赣西三市热环境时空演变特征及影响因素

Spatial-temporal evolution characteristics and influence factors of thermal environment in three cities of western Jiangxi

以赣西三市为研究区域,采用2002、2016年2个时段的TM/OLI/TIRS影像数据,获得辐射亮度温度和土地利用/覆被分类数据,借此分析热环境时空演变特征、热力景观格局指数变化以及影响热环境演变的因素,旨在为改善赣西城市热环境问题提供科学的依据。结果表明:随着城市化发展,近15年(2002-2016年)来,赣西三市热岛效应明显增强,但不同区域发展程度有所不同,热岛效应强度总体增加的趋势为:萍乡>宜春>新余;从热环境分布来看,三市南部地区低温与次低温面积范围相对较多,且呈现扩大趋势;从热环境景观格局演变来看,三市的中温区斑块优势度降低明显,破碎化程度加强,宜春和新余市区次低温与次高温斑块优势增多并且有形成大斑块的趋势;从热环境贡献指数来看,建设用地对热环境贡献最大,水体和林地则对城市热岛效应有显著的抑制作用。

Based on the TM/OLI/TIRS image data of 2 periods in 2002 and 2016 in three cities of Western Jiangxi, the radiation brightness temperature and land use/cover classification data were obtained, according to which the spatial-temporal evolution characteristics of thermal environment, the change of thermal landscape pattern index and the factors affecting the evolution of thermal environment were analyzed, so as to provide a scientific basis for ameliorating the urban thermal environment in Western Jiangxi. The results show that, with the development of urbanization, the heat island effect of the three cities in west Jiangxi had increased obviously in the last 15 years (from 2002 to 2016), but with different degree. The intensity increase of the heat island effect in Pingxiang City was higher than that in Yichun, and still higher than that in Xinyu. From the distribution point of view, the low temperature and sub-low temperature area mainly distributed in the southern region of the three cities and were increasing as time went. In view of the landscape pattern evolution, the dominance of the middle-temperature patches in the three cities decreased obviously, and the degree of fragmentation increased. The dominance of sub-low temperature and sub-high temperature patches in Yichun and Xinyu urban areas increased and seemed to form large patches. And from the view of the thermal environment contribution index, the construction land contributed most to the thermal environment, while water and woodland significantly inhibited the urban heat island effect.