摘要
【目的】定量分析喀斯特城市桂林1990—2015年快速扩展对热环境的影响。【方法】提出喀斯特山峰混合像元比辐射率估算方法,对Landsat卫星12景遥感图像用模型反演地表温度并分析地表温度时空变化规律;提出建筑覆盖率、水体覆盖率和裸土率估算方法,反演植被覆盖度、建筑覆盖率、水体覆盖率、裸土率和裸岩率,分析混合像元中各地物覆盖率变化对地表温度的影响。【结果】1)研究地的建筑/道路、喀斯特山峰裸岩、干燥裸土的地表温度相对较高,水体和茂密植被覆盖的喀斯特山峰阴坡地表温度最低,茂密植被覆盖的喀斯特山峰阳坡的地表温度也相对较低;在太阳辐射下,喀斯特山峰阳坡地表温度比阴坡地表温度高1~3℃。2)1990—2015年研究地的地表温度高于喀斯特山峰茂密林地的高温像元比例呈逐渐上升的趋势,由61.9%变化到75.2%。3)研究地的地表温度因植被覆盖度、水体覆盖率增加0.1而分别降低0.5~0.7℃,0.2~0.4℃;因建筑覆盖率、裸土率和裸岩率增加0.1而分别升高0.4~0.7℃,0.4~0.6℃和0.3~0.5℃。【结论】喀斯特城市桂林的地表温度明显受人为因素、植被覆盖和地形的影响。
[Purposes]The impact of urban rapid expansion on thermal environment needs to be analyzed in Guilin,a karst city,from1990 to 2015.[Methods]The temporal and spatial changes of land surface temperature（LST）were derived from 12 Landsat images with the proposal of the emissivity estimation method in the mixed pixels on karst hills.Then the derived affecting factors on LST,including vegetation coverage,building percentage,water percentage,bare rock percentage and bare soil percentage,was analyzed.[Findings]1）LSTs in the study area of buildings,roads,dry soil and bare rocks on sunny karst slopes are highest,while LSTs of water body and dense vegetation on shady karst slopes are lowest.LSTs of dense vegetation on sunny karst slopes also are very low.LSTs of sunny karst slopes are 1~3℃ higher than those of shady karst slopes under solar radiation.2）The percentage of high temperature pixels which are defined as their LST above that of dense forest on the karst hills shows an upward trend from 61.9% to75.2% during 1990~2015 in the study area.3）LSTs decreases respectively from 0.5℃to 0.7℃,from 0.2℃to 0.4℃ with 0.1 increasing of vegetation and water body percentages,and increases respectively from 0.4℃to 0.7℃,from 0.4℃to 0.6℃,from0.3℃to 0.5℃ with 0.1 increasing of building,bare soil and bare rock percentages in the study area.[Conclusions]LSTs are influenced by human,vegetation coverage and terrain in Guilin.
作者
王恺宁
王修信
WANG Kaining;WANG Xiuxin(School of Urban and Environmental Sciences,Liaoning Normal University,Dalian Liaoning 116029;College of Computer Science and Information Technology,Guangxi Normal University,Guilin Guangxi 54100;State key Laboratory of Remote Sensing Science,Beijing Normal University,Beijing 100875,China)
出处
《重庆师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第4期117-124,共8页
Journal of Chongqing Normal University:Natural Science
基金
国家自然科学基金地区科学基金项目(No.41561008)
广西自然科学基金(No.2014GXNSFAA118289)
广西高校科学技术研究项目(No.2013LX020
No.KY2015LX007)
关键词
喀斯特城市
遥感
地表温度
时空变化
地物覆盖影响
桂林
karst city
remote sensing
land surface temperature
temporal and spatial changes
land cover influence
Guilin
