[目的]研究不同土地利用类型的地表亮温变化规律.[方法]基于2008年的MODIS数据,以长三角为研究区,结合IGBP土地分类体系,计算地表亮温,总结规律,并对原因进行探讨.[结果]不同土地利用类型有其独特的亮温变化.白天亮温大小为草地、建筑用地＞农田、林地和荒地＞湿地和水体；夜间亮温大小为水体、湿地、荒地＞建筑用地、草地＞林地、农田.亮温全年呈现冬低夏高、春增秋减的趋势.夜间亮温更能反映地表热辐射特点.太阳辐射、混合像元、比热容、含水量等是导致不同地类亮温差异的主要原因.[结论]不同土地利用类型的亮温变化特点对于土壤含水量分析、土地利用动态监测等具有重要意义.%[Objective] The aim of this study is to investigate the surface brightness temperature variation of different land use types. [ Method] Based on MODIS data in 2008 and 1GBP land classification system, the surface brightness temperature in the Yangtze River Delta area was calculated, and its rules and reasons were also discussed in this study. [ Result] the Different land use types had its own special brightness temperature variation. During the day, the brightness temperature was as follows: grassland or urban and built-up land > cropland, forest land and barren > wetland and water. During the night, the brightness temperature was as follows: water, wetland and barren > grassland or urban and built-up land > forest land and cropland. Brightness temperature showed the trend of high in summer and low in winter or increasing in spring and decreasing in fall. The characteristics of surface thermal radiation could be reflected better by brightness temperature at night. Solar radiation, mixed pixel, heat capacity, water content were the main reasons for the difference of brightness temperature in different land types. [ Conclusion] The brightness temperature variation of different land use types has significance for water content analysis in soil and dynamic monitoring of land use.
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