Tan, S; Wu, BF; Yan, NN (2019). A method for downscaling daily evapotranspiration based on 30-m surface resistance. JOURNAL OF HYDROLOGY, 577, UNSP 123882.
Abstract
This study proposes a new method for downscaling actual evapotranspiration from resolution of 1-km to 30-m. The disaggregation approach is performed using the Jarvis model to simulate surface resistance, which describes the restriction of vapor from land surface, in the water exchange process without using land surface temperature data. The integrated surface resistance model, which takes climate indicators and canopy conditions into account, is primarily validated using in situ observations and employed in the downscaling model with considerable accuracy covering an entire growing season (April-October) in Zhangye Oasis. Good performance and good agreements between daily downscaled results and flux records from an EC (Eddy Covariance) tower have been obtained. The coefficient of determination (R-2) ranges from 0.80 to 0.91, and the mean bias (MB) ranges from 0.17 to 0.72. The vegetation growth process is also captured well by the downscaled results. The proposed method in this research performs better than downscaling approach based on land surface temperature. The accurate validation results and detailed spatial patterns suggest that the proposed downscaling strategy is reliable for water resource management.
DOI:
10.1016/j.jhydrol.2019.06.054
ISSN:
0022-1694