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利用2010年4期MODIS影像,基于植被指数、地表比辐射率、大气透过率和星上亮度温度,采用分裂窗口算法,反演石羊河流域不同季节地表温度并对其进行验证.结果表明:石羊河流域四季地表温度变化明显,昼夜温差很大,其中,春季温度分布在-13.45～29.27℃之间;夏季温度分布在-3.75～56.29℃之间;秋季温度分布在-10.15～32.67℃之间;冬季温度分布在-17.15～12.75℃之间.从地表温度空间分布上看,在武威、民勤、古浪等绿洲地区地表热量丰富,水土和植被效应显著,热量呈圈状空间递减趋势;在下游地区腾格里沙漠和巴丹吉林沙漠地区夏季温度最高,祁连山东端的石羊河上游地区由于受常年积雪、河流、地表植被和海拔等因素影响地表温度较低.MODIS数据为宏观小流域热环境监测提供了新的途径,且将遥感数据和地表下垫面数据相结合能提高反演精度.
Based on MODIS images of April 2010, the surface temperature in different seasons of Shiyang River Basin was retrieved and validated by split-window algorithm based on vegetation index, surface emissivity, atmospheric transmittance and on-board brightness temperature. : The temperature in the four seasons of Shiyang River Basin is obviously changed, and the temperature difference between day and night is very big. Among them, the spring temperature distributes between -13.45 and 29.27 ℃; the summer temperature distributes between -3.75 and 56.29 ℃; the autumn temperature distributes between -10.15 and 32.67 ℃ in winter and the temperature in winter is between -17.15 and 12.75 ° C. From the spatial distribution of surface temperature, the surface heat in Wuwei, Minqin, Gulang and other oasis regions is rich in soil heat and vegetation, and the heat is in a circle In the lower reaches of the Tengger Desert and Badain Jaran Desert in summer, the summer temperature is the highest, while the upper reaches of the Shiyang River in the eastern Qilian Mountains have a lower surface temperature due to snowfall, rivers, surface vegetation and altitude, etc. MODIS data It provides a new way to monitor the thermal environment in the macroscopic small watershed, and combining the remote sensing data with the underlying surface data can improve the inversion accuracy.