利用单窗算法反演喀斯特城市地表温度

Land Surface Temperature Retrieval with Mono-window Algorithm in Karst City

针对桂林喀斯特城市快速扩展呈现的热岛问题，提出喀斯特山峰混合像元比辐射率估算方法，使单窗算法适用于喀斯特城市地表温度遥感反演。结果表明，地表温度反演值与测量值的误差在2。C内；桂林中心老城区的地表温度相对低于新开发区和城市南北部工厂区，地表温度随植被覆盖度的增加而降低，呈明显的负相关关系；水体的表面温度最低，约17。C，植被覆盖度较高的喀斯特山峰的地表温度较低，阴坡为18～19℃，而阳坡为22～24℃；水泥广场、大面积建筑区的地表温度较高，为32～35℃；厂房密集且生产过程释放热量的工厂的地表温度最高，为33～36℃，个别像元达到40℃。植被覆盖的喀斯特山峰呈现显著的城市凉岛现象，对调节喀斯特城市气候环境具有重要作用。

Urban heat island effect could be felt with in karst city,Guilin rapid expansion. After the mixed pixel emissivity of karst hills is computed,land surface temperature （LST） of the karst city could be retrieve from remote sensing image with mono-window algorithm in. Results demonstrated that the difference between the retrieved LST and measured LST is within 2 ℃. LST values in the old central district are lower than those in the developing district and industrial districts. LST possesses a negative correlation with vegetation fraction as it decreases with vegetation fraction increasing. LST of water is the mini- mum,about 17℃. As the karst hills are vegetated,LST of the shaded slope ranges from 18 to 19 ℃ and LST of sunlit slope from 22 to 24 ℃. However,the LST range of concrete squares and large buildings is from 32 to 33 ℃. As factories with the crowded buildings emit much heat,their LST values range from 33 to 36 ℃,the maximum. LST values of some pixels even reach 40℃. The vegetated karst hills show the urban cool island effect and can improve urban microclimate environment in the karst cities.