沙河流域地表通量的定量遥感估算

LAND SURFACE HEAT FLUXES IN THE SHAHE RIVER BASIN DERIVED FROM REMOTE SENSING DATA

地表通量遥感估算对植物长势监测、灾害监测和地区能量水循环研究具有重要的现实意义.本文选取北京市沙河流域2002-10-16和2003-04-07LandSat TM影像反演研究区春秋季地表特征参数和地表通量,结合地面观测资料,利用二层遥感模型对该地区的植被、土壤地表通量分别进行了遥感估算.结果表明,研究区地表能量平衡各分量具有明显的时空特征.春、秋季晴日植被通量和土壤通量的估算结果空间分布态势保持一致,植被通量略大于土壤分量,土壤通量的空间分异性更明显.

Land surface heat fluxes derived from remote sensing data are very important for monitoring plant growth,assessing crop yield,monitoring disasters and understanding of energy and water cycle in river basins as well as surrounding regions.In this study,LandSat TM data were applied to retrieve land surface characteristic parameters and land surface heat fluxes in the Shahe River basin,Beijing.Satellite images taken on 7 April,2003 and 16 October,2002 were selected as representative cases for spring and autumn.Based on land surface characteristic parameters and ground observation data,the land surface heat fluxes were estimated by applying a two-layer remote sensing ET model to estimate the fluxes of soil and vegetation,respectively.Data showed that the energy balance components had clear spatial-temporal characteristics.It was found that soil fluxes and vegetation fluxes had rather similar spatial distribution trends in spring and autumn.Vegetation components of the fluxes were slightly larger than soil ones,while soil components had a more obvious spatial variation.