干旱区典型绿洲地表温度昼夜变化特征研究——以于田绿洲为例

Diurnal variation of land surface temperature in Keriya Oasis: A typical arid land oasis

文中利用2012年长时间序列MODIS地表温度产品,以于田绿洲为例进行干旱区地表昼夜温差时间和空间变化特征的研究。结合MODIS土地利用数据,进一步分析了不同土地利用类型下地表昼夜温差的长时序变化特征。结果显示:研究区绿洲地表昼夜温差在0-40℃之间,其年均值小于25℃,而对于地表昼夜温差范围在0-60℃荒漠区其年均值大于25℃;并且绿洲-荒漠交错带呈现出明显的锯齿状效应。不同土地利用类型的地表昼夜温差值的大小依次是未利用土地、林地、草地、耕地及建设用地。尽管土地利用类型对地表昼夜温差有较大影响,但是其时间序列变化特征并未受到土地利用类型的明显影响;不同土地利用类型具有相似的地表昼夜温差时序特征。相比于Terra卫星,Aqua卫星观测数据能够更好的反映地表昼夜温差的变化特征。

In the research,the temporal and spatial diurnal variations of land surface temperature（LST） in Keriya Oasis were studied by using the long time series of the Moderate Resolution Imaging Spectro-radiometer（MODIS） LST products. The spatial distributions of LST and the diurnal distribution of LST were systematically analyzed in 2012 using the annual average value. Combined with the 2012 MODIS land use data,the long time series temporal diurnal variations of LST were also analyzed for different land use types. Results have shown that the cold island effect of oasis was obviously observed by Terra and Aqua MODIS and the diurnal LST was significantly different between oasis and desert. The diurnal LST value at the range of 0-60℃ in oasis area was less than 25℃,while the diurnal LST value in desert area at the range of 0-60℃ was larger than the temperature.The diurnal LST values of different land use types from high to low were unutilized land,forest land,grassland,cultivated land and the construction land respectively. Although land use types had a great impact on the diurnal variations of LST,the temporal variations of diurnal LST were not significantly affected by land use types,and the different land use types had the similar temporal variations of diurnal LST. Compared with the Terra satellite,the observation data of Aqua satellite can better reflect the temporal variations of diurnal LST for different land use types as the drastic changes of diurnal LST can observed by Aqua satellite.