Publications

Zhu, WB; Lv, AF; Jia, SF; Yan, JB (2017). A New Contextual Parameterization of Evaporative Fraction to Reduce the Reliance of the T-s - VI Triangle Method on the Dry Edge. REMOTE SENSING, 9(1), 26.

Abstract
In this study, a new parameterization scheme of evaporative fraction (EF) was developed from the contextual information of remotely sensed radiative surface temperature (T-s) and vegetation index (VI). In the traditional T-s VI triangle methods, the Priestley-Taylor parameter circle divide of each pixel was interpolated for each VI interval; in our proposed new parameterization scheme (NPS), it was performed for each isopiestic line of soil surface moisture. Specifically, circle divide of mixed pixels was determined as the weighted-average value of bare soil circle divide and full-cover vegetation circle divide. The maximum T-s of bare soil (T-smax) is the sole parameter needed as the constraint of the dry edge. This has not only bypassed the task involved in the determination of the maximum T-s of fully vegetated surface (T-cmax), but also made it possible to reduce the reliance of the T-s - VI triangle methods on the determination of the dry edge. Ground-based measuremen T-s taken during 21 days in 2004 were used to validate the EF retrievals. Results show that the accuracy achieved by the NPS is comparable to that achieved by the traditional T-s - VI triangle methods. Therefore, the simplicity of the proposed new parameterization scheme does not compromise its accuracy in monitoring EF.

DOI:
10.3390/rs9010026

ISSN:
2072-4292