Department of Geography, National University of Singapore, Singapore 117570, Singapore.
School of Geographical Sciences and Urban Planning, Arizona State University, Tempe, AZ 85287, USA.
Sci Total Environ. 2018 Dec 1;643:738-750. doi: 10.1016/j.scitotenv.2018.06.209. Epub 2018 Jun 27.
This study used remote sensing imagery to characterize land use/cover patterns and to derive land surface temperature (LST) of Greater Yangon, the largest urban agglomeration in Myanmar, to provide insights into the association between land use/cover and seasonal, daytime, and nighttime LST change. Analysis of Landsat images from 1987 to 2015 showed urban expansion radiating from the city center and along prominent rivers, with major increases in built-up land (6.4%) and grassland (10.1%) and consequent decline in agricultural land (17%). Examination of MODIS LST showed that agricultural land was warmer than the city core during daytime in hot seasons, while in cold seasons, the city core was warmer than its rural surroundings during both daytime and nighttime. Correlation analysis revealed stronger association between built-up land and nighttime LST from 2000 to 2015, suggesting an increased surface urban heat island effect. Furthermore, this study highlighted two main differences from prior work on the influences of land use/cover on LST. First, the predominant land use/cover type that had great overall impact on LST was agricultural land, marked by its statistically significant correlation coefficients across all time periods of analysis. Such finding emphasized the influence of agriculture and related practices on the atmosphere and climate system. Second, the temporal analysis of LST highlighted a stronger and more complicated role water played because of its negative correlations with daytime LST and positive correlations with nighttime LST. The findings of this study underscored more complex effects of land use/cover on the spatial and temporal variations of LST in Yangon, compared to prior work that generally reported high LST in the urban areas. These insights improve the understanding of the land change consequences on the temporal dynamics of LST and can support sustainable land use planning for the better well-being of the inhabitants in Greater Yangon.
本研究利用遥感影像来描述土地利用/覆盖模式，并获取缅甸最大城市群仰光的地表温度（LST），以深入了解土地利用/覆盖与季节、日间和夜间 LST 变化之间的关系。对 1987 年至 2015 年期间的 Landsat 影像进行分析表明，城市从市中心向主要河流辐射扩张，建成区（6.4%）和草地（10.1%）大幅增加，而农业用地（17%）则相应减少。对 MODIS LST 的研究表明，在炎热季节的白天，农业用地比城市核心区更热，而在寒冷季节，城市核心区在白天和夜间都比周围的农村地区更热。相关分析显示，2000 年至 2015 年间，建成区与夜间 LST 的相关性更强，表明地表城市热岛效应增强。此外，本研究还突出了两个与之前关于土地利用/覆盖对 LST 影响的研究的主要区别。首先，对 LST 有总体重大影响的主要土地利用/覆盖类型是农业用地，这在整个分析时间段内的统计显著相关系数中得到了体现。这一发现强调了农业及其相关实践对大气和气候系统的影响。其次，LST 的时间分析突出了水的作用更加复杂和强烈，因为它与日间 LST 呈负相关，与夜间 LST 呈正相关。本研究的结果强调了土地利用/覆盖对仰光 LST 的时空变化的影响更加复杂，与之前普遍报告城市地区 LST 较高的研究相比，这为理解土地利用变化对 LST 时间动态的影响提供了更多的认识。这些见解有助于更好地了解土地变化对 LST 时间动态的影响，从而支持可持续的土地利用规划，以提高大仰光地区居民的福祉。
