基于遥感的西安市热力景观格局演变

Evolution of the Thermal Landscape Patterns in Xi′an City Based on Remote Sensing

基于1992—2013年3期Landsat系列遥感影像,反演出了西安市的地表温度,采用温度归一化分级方法对地表温度进行等级划分,并引入景观生态学中景观格局的研究方法,通过热力景观指数分析,对西安市热力景观格局及其演变特征进行了探讨。结果表明:1992—2013年西安市的热岛效应逐年增强,热力景观格局呈现出较大的时空差异。20多年来,热力景观从以次中温区为优势斑块连片分布的空间格局,转变为以次高温区、中温区等多种热力斑块镶嵌散布的空间格局,热力景观的破碎化程度不断提高,各热力斑块分配的均匀度、景观格局的丰富度和复杂度均稳步增加,人类活动对热环境的扰动持续而稳定。

Three Landsat images of Xi＇an from 1992 to 2013 were used to retrieve land surface temperatures （LST）, which were then classified into 5 classes by means of a normalized classification method. The thermal landscape patterns and the evolution characteristics were discussed through the analysis of thermal landscape indexes by using the research method introduced from landscape ecology. The results showed that the heat island intensity increased and the thermal landscape pattern presented great spatiotemportal difference. Dominated by large areas of sub-middle temperature region in 1992, the thermal landscape has changed to a mosaic distribution pattern mixed by multi-thermal landscape patches, including sub-high temperature region, middle temperature region and so on in 2013. The fragmentation degree intensified, and the degree of uniformity, richness and complexity enhanced steadily. Human activities have long term and steady disturbance to the urban thermal environment.