Majozi, Nobuhle PMannaerts, CMRamoelo, AbelMathieu, Renaud SAMudau, Azwitamisi EVerhoef, W2018-05-232018-05-232017-03Majozi, N.P., Mannaerts, C.M., Ramoelo, A,. Mathieu, R.S.A,. Mudau, Azwitamisi E. and Verhoef, W. 2017. An intercomparison of satellite-based daily evapotranspiration estimates under different eco-climatic regions in South Africa. Remote Sensing, vol 9(4)307, pp 1-212072-4292http://www.mdpi.com/2072-4292/9/4/307http://hdl.handle.net/10204/10232Copyright: 2017. MDPIKnowledge of evapotranspiration (ET) is essential for enhancing our understanding of the hydrological cycle, as well as for managing water resources, particularly in semi-arid regions. Remote sensing offers a comprehensive means of monitoring this phenomenon at different spatial and temporal intervals. Currently, several satellite methods exist and are used to assess ET at various spatial and temporal resolutions with various degrees of accuracy and precision. This research investigated the performance of three satellite-based ET algorithms and two global products, namely land surface temperature/vegetation index (TsVI), Penman–Monteith (PM), and the Meteosat Second Generation ET (MET) and the Global Land-surface Evaporation: the Amsterdam Methodology (GLEAM) global products, in two eco-regions of South Africa. Daily ET derived from the eddy covariance system from Skukuza, a sub-tropical, savanna biome, and large aperture boundary layer scintillometer system in Elandsberg, a Mediterranean, fynbos biome, during the dry and wet seasons, were used to evaluate the models. Low coefficients of determination (R2) of between 0 and 0.45 were recorded on both sites, during both seasons. Although PM performed best during periods of high ET at both sites, results show it was outperformed by other models during low ET times. TsVI and MET were similarly accurate in the dry season in Skukuza, as GLEAM was the most accurate in Elandsberg during the wet season. The conclusion is that none of the models performed well, as shown by low R2 and high errors in all the models. In essence, our results conclude that further investigation of the PM model is possible to improve its estimation of low ET measurements.enEddy covarianceEvapotranspirationLarge aperture boundary layer scintillometerLatent heat fluxRemote sensingArticleMajozi, N. P., Mannaerts, C., Ramoelo, A., Mathieu, R. S., Mudau, A. E., & Verhoef, W. (2017). An intercomparison of satellite-based daily evapotranspiration estimates under different eco-climatic regions in South Africa. http://hdl.handle.net/10204/10232Majozi, Nobuhle P, CM Mannaerts, Abel Ramoelo, Renaud SA Mathieu, Azwitamisi E Mudau, and W Verhoef "An intercomparison of satellite-based daily evapotranspiration estimates under different eco-climatic regions in South Africa." (2017) http://hdl.handle.net/10204/10232Majozi NP, Mannaerts C, Ramoelo A, Mathieu RS, Mudau AE, Verhoef W. An intercomparison of satellite-based daily evapotranspiration estimates under different eco-climatic regions in South Africa. 2017; http://hdl.handle.net/10204/10232.TY - Article AU - Majozi, Nobuhle P AU - Mannaerts, CM AU - Ramoelo, Abel AU - Mathieu, Renaud SA AU - Mudau, Azwitamisi E AU - Verhoef, W AB - Knowledge of evapotranspiration (ET) is essential for enhancing our understanding of the hydrological cycle, as well as for managing water resources, particularly in semi-arid regions. Remote sensing offers a comprehensive means of monitoring this phenomenon at different spatial and temporal intervals. Currently, several satellite methods exist and are used to assess ET at various spatial and temporal resolutions with various degrees of accuracy and precision. This research investigated the performance of three satellite-based ET algorithms and two global products, namely land surface temperature/vegetation index (TsVI), Penman–Monteith (PM), and the Meteosat Second Generation ET (MET) and the Global Land-surface Evaporation: the Amsterdam Methodology (GLEAM) global products, in two eco-regions of South Africa. Daily ET derived from the eddy covariance system from Skukuza, a sub-tropical, savanna biome, and large aperture boundary layer scintillometer system in Elandsberg, a Mediterranean, fynbos biome, during the dry and wet seasons, were used to evaluate the models. Low coefficients of determination (R2) of between 0 and 0.45 were recorded on both sites, during both seasons. Although PM performed best during periods of high ET at both sites, results show it was outperformed by other models during low ET times. TsVI and MET were similarly accurate in the dry season in Skukuza, as GLEAM was the most accurate in Elandsberg during the wet season. The conclusion is that none of the models performed well, as shown by low R2 and high errors in all the models. In essence, our results conclude that further investigation of the PM model is possible to improve its estimation of low ET measurements. DA - 2017-03 DB - ResearchSpace DP - CSIR KW - Eddy covariance KW - Evapotranspiration KW - Large aperture boundary layer scintillometer KW - Latent heat flux KW - Remote sensing LK - https://researchspace.csir.co.za PY - 2017 SM - 2072-4292 T1 - An intercomparison of satellite-based daily evapotranspiration estimates under different eco-climatic regions in South Africa TI - An intercomparison of satellite-based daily evapotranspiration estimates under different eco-climatic regions in South Africa UR - http://hdl.handle.net/10204/10232 ER -