南宁市热岛效应的遥感研究

Remote Sensing Research of Heat Island Effect in Nanning

利用MODIS数据、TM数据对南宁市的地表温度、植被覆盖度、热场强度、热岛强度分别进行计算,从热岛的时空分布、热岛强度与面积、热岛成因三方面讨论南宁热岛特征及近十年的演变,研究南宁市热岛与高温天数的关系,建立了植被覆盖度与热场强度的联系。结果表明:南宁市从2000年的单一热岛中心逐渐发展成为多热岛中心;热岛面积以年均15.7%的速率增长,与之对应的是南宁市的高温天数平均以每年1.1 d的速率增长。尽管南宁市的植被对热岛的缓解作用强于城市用地及裸土的增温作用,但由于南宁市植被覆盖的面积(26.44%)远小于城市用地的面积(55.33%),城市热岛仍处于发展的状态。

The surface temperature,vegetation coverage,thermal field intensity and heat island intensity in Nanning are respectively calculated with MODIS and TM data.And the characteristics and evolution of heat island in Nanning in recent ten years are discussed from three aspects which are spatial and temporal distribution,intensi-ty and area,the factors of formation of heat island.Then the relations between heat island and days of high temper-ature are researched and the relations between vegetation coverage and thermal field intensity were built.The re-sults show that the single center of heat island in Nanning has become multi-centers since 2000;the heat island are-a has grown at an annual average rate of 15.7%,and corresponding days of high temperature has increased at an annual average rate of 1.1 days.Though the alleviation efficiency of the vegetation for heat island in Nanning is higher than calescence efficiency of the urban and bare land,the urban heat island is still in a developmental state as the area of vegetation coverage （26.44%）in Nanning is much smaller than the urban land′s （53.33%）.