scholarly journals The LAB-Net Soil Moisture Network: Application to Thermal Remote Sensing and Surface Energy Balance

Data ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 6 ◽  
Author(s):  
Cristian Mattar ◽  
Andrés Santamaría-Artigas ◽  
Claudio Durán-Alarcón ◽  
Luis Olivera-Guerra ◽  
Rodrigo Fuster ◽  
...  
Author(s):  
G. Boulet ◽  
E. Delogu ◽  
W. Chebbi ◽  
Z. Rafi ◽  
V. Le Dantec ◽  
...  

<p><strong>Abstract.</strong> Evapotranspiration is an important component of the water cycle. For the agronomic management and ecosystem health monitoring, it is also important to provide an estimate of evapotranspiration components, i.e. transpiration and soil evaporation. To do so, Thermal InfraRed data can be used with dual-source surface energy balance models, because they solve separate energy budgets for the soil and the vegetation. But those models rely on specific assumptions on raw levels of plant water stress to get both components (evaporation and transpiration) out of a single source of information, namely the surface temperature. Additional information from remote sensing data are thus required. This works evaluates the ability of the SPARSE dual-source energy balance model to compute not only total evapotranspiration, but also water stress and transpiration/evaporation components, using either the sole surface temperature as a remote sensing driver, or a combination of surface temperature and soil moisture level derived from microwave data. Flux data at an experimental plot in semi-arid Morocco is used to assess this potentiality and shows the increased robustness of both the total evapotranspiration and partitioning retrieval performances. This work is realized within the frame of the Phase A activities for the TRISHNA CNES/ISRO Thermal Infra-Red satellite mission.</p>


2021 ◽  
Vol 58 (03) ◽  
pp. 274-285
Author(s):  
H. V. Parmar ◽  
N. K. Gontia

Remote sensing based various land surface and bio-physical variables like Normalized Difference Vegetation Index (NDVI), Land Surface Temperature (LST), surface albedo, transmittance and surface emissivity are useful for the estimation of spatio-temporal variations in evapotranspiration (ET) using Surface Energy Balance Algorithm for Land (SEBAL) method. These variables were estimated under the present study for Ozat-II canal command in Junagadh district, Gujarat, India, using Landsat-7 and Landsat-8 images of summer season of years 2014 and 2015. The derived parameters were used in SEBAL to estimate the Actual Evapotranspiration (AET) of groundnut and sesame crops. The lower values NDVI observed during initial (March) and end (May) stages of crop growth indicated low vegetation cover during these periods. With full canopy coverage of the crops, higher value of NDVI (0.90) was observed during the mid-crop growth stage. The remote sensing-based LST was lower for agricultural areas and the area near banks of the canal and Ozat River, while higher surface temperatures were observed for rural settlements, road and areas with exposed dry soil. The maximum surface temperatures in the cropland were observed as 311.0 K during March 25, 2014 and 315.8 K during May 31, 2015. The AET of summer groundnut increased from 3.75 to 7.38 mm.day-1, and then decreased to 3.99 mm.day-1 towards the end stage of crop growth. The daily AET of summer sesame ranged from 1.06 to 7.72 mm.day-1 over different crop growth stages. The seasonal AET of groundnut and sesame worked out to 358.19 mm and 346.31 mm, respectively. The estimated AET would be helpful to schedule irrigation in the large canal command.


2020 ◽  
pp. 1-19
Author(s):  
Manish K. Nema ◽  
Hitesh P. Thakur ◽  
Hitesh Upreti ◽  
Sanjay K. Jain ◽  
P. K. Mishra ◽  
...  

1998 ◽  
Vol 212-213 ◽  
pp. 213-229 ◽  
Author(s):  
W.G.M. Bastiaanssen ◽  
H. Pelgrum ◽  
J. Wang ◽  
Y. Ma ◽  
J.F. Moreno ◽  
...  

2005 ◽  
Author(s):  
F.G. Hall ◽  
D.E. Strebel ◽  
P.J. Sellers ◽  
K.F. Huemmrich ◽  
S.J. Goetz

2015 ◽  
Vol 12 (5) ◽  
pp. 4631-4675
Author(s):  
T. Gerken ◽  
W. Babel ◽  
M. Herzog ◽  
K. Fuchs ◽  
F. Sun ◽  
...  

Abstract. The Tibetan Plateau plays a significant role in the atmospheric circulation and the Asian monsoon system. Turbulent surface fluxes and the evolution of boundary layer clouds to deep and moist convection provide a feedback system that modifies the Plateau's surface energy balance on scales that are currently unresolved in mesoscale models. This work analyses the land surface's role and specifically the influence of soil moisture on the triggering of convection at a cross-section of the Nam Co Lake basin, 150 km north of Lhasa using a cloud resolving atmospheric model with a fully coupled surface. The modelled turbulent fluxes and development of convection compare reasonably well with the observed weather. The simulations span Bowen-ratios of 0.5 to 2.5. It is found that convection development is strongest at intermediate soil moistures. Dry cases with soils close to the permanent wilting point are moisture limited in the convection development, while convection in wet soil moisture cases is limited by cloud cover reducing incoming solar radiation and sensible heat fluxes. This has a strong impact on the surface energy balance. This study also shows that local development of convection is an important mechanism for the upward transport of water vapour that originates from the lake basin that can then be transported to dryer regions of the plateau. Both processes demonstrate the importance of soil moisture and surface–atmosphere interactions on the energy and hydrological cycles of the Tibetan Plateau.


2010 ◽  
Vol 7 (4) ◽  
pp. 4875-4924 ◽  
Author(s):  
Z. Q. Gao ◽  
C. S. Liu ◽  
W. Gao ◽  
N. B. Chang

Abstract. Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spatial scales. This paper extends the existing modeling efforts with the inclusion of new components for ET estimation at varying temporal and spatial scales under complex terrain. Following a coupled remote sensing and surface energy balance approach, this study emphasizes the structure and function of the Surface Energy Balance with Topography Algorithm (SEBTA). With the aid of the elevation and landscape information, such as slope and aspect parameters derived from the digital elevation model (DEM), and the vegetation cover derived from satellite images, the SEBTA can fully account for the dynamic impacts of complex terrain and changing land cover in concert with some varying kinetic parameters (i.e., roughness and zero-plane displacement) over time. Besides, the dry and wet pixels can be recognized automatically and dynamically in image processing thereby making the SEBTA more sensitive to derive the sensible heat flux for ET estimation. To prove the application potential, the SEBTA was carried out to present the robust estimates of 24 h solar radiation over time, which leads to the smooth simulation of the ET over seasons in northern China where the regional climate and vegetation cover in different seasons compound the ET calculations. The SEBTA was validated by the measured data at the ground level. During validation, it shows that the consistency index reached 0.92 and the correlation coefficient was 0.87.


Author(s):  
Mulugeta Genanu ◽  
Tena Alamirew ◽  
Gabriel Senay ◽  
Mekonnen Gebremichael

Remote sensing datasets are increasingly being used to provide spatially explicit large scale evapotranspiration (ET) estimates. The focus of this study was to estimate and thematically map on a pixel-by-pixel basis, the actual evapotranspiration (ETa) of the Wonji Shoa Sugarcane Estate using the Surface Energy Balance Algorithm for Land (SEBAL), Simplified Surface Energy Balance (SSEB) and Operational Simplified Surface Energy Balance (SSEBop) algorithms. The results obtained revealed that the ranges of the daily ETa estimated on January 25, February 26, September 06 and October 08, 2002 using SEBAL were 0.0 - 6.85, 0.0 &ndash; 9.36, 0.0 &ndash; 3.61, 0.0 &ndash; 6.83 mm/day; using SSEB 0.0 - 6.78, 0.0 &ndash; 7.81, 0.0 &ndash; 3.65, 0.0 &ndash; 6.46 mm/day, and SSEBop were 0.05 - 8.25, 0.0 &ndash; 8.82, 0.2 &ndash; 4.0, 0.0 &ndash; 7.40 mm/day, respectively. The Root Mean Square Error (RMSE) values between SSEB and SEBAL, SSEBop and SEBAL, and SSEB and SSEBop were 0.548, 0.548, and 0.99 for January 25, 2002; 0.739, 0.753, and 0.994 for February 26, 2002;0.847, 0.846, and 0.999 for September 06, 2002; 0.573, 0.573, and 1.00 for October 08, 2002, respectively. The standard deviation of ETa over the sugarcane estate showed high spatio-temporal variability perhaps due to soil moisture variability and surface cover. The three algorithm results showed that well watered sugarcane fields in the mid-season growing stage of the crop had higher ETa values compared with the other dry agricultural fields confirming that they consumptively use more water. Generally during the dry season, ETa is limited to water surplus areas only and in wet season, ETa was high throughout the entire sugarcane estate. The evaporation fraction (ETrF) results also followed the same pattern as the daily ETa over the sugarcane estate. The total crop and irrigation water requirement and effective rainfall estimated using the Cropwat model were 2468.8, 2061.6 and 423.8 mm/yr for January 2001 planted and 2281.9, 1851.0 and 437.8 mm/yr for March 2001 planted sugarcanes, respectively. The mean annual ETa estimated for the whole estate were 107 Mm3, 140 Mm3, and 178 Mm3 using SEBAL, SSEB, and SSEBop, respectively. Even though the algorithms should be validated through field observation, they have potential to be used for effective estimation of ET in the sugarcane estate.


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