期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2006
卷号：XXXVI Part 6
页码：97-101
出版社：Copernicus Publications
摘要：Potential evapotranspiration (PET) is an important parameter of water budgets at different spatial scales and is a critical variable for understanding regional biological processes. It is often an important variable in estimating actual evapotranspiration (AET) in rainfall-runoff and ecosystem modelling. However, PET is defined in different ways in the literature and quantitative estimation of PET with existing mathematical formulas produces inconsistent results. The objectives of this study are to contrast five commonly used PET methods and quantify the 10 days PET of selected 3 meteorological stations in the Mongolian grassland. The temperature based (Hargreaves-Samani), combination Penman-Monteith method (FAO56-PM), radiation based (Makkink, and Priestley-Taylor) and Mass transfer based (Dalton aerodynamic) PET methods are compared. Also we examined temporal responses of remotely sensed NDVI to evapotranspiration during a four years period (2001-2004). 10 days NDVI values for Mongolian grassland region were calculated using National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) NDVI images. The study found that PET values calculated from the five methods were correlated with correlation coefficient 0.60 to 1.0. However, showed that PET values from different methods were significantly different from each other. Greater differences were found among the Dalton aerodynamic PET method than other four PET methods. In general, the combination Penman-Monteith method (FAO56-PM) and Hargreaves-Samani method performed better than the other PET methods in the Mongolian grassland. Based on the criteria of availability of input data and correlations with ground measurement ET values, the Hargreaves-Samani and combination Penman-Monteith methods (FAO56-PM) are recommended for regional applications in the Mongolian grasslands
