SEBAL-based Sensible and Latent Heat Fluxes in ihe Irrigated Gediz Basin, Turkey

International Water Management Institute, P.O. Box 2075, Colombo, Sri Lanka
Journal of Hydrology (Impact Factor: 3.05). 03/2000; 229(1):87-100. DOI: 10.1016/S0022-1694(99)00202-4


Surface Energy Balance Algorithm for Land (SEBAL) is a relatively new parameterization of surface heat fluxes based on spectral satellite measurements. SEBAL requires spatially distributed, visible, near-infrared and thermal infrared data, which can be taken from Landsat Thematic Mapper. The SEBAL parameterization is an iterative and feedback-based numerical procedure that deduces the radiation, heat and evaporation fluxes. The sensible and latent heat fluxes across the lower Gediz River Basin in Western Turkey have been estimated. The energy balance during satellite overpass, and the integrated 24 h fluxes are computed on a pixel-by-pixel basis. The temporal variability in heat fluxes between June and August will be evaluated. The effect of irrigation on the partitioning of energy and crop water stress is discussed.

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Available from: W.G.M. Bastiaanssen
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    • "Therefore, ReSET can be used in estimating ET a at large scale, such as regional or river basin scales. More details on the procedure of how ET a can be estimated from satellite imagery are presented in Bastiaanssen et al. (1998b, 2002), Bastiaanssen (2000), Allen et al. (2005), and Tasumi et al. (2005). Clouds can affect calculations of the estimated ET a when using remote sensing. "
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    ABSTRACT: The objectives of this study are to: (i) estimate the actual evapotranspiration (ETa) of the different irrigated crops in the South Platte River Basin, Colorado, USA; (ii) compare the consumption use for the irrigated areas for 2001 and 2010; (iii) investigate the impact of irrigation system (flood/sprinkler) on the estimated ETa. The ReSET model, a surface energy balance remote sensing based model, is used in this study to estimate the ETa of the South Platte River Basin irrigated crops for 2001 and 2010. Landsat 5/7 satellite images, weather data, shape files of irrigated crops, and a digital elevation model (DEM) were acquired and processed for the study area. The results of this study show that the estimated ETa using the ReSET model showed a reduction of 7.1% from 2.51 × 109 m3 in 2001 to 2.33 × 109 m3 in 2010, mainly due to the reduction of the irrigated area from 2001 to 2010 by 6.6%. The estimated total ETa of crops irrigated with flood irrigation systems decreased from 66.1 to 54.6%, while the estimated total ETa of crops irrigated with sprinkler systems increased from 33.9 to 45.4%. For 2001, the average seasonal ETa of all crops for flood irrigation and sprinkler irrigation, respectively, were 665 and 712 mm, with a 7% greater ETa for sprinkler systems. The ReSET model ETa estimates have been validated in a previous study of lysimeter measurements. However, in this study and due to the unavailability of a lysimeter, the model ETa estimates were verified with the reference evapotranspiration (ETr) of the weather stations in the study area. The results of the t-test shows a p-value = 0.124, greater than 0.05, which indicates that the means of the ReSET ETa estimates and the ETr are not significantly different. Additionally, the results of the F-test shows a p-value = 0.674, greater than 0.05, which indicates that the two variances of the ReSET ETa estimates and the ETr are homogeneous
    Full-text · Article · Oct 2015 · Irrigation and Drainage
    • "It is comprised of evaporation and transpiration, and accounts for ∼60% of the total annual precipitation (Kite, 2000; Fisher et al., 2005). ET plays an important role in water and energy budgets in the surface-atmosphere processes and climate systems (Brutsaert, 1998; Bastiaanssen, 2000; Boegh et al., 2002). In addition, it is also strongly interrelated with the ecosystem productivity, flooding, and drought, and its precise estimation is necessary for efficient water resources management, the been conducted, and it is necessary to make comparisons with that of the ground-based measurements (i.e., Cheongmi and Sulma flux towers) as well as MODIS and Global Land Data Assimilation System (GLDAS) in multi temporal scale. "
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    ABSTRACT: Effective water use in the irrigated agriculture requires an accurate estimation of evapotranspiration (ET) to understand the interaction between land surface and the atmosphere. The operationally available polar orbit satellite datasets with low temporal resolutions have long been utilized for the estimation of ET from field to regional scale. However, geostationary satellites, which are continuously measuring several factors related to land surface and the atmosphere over large regional scales, have high temporal resolution compared to polar orbit satellites. Thus, in this study, we present a framework for estimating potential ET at three different temporal scales (instantaneous, 3-h and daily) using the Priestley–Taylor (ET PT) method with a new geostationary satellite, the Communication, Ocean, and Meteorological Satellite (COMS) dataset. The derived ET PT estimates were compared with ground based flux tower [Cheongmi (CFC) and Sulma (SMC)] measurements, with ET PT calculated from MODerate Resolution Imaging Spec-troradiometer (MODIS) and with ET PT calculated from Global Land Data Assimilation System (GLDAS) datasets during the growing seasons of 2011. The GLDAS ET PT were significantly overestimated compared to the flux tower ET PT (bias of 147.92 and 169.69 W m −2 at 3-h time scale and bias of 2.64 and 3.37 mm day −1 at daily time scale for SMC and CFC, respectively), while the COMS and MODIS ET PT were slightly underestimated (bias ranged from −15.31 to −55.65 W m −2 at instantaneous time scale and bias ranged from −0.04 to −1.03 mm day −1 at daily time scale for SMC and CFC, respectively). Based on the results, the COMS estimated ET PT was slightly more accurate than MODIS ET PT in comparison with the flux tower ET PT , yielding the index of agreement (IOA) between ∼0.89 and 0.96 for all time scale.
    No preview · Article · Sep 2015 · Agricultural Water Management
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    • "As a key factor in the water cycle, soil moisture is closely associated with precipitation and evapotranspiration, which include mainly plant transpiration and bare soil evaporation [Hohenegger et al., 2009; Wetzel and Chang, 1987]. It also takes part in the energy cycle by changing soil thermal parameters and surface albedo [Nakshabandi and Kohnke, 1965; Teuling and Seneviratne, 2008], via its impact on the partitioning of incoming energy into latent and sensible heat fluxes [Bastiaanssen, 2000]. Furthermore, soil moisture strongly interacts with the biosphere by affecting the terrestrial carbon exchange and nitrogen cycle [Fierer and Schimel, 2002; Granier et al., 2007]. "
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    ABSTRACT: The variability of soil moisture over East Asia was analyzed using a long-term data set from the Global Land Data Assimilation System (GLDAS). Overall, a clear decreasing trend occurred over a period of 63 years, with pronounced drying over Northeast China, North China, part of Mongolia, and Russia near Lake Baikal. Statistical analyses show that decreasing precipitation and global warming have different effects on the decrease in soil moisture. The qualitative analysis and quantitative contributions illustrated that soil drying is driven primarily by decreasing precipitation, and is enhanced almost twofold by increasing temperatures. As soil moisture decreases, the positive feedback between soil moisture and temperature may result in future water shortages. Following the Representative Concentration Pathways 8.5 (RCP8.5) and 4.5 (RCP4.5) simulation scenario of Coupled Model Intercomparison Project phase 5 (CMIP5), the model-predicted soil moisture demonstrated a continuously decreasing trend during the twenty-first century.
    Full-text · Article · Jun 2015
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