Validation of Global Evapotranspiration Product (MOD16) using Flux Tower Data in the African Savanna, South Africa

Remote Sensing

Abel Ramoelo¹  Nobuhle Majozi¹  Renaud Mathieu¹  Nebo Jovanovic¹  Alecia Nickless¹ 

[1] Natural Resource and Environment, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa; E-Mails:

关键词: evapotranspiration;    MOD16;    eddy covariance;    flux tower;    Penman-Monteith;   

DOI  :  10.3390/rs6087406

来源: mdpi

【 摘 要 】

Globally, water is an important resource required for the survival of human beings. Water is a scarce resource in the semi-arid environments, including South Africa. In South Africa, several studies have quantified evapotranspiration (ET) in different ecosystems at a local scale. Accurate spatially explicit information on ET is rare in the country mainly due to lack of appropriate tools. In recent years, a remote sensing ET product from the MODerate Resolution Imaging Spectrometer (MOD16) has been developed. However, its accuracy is not known in South African ecosystems. The objective of this study was to validate the MOD16 ET product using data from two eddy covariance flux towers, namely; Skukuza and Malopeni installed in a savanna and woodland ecosystem within the Kruger National Park, South Africa. Eight day cumulative ET data from the flux towers was calculated to coincide with the eight day MOD16 products over a period of 10 years from 2000 to 2010. The Skukuza flux tower results showed inconsistent comparisons with MOD16 ET. The Malopeni site achieved a poorer comparison with MOD16 ET compared to the Skukuza, and due to a shorter measurement period, data validation was performed for 2009 only. The inconsistent comparison of MOD16 and flux tower-based ET can be attributed to, among other things, the parameterization of the Penman-Monteith model, flux tower measurement errors, and flux tower footprint vs. MODIS pixel. MOD16 is important for global inference of ET, but for use in South Africa’s integrated water management, a locally parameterized and improved product should be developed.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland