【摘要】 随着城市化进程逐步加快，城市热岛问题严峻。探究合肥市区城市化空间分布特征与热贡献度，对缓解城市热岛加剧具有重要的理论意义。选取四期Landsat遥感影像，在Google Earth Engine(GEE)平台上利用随机森林结合三指数法对合肥市主城区1987,2000,2010和2020年的遥感数据进行土地利用分类，运用地图编码提取城市化变化轨迹，并采用单窗算法进行地表温度反演，以热贡献度法分析城市化轨迹对地表温度变化特征的影响。结果表明：(1)自1987到2020年期间，合肥市区的建设用地面积扩大了近4倍，由7.9%扩大至30.1%,耕地面积大幅度减少，由38.6%减少至18.4%。(2)33年的城市化发展，合肥市区的地表温度增温区面积的增幅为40.1%,降温区的涨幅为0.8%,地表热环境总体呈现升温趋势。(3)本研究共提取土地利用变化轨迹617条，其中城市化相关轨迹86条，选取前10条城市化轨迹分析得出合肥市区建设用地主要来自于耕地和未利用地，主要分布在城市中心周边地区及位于合肥市区东部的蜀山区。(4)合肥市33a城市化轨迹对地表温度贡献变化中，未利用地转化为建设用地贡献度增幅最高，耕地其次。更多还原

【Abstract】 With the gradual acceleration of urbanization, the problem of urban heat island is serious.To explore the spatial distribution characteristics and thermal contribution of urbanization in Hefei has important theoretical significance for alleviating the intensification of urban heat island.Four Landsat remote sensing images were selected to classify land use using random forest combined with three index method on Google Earth Engine(GEE) platform for the main urban area of Hefei city in 1987,2000,2010 and 2020.The urbanization change trajectory was extracted by map coding.The single-window algorithm is used to invert land surface temperature(LST) and the thermal contribution method is used to analyze the change characteristics of LST caused by urbanization trajectory.The results show that:(1) from 1987 to 2020,the area of construction land in Hefei urban area increased by nearly 4 times, from 7.9% to 30.1%,and the area of cultivated land decreased significantly, from 38.6% to 18.4%;(2) With the urbanization development in 33 a, the increase of surface temperature area in urban area of Hefei is 40.1%,and the increase of cooling area is 0.8%.The overall surface thermal environment shows a warming trend.(3) A total of 617 land use change tracks were extracted in this study, including 86 tracks related to urbanization.The analysis of the top 10 urbanization tracks shows that the construction land in Hefei urban area mainly comes from the conversion of cultivated land and unused land, which is mainly distributed in the surrounding areas of the urban center and shushan district located in the eastern part.(4) The contribution of unused land to construction land has the highest increase, followed by cultivated land.更多还原