Abstract

This study investigates the relationship of urban thermal environment (UTE) with various influential factors as well as ecological conditions. The relation between LST and land use and land cover (LULC) changes was explored in terms of remote-sensing (RS) based indices; heat effect contribution index (HECI), Urban thermal field variance index (UTFVI), Surface urban heat island intensity (SUHII), Normal Difference Built-up Index (NDBI), and Normal Difference Vegetation Index (NDVI). LULC maps were classified using the unsupervised classification technique and made error matrix to determine the accuracy. Results revealed that the vegetated area in Faisalabad decreased by 230 km² due to an expansion in the urban area of 124-320 km² during the period 1992-2014. An average LST in the rural buffers is increasing rapidly as compare to urban buffer and varied over the eight years with a range of 0.68-2.57 (°C). After 2007, SUHII's linear trend was negative because rural temperatures were still rising. Based on HECI, we found that urban expansion mainly led to increase in LST. UTFVI has shown poor ecological conditions in all urban buffers. In addition, there is a positive correlation between LST and NDBI, while NDVI indicates a negative correlation with LST.

摘要

本研究调查了城市热环境（UTE）与各种影响因素以及生态条件之间的关系。研究了遥感与土地利用和土地覆盖（LULC）变化之间的关系，并以基于遥感（RS）的指标为依据。热效应贡献指数（HECI），城市热场方差指数（UTFVI），城市地表热岛强度（SUHII），正态差异累积指数（NDBI）和正态植被指数（NDVI）。使用无监督分类技术对LULC地图进行分类，并制作误差矩阵来确定准确性。结果表明，费萨拉巴德的植被减少了230  km ²，这是由于城市面积扩大了124-320  km ²在1992年至2014年期间。与城市缓冲区相比，农村缓冲区的平均LST迅速增加，并且在八年内变化范围为0.68-2.57（°C）。2007年之后，由于农村温度仍在上升，SUHII的线性趋势为负。基于HECI，我们发现城市扩张主要导致LST的增加。UTFVI在所有城市缓冲区都显示出恶劣的生态条件。此外，LST与NDBI之间存在正相关，而NDVI则与LST之间存在负相关。