中文摘要：

对珠江三角洲六类主要林分（区域）的蒸散发比进行了研究，6类林分包括桉树林、果树林、针阔混交林、灌木林、针叶、混交林、阔叶混交林。同时对基于 Priestley-Taylor扩展模型的物理机制进行分析与推理，发现可以通过 MODIS和 TM热红外数据计算的地温值来评估较大区域上的蒸散发能力，并结合2008~2009年的晴空数据进行计算分析。结果表明珠三角6类林分（区域）的蒸散发作用相当，桉树林并非耗水量最大的林种。

英文摘要：

Evapotranspiration ratio of six major forest types in the Pearl River Delta was studied in this paper, and the six forest types included eucalyptus forest, fruit forest, coniferous forest, shrub forest, coniferous forest, and broad-leaved mixed for- est. The mechanism of PT-T model was analyzed based on Priestley-Taylor ex- tended model, and the result showed that land surface temperature or temperature difference between day and night could be used to evaluate the evapotranspiration factor. The evapotranspiration of 6 forest types was estimated with MODIS data and TM data and weather information during 2008-2009. The result suggested that water consumption of different forest differs insignificantly, and the EF of eucalyptus is not high.