关键词: HASM, 潜在蒸发, 插值, 黑河流域

Abstract:

Potential Evapotranspiration (PET) is one of the important factors in the study of evapotranspiration (ET) and local water resources. Accurate PET dataset is crucial for improving our understanding of basin-scale hydrology, agriculture and earth sciences. In this study, ET data measured at 12 stations during the period of 2000-2009 were used to simulate the PET in Heihe River Basin by using a new surface modeling method, so called High Accuracy and high Speed Method (HASM), which has been successfully used in the construction of Digital Elevation Model (DEM) and the studies of ecosystem changes. The relationship between PET and climatically/topographical variables was explored, and a polynomial regression model for PET was developed. The stepwise regression method was used to find an optimal subset of influence factors for PET. Finally, polynomial regression and residual interpolation using HASM were employed to develop a gridded ET dataset for Heihe River Basin. The simulation results of our method were compared with other potential evapotranspiration datasets including the "Simulated forcing dataset of 3km/6 hour in 1980-2010 in Heihe River Basin" and the interpolation results by using Kriging, IDW and Spline. Results showed that HASM exhibited good performance in ET simulation. Accuracy tests revealed that HASM was superior to other datasets. Therefore, HASM can be considered as an alternative and accurate method for PET interpolation in Heihe River Basin. As the basic geographical data, PET produced by HASM can be used for other applications.

Key words: HASM, PET, interpolation, Heihe River Basin