(代表秋季)、2001年(代表春季)TM/ETM+遥感影像为数据源。在基于影像算法反演地表温度的基础上,对研究区春、秋两季热场剖面、建成区范围内热力景观斑块和城市热岛效应进行研究。结果表明:(1)无论春季还是秋季,地表温度高低与下垫面性质具有较大相关性,水体和植被覆盖较好的区域呈现低温,而水泥、沥青等不透水面温度较高;(2)秋季相对春季而言,温度相对较高的热力景观类型面积减少,而温度较低的热力景观类型面积增加。分析热力景观异质性指数发现,优势度指数值春季大于秋季,说明春季存在较明显的优势斑块;(3)运用城乡平均温度对比法和热岛面积指数法,计算春季热岛强度值为1.77℃,秋季热岛强度值为0.78℃,由此说明,在该时段内春季的城市热岛效应强于秋季。

Analysis on the Characteristics of Urban Heat Environment Between Spring and Autumn in Manyang City Using TM/ETM~+

The paper takes Mianyang city as the study area and the TM/ETM+ images of 2000 and 2001 as the data source.After retrieving the land surface temperature with the imaging algorithm,the author analyses the profile of thermal field in spring and autumn,the thermal landscape patch within built-up area and the urban heat island effect.The results show that first the relationship between land surface temperature(LST) and the characteristics of the underlying layer is significant in spring and autumn,and the temperature of water and the area with better vegetation coverage are lower than impervious surface such as cement,asphalt and so on;secondly,from spring to autumn,the area of thermal landscape with high temperature is reduced,however,the area of thermal landscape with low temperature increases.Base on the analysis of thermal landscape heterogeneity index,the dominance index is greater in spring than autumn,and it shows that spring has the relatively preponderant plaque;thirdly,using the comparison method between the average temperature of urban and rural,and the method of the heat island area index,the Urban Heat Island Intensity(UHII) is 1.77℃ in spring,in autumn the value becomes 0.78℃,and it shows that urban heat island effect is much stronger in spring.