基于定量遥感的湘潭市城区热岛时空格局分析

Spatio-Temporal Pattern Analysis on the Urban Heat Island of Xiangtan City

利用2013年~2014年5个时相Landsat 8 OLI和TIRS数据,反演了夏季全程和冬季地表温度,反演结果绝大部分值在历史数据最高温度(日间)附近,反演结果具有一定的表征力;计算了反演区的热岛强度,分析了夏季湘潭城区地表温度的空间分布与随时间的变化情况,结果显示城市热效应空间分布格局不同时相表现出类似的模式,发现城市在夏季地表温度呈现"南高北低"和高温区沿湘江分布的情况;原先夏季高温区在冬季出了低温,表现出夏热冬冷的现象,这一定程度说明地表热效应对地表类型反应灵敏。同时分析植被指数、城市建筑物指数与城市地表温度等间关系,结果显示城市绿化对城市地表温度降低的确有一定的作用,地表温度对城市建筑物密集区敏感。这一成果对地方城市规划建设具有现实意义和借鉴价值。

Landsat 8 OLI and TIRS data,acquired in 5 date during 2013 and 2014,were used to retrieve the land surface temperature in summer and winter. The retrieval temperature close to the highest recorded one in daytime,indicated that the result was reliable. Also the heat island index was calculated to analyze the temperature pattern in different place and time. The result indicated that there was a similar mode in the spatial distribution pattern of urban heat island effect. That mode was 'high in south while low in north'and the high temperature alongside the Xiangjiang River in summer,and the place where the temperature was high in summer had a low temperature in winter,which was so called the phenomenon of heat in summer while cold in winter. To some extent,this phenomenon indicated that the heat island effect was sensitive to the land cover type. At last,the relationship between the vegetation index and urban building index and the land surface temperature was analyzed and showed the urban greening played a role in reducing the urban heat island effect and the land surface temperature was sensitive to the area of dense urban building. This result is of practical significance for and reference to the urban planning and construction of local cities.