scholarly journals Application of the surface layer energy balance model for calculating of the evaporation from water objects

2020 ◽  
Keyword(s):  
Surface Layer ◽  
Energy Balance ◽  
Water Balance ◽  
Water Surface ◽  
Atmospheric Surface Layer ◽  
Water Bodies ◽  
Balance Model ◽  
Empirical Methods ◽  
Water Losses ◽  
Main Component

Formulation of the problem. When solving hydrological problems associated with the water balance of water bodies and the possibility of economic use of their water resources, an important problem is the accurate determination of evaporation from the water surface, which is the main component of water losses. Review of previous publications and studies.Currently, many indirect and empirical methods for calculating evaporation from the surface of soil, water and vegetation, developed by domestic and foreign scientists: M.I. Budyko, V.S. Mezentsev, A.R. Konstantinov, N.N. Ivanov, Penman-Monteith and others, are used. Most empirical methods do not have universal applicability, since, in most cases, they cannot take into account the features of various underlying surfaces and hydrometeorological conditions that affect evaporation processes. The only acceptable methods for estimating actual or potential evaporation can only be parametric models based on a numerical solution of the surface heat balance equation. One of such models is the atmospheric surface layer model – model SLEB, created at Odessa State Ecological Environmental University. Purpose. The purpose of this study is to obtain quantitative estimates of changes with evaporation of water surfaces with SLEB model and compare them with the measured and model data of analogous methods obtained by other authors (Ivanova, Penman), for example, a freshwater lake Yalpug. Methods. For research, a parametric energy balance model of the atmospheric surface layer SLEB, which is used standard meteorological information, was used. The main advantage of this model is the high accuracy of determining the heat expenditure for evaporation in the calculation of mass-heat transfer between the underlying surface and the atmosphere at the micro- and mesoscales. The SLEB model is applicable for all types of underlying surfaces characteristic of the territory of Ukraine. Results. The value of evaporation from unit area of the water surface of Lake Yalpug calculating by model SLEB was obtained for the first time taking into account the development of wave formation on the surface of the lake, which changes the hydrodynamic properties of the water surface and the aerodynamics of the air flow. Accounting for the effect of wind waves on the vast lake surface allowed us to obtain results almost equal to the measured evaporation from the pool surface. The results showed that the calculated values of evaporation from the water surface by the methods of Penman and Ivanov overestimate the amount of evaporated moisture compared with the values measured and calculated by the SLEB model. Conclusions. Application of the SLEB model allows to increase the quantitative estimation accuracy of the water balance main component – water losses due to evaporation from the water bodies water surface, which, in turn, can increase the water resources management efficiency of natural water bodies for purpose of their rational use for drinking water supply and land irrigation.

scholarly journals Evaluation of a Hybrid Reflectance-Based Crop Coefficient and Energy Balance Evapotranspiration Model for Irrigation Management

2018 ◽  
Vol 61 (2) ◽  
pp. 533-548 ◽  
Author(s):  
J. Burdette Barker ◽  
Christopher M. U. Neale ◽  
Derek M. Heeren ◽  
Andrew E. Suyker
Keyword(s):  
Remote Sensing ◽  
Energy Balance ◽  
Water Balance ◽  
Real Time ◽  
Eddy Covariance ◽  
Irrigation Management ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
Balance Model ◽  
Crop Coefficients

Abstract. Accurate generation of spatial soil water maps is useful for many types of irrigation management. A hybrid remote sensing evapotranspiration (ET) model combining reflectance-based basal crop coefficients (Kcbrf) and a two-source energy balance (TSEB) model was modified and validated for use in real-time irrigation management. We modeled spatial ET for maize and soybean fields in eastern Nebraska for the 2011-2013 growing seasons. We used Landsat 5, 7, and 8 imagery as remote sensing inputs. In the TSEB, we used the Priestly-Taylor (PT) approximation for canopy latent heat flux, as in the original model formulations. We also used the Penman-Monteith (PM) approximation for comparison. We compared energy balance fluxes and computed ET with measurements from three eddy covariance systems within the study area. Net radiation was underestimated by the model when data from a local weather station were used as input, with mean bias error (MBE) of -33.8 to -40.9 W m-2. The measured incident solar radiation appeared to be biased low. The net radiation model performed more satisfactorily when data from the eddy covariance flux towers were input into the model, with MBE of 5.3 to 11.2 W m-2. We removed bias in the daily energy balance ET using a dimensionless multiplier that ranged from 0.89 to 0.99. The bias-corrected TSEB ET, using weather data from a local weather station and with local ground data in thermal infrared imagery corrections, had MBE = 0.09 mm d-1 (RMSE = 1.49 mm d-1) for PM and MBE = 0.04 mm d-1 (RMSE = 1.18 mm d-1) for PT. The hybrid model used statistical interpolation to combine the two ET estimates. We computed weighting factors for statistical interpolation to be 0.37 to 0.50 for the PM method and 0.56 to 0.64 for the PT method. Provisions were added to the model, including a real-time crop coefficient methodology, which allowed seasonal crop coefficients to be computed with relatively few remote sensing images. This methodology performed well when compared to basal crop coefficients computed using a full season of input imagery. Water balance ET compared favorably with the eddy covariance data after incorporating the TSEB ET. For a validation dataset, the magnitude of MBE decreased from -0.86 mm d-1 (RMSE = 1.37 mm d-1) for the Kcbrf alone to -0.45 mm d-1 (RMSE = 0.98 mm d-1) and -0.39 mm d-1 (RMSE = 0.95 mm d-1) with incorporation of the TSEB ET using the PM and PT methods, respectively. However, the magnitudes of MBE and RMSE were increased for a running average of daily computations in the full May-October periods. The hybrid model did not necessarily result in improved model performance. However, the water balance model is adaptable for real-time irrigation scheduling and may be combined with forecasted reference ET, although the low temporal frequency of satellite imagery is expected to be a challenge in real-time irrigation management. Keywords: Center-pivot irrigation, ET estimation methods, Evapotranspiration, Irrigation scheduling, Irrigation water balance, Model validation, Variable-rate irrigation.

Monitoring evapotranspiration and water stress of Mediterranean oak savannas using optical and thermal remote sensing-based approaches

2020 ◽  
Author(s):  
Elisabet Carpintero ◽  
Ana Andreu ◽  
Pedro J. Gómez-Giráldez ◽  
María P. González-Dugo
Keyword(s):  
Remote Sensing ◽  
Water Stress ◽  
Energy Balance ◽  
Water Balance ◽  
Soil Water ◽  
Continuous Monitoring ◽  
Spectral Response ◽  
Balance Model ◽  
Landsat 8 ◽  
Management Actions

<p>In water-controlled systems, the evapotranspiration (ET) is a key indicator of the ecosystem health and the water status of the vegetation. Continuous monitoring of this variable over Mediterranean savannas (landscape consisting of widely-spaced oak trees combined with pasture, crops and shrubs) provides the baseline required to evaluate actual threats (e.g. vulnerable areas, land-use changes, invasive species, over-grazing, bush encroachment, etc.) and design management actions leading to reduce the economic and environmental vulnerability. However, the patched nature of these agropastoral ecosystems, with different uses (agricultural, farming, hunting), and their complex canopy structure, with various layers of vegetation and bare soil, pose additional difficulties. The combination of satellite mission with high/medium spatial/temporal resolutions provides appropriate information to characterize the variability of the Mediterranean savanna, assessing resource availability at local scales.</p><p>The aim of this work is to quantify ET and water stress at field-scale over a dehesa ecosystem located in Southern Spain, coupling remote sensing-based water and energy balance models. A soil water balance has been applied for five consecutive hydrological years (between 2012 and 2017) using the vegetation index (VI) based approach (VI-ETo model), on a daily scale and 30 m of spatial resolution. It combines FAO56 guidelines with the spectral response in the visible and near-infrared regions to compute more accurately the canopy transpiration. Landsat-8 and Sentinel-2 images, meteorological, and soil data have been used. This approach has been adapted to dehesa ecosystem, taking into account the double strata of annual grasses and tree canopies. However, the lack of available information about the spatial distribution of soil properties and the presence of multiple vegetation layers with very different root depths increase the uncertainty of water balance calculations. The combination with energy balance-based models may overcome these issues. In this case, the two-source energy balance model (TSEB) has been applied to explore the possibilities of integrating both approaches.  ET was estimated using TSEB in the days with available thermal data, more accurately assessing the reduction on ET due to soil water deficit, and allowing the adjustment of water stress coefficient in the VI-ETo model.</p><p>The modeled ET results have been validated with field observations (Santa Clotilde; 38º12’N, 4º17’ W; 736 m a.s.l.), measuring the energy balance components with an eddy covariance system and complementary instruments. The VI-ETo model has proven to be robust to monitor the vegetation water use of this complex ecosystem. However, the integration of the energy balance modelling has improved the estimations during the dry periods, with highly stressed vegetation, enabling a continuous monitoring of ET and water stress over this landscape.</p>

scholarly journals Estimation of actual evapotranspiration of Mediterranean perennial crops by means of remote-sensing based surface energy balance models

2009 ◽  
Vol 13 (7) ◽  
pp. 1061-1074 ◽  
Author(s):  
M. Minacapilli ◽  
C. Agnese ◽  
F. Blanda ◽  
C. Cammalleri ◽  
G. Ciraolo ◽  
...  
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Water Balance ◽  
Soil Water ◽  
Surface Energy Balance ◽  
Soil Water Balance ◽  
Actual Evapotranspiration ◽  
Balance Model ◽  
Spatially Distributed ◽  
Energy Balance Models

Abstract. Actual evapotranspiration from typical Mediterranean crops has been assessed in a Sicilian study area by using surface energy balance (SEB) and soil-water balance models. Both modelling approaches use remotely sensed data to estimate evapotranspiration fluxes in a spatially distributed way. The first approach exploits visible (VIS), near-infrared (NIR) and thermal (TIR) observations to solve the surface energy balance equation whereas the soil-water balance model uses only VIS-NIR data to detect the spatial variability of crop parameters. Considering that the study area is characterized by typical spatially sparse Mediterranean vegetation, i.e. olive, citrus and vineyards, alternating bare soil and canopy, we focused the attention on the main conceptual differences between one-source and two-sources energy balance models. Two different models have been tested: the widely used one-source SEBAL model, where soil and vegetation are considered as the sole source (mostly appropriate in the case of uniform vegetation coverage) and the two-sources TSEB model, where soil and vegetation components of the surface energy balance are treated separately. Actual evapotranspiration estimates by means of the two surface energy balance models have been compared vs. the outputs of the agro-hydrological SWAP model, which was applied in a spatially distributed way to simulate one-dimensional water flow in the soil-plant-atmosphere continuum. Remote sensing data in the VIS and NIR spectral ranges have been used to infer spatially distributed vegetation parameters needed to set up the upper boundary condition of SWAP. Actual evapotranspiration values obtained from the application of the soil water balance model SWAP have been considered as the reference to be used for energy balance models accuracy assessment. Airborne hyperspectral data acquired during a NERC (Natural Environment Research Council, UK) campaign in 2005 have been used. The results of this investigation seem to prove a slightly better agreement between SWAP and TSEB for some fields of the study area. Further investigations are programmed in order to confirm these indications.

Scale analysis of evapotranspiration estimates from an energy-water balance model and remotely sensed LST

2021 ◽  
Author(s):  
Nicola Paciolla ◽  
Chiara Corbari ◽  
Giuseppe Ciraolo ◽  
Antonino Maltese ◽  
Marco Mancini
Keyword(s):  
Energy Balance ◽  
High Resolution ◽  
Water Balance ◽  
Surface Temperature ◽  
Remotely Sensed ◽  
Water Balance Model ◽  
Balance Model ◽  
Source Surface ◽  
Scale Analysis ◽  
Energy Fluxes

<p>Remote Sensing (RS) information has progressively found, in recent years, more and more applications in hydrological modelling as a valuable tool for easy and frequent collection of geophysical data. However, this kind of data should be handled carefully, minding its characteristics, spatial resolution and the heterogeneity of the target area.</p><p>In this work, a scale analysis on evapotranspiration estimates over heterogeneous crops is performed combining a distributed energy-water balance model (FEST-EWB) and high-resolution remotely-sensed Land Surface Temperature (LST) and vegetation data.</p><p>The FEST-EWB model is calibrated on measured LST, based on a procedure where every single pixel is modified independently one from the other; hence in each pixel of the analysed domain the minimum of the pixel difference between modelled RET and satellite observed LST is searched over the period of calibration.</p><p>The case study is a Sicilian vineyard, with test dates in the summer of 2008. Meteorological and energy fluxes data are available from an eddy-covariance station, while LST and vegetation data are obtained from low-altitude flights at the high resolution of 1.7 metres.</p><p>After a preliminary calibration on LST data and validation on energy fluxes, the scale analysis is performed in two ways: model input aggregation and model output aggregation. Four coarser scales are selected in reference to some common satellite products resolution: 10.2 m (in reference to Sentinel’s 10 m), 30.6 m (Landsat, 30 m), 244.8 m (MODIS visible, 250 m) and 734.4 m (MODIS, 1000 m). First, modelled surface temperature and evapotranspiration are aggregated to each scale by progressive averaging. Then, model inputs are upscaled to the same spatial resolutions and the model is calibrated anew, obtaining independent results directly at the target scale.</p><p>The results of the two procedures are found to be quite similar, testifying to the capacity of the model to provide accurate products for a heterogeneous area even at low resolutions. The robustness of the analysis is strengthened by a further comparison with two well-established energy-balance algorithms: the one source Surface Energy Balance Algorithm for Land (SEBAL) and the Two-Source Energy Balance (TSEB) model.</p>

scholarly journals Aeration Tank Microbial Aerosols as a Factor of Water Bodies’ Pollution

2017 ◽  
Author(s):  
Keyword(s):  
Wind Velocity ◽  
Biological Treatment ◽  
Water Surface ◽  
Waste Water Treatment ◽  
Water Bodies ◽  
Aeration Tank ◽  
Waste Waters ◽  
Domestic Waste ◽  
Water Losses ◽  
Microbial Pollution

Aeration impact on aerosols discharge from aeration tanks in the process of domestic waste water treatment has been considered. Waste waters and their aerosols microbial pollution has been shown. New regularities of the temperature, time, and wind velocity on moisture discharge and microbial pollution in the form of aerosols from water surface of the biological treatment aerated facilities have been obtained. The equations that enable to calculate moisture emission from water surface in the process of aeration are presented. Water losses in the form of aerosols in the process of aeration depending on the outside air temperature and wind velocity were determined theoretically and experimentally. The microorganisms specific discharge from an aeration tank equal to 2.144 г/(m2∙s) in terms of coliform species was calculated. The microbial pollution maximal concentration values for various meteorological conditions were determined for performance of standard calculations of microbial discharges with aerosols from aeration tanks. The obtained equations can be used in designing of engineering measures aimed at reduction of the discharged aerosols negative microbial impact on water bodies adjacent to the territories of domestic waste waters biological treatment facilities.

scholarly journals STUDY OF QUANTITATIVE INDICATORS OF EVAPORATION FROM THE SURFACE OF WATER BODIES IN THE KUNDRYUCH’YA RIVER BASIN

2020 ◽  
Author(s):  
T. S. Ponomarenko ◽  
◽  
A. V. Breyeva ◽  
Keyword(s):  
Water Surface ◽  
Water Bodies ◽  
Water Losses ◽  
Long Term Conditions ◽  
Contour Map ◽  
Annual Distribution ◽  
Quantitative Indicators ◽  
Annual Amount ◽  
Made In

Purpose: analysis of predicted water losses for evaporation from the water surface of the Sokolovskiy reservoir and ponds located on the river Kundryuch’ya, within the boundaries of the investigated site on the territory of the Russian Federation from Rebrikovka to the Sokolovskiy reservoir site and the annual distribution of evaporation depending on the percentage availability. An assessment of the possible impact of quantitative indicators of evaporation on the water supply of the river Kundryuch’ya and Sokolovskiy reservoir was made. Materials and methods: for calculating the amount of precipitation, evaporation and irretrievable losses from the water surface of reservoirs located in the basin of the river Kundryuch’ya upstream the Sokolovskiy reservoir section, the formulas for average long-term conditions, formulas for calculating the volumes of evaporation and nonrecoverable losses at P = 10, 25, 50 and 75 % of supply, as well as a contour map were used. The formulas used and the contour map were taken from the textbook by G. V. Zheleznyakov “Hydrology, Hydrometry and Flow Regulation”. Results: the values of monthly evaporation as a percentage of the annual amount, as well as layers and volumes of evaporation for the Sokolovskiy reservoir are given. It has been determined that the share of nonrecoverable losses from the Sokolovskiy reservoir is 0.87, from the rest of the water bodies is 0.13. The amount of nonrecoverable losses at different levels of availability range from 2.64 million m³ (10 %) to 1.85 million m³ (75 %). Conclusions. The research results served as a basis for making a decision on the liquidation or further operation of the existing water retaining structures. In view of the low values of nonrecoverable losses from water bodies, which have an insignificant effect on the quantitative indicators of runoff, the decision was made in favor of further operation.

Mathematical modelling of the formation and evolution of surface ice

2020 ◽  
Author(s):  
Fisaha Unduche ◽  
John Doering
Keyword(s):  
Mathematical Model ◽  
Surface Layer ◽  
Turbulent Flows ◽  
Water Surface ◽  
Balance Model ◽  
Mixing Rate ◽  
Ice Conditions ◽  
Formation And Evolution ◽  
Surface Ice ◽  
The University

During the fall season in cold regions when the air temperature drops below freezing levels, it removes heat from the water surface and creates a supercooled surface layer. In weak turbulent flows, the supercooled surface layer initiates the formation of ice particles on the water surface, which could evolve into various types of surface ice runs. In this paper a mathematical model of the formation and evolution of surface ice is presented. A heat balance model at the water surface is applied to calculate the heat loss from the water. The turbulent kinetic energy and the energy dissipation rates are modelled to find the eddy viscosity that affects the mixing rate. The mathematical model is then calibrated and verified using experimental data collected at the Hydraulics Research and Testing Laboratory at the University of Manitoba. The model simulates the supercooling process reasonably well for all surface ice conditions.

scholarly journals Turbulent kinetic energy balance in the atmospheric surface layer over a tropical region

MAUSAM ◽  
2021 ◽  
Vol 48 (1) ◽  
pp. 15-22
Author(s):  
B. PADMANABHAMURTY ◽  
PIALI CHAKRABORTY
Keyword(s):  
Surface Layer ◽  
Energy Balance ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Energy Budget ◽  
Atmospheric Surface Layer ◽  
Tropical Region ◽  
Turbulent Kinetic Energy Budget ◽  
Similarity Relations ◽  
Kinetic Energy Budget

    ABSTRACT. The various tenns of the turbulent kinetic energy budget in the surface layer over Jodhpur, India have been worked out and compared with established similarity relations. The turbulent production and dissipation tend to balance under moderately unstable conditions for most of the runs considered for investigation.    

Daily cycle of the surface layer and energy balance on the high Antarctic Plateau

2005 ◽  
Vol 17 (1) ◽  
pp. 121-133 ◽  
Author(s):  
DIRK VAN AS ◽  
MICHIEL VAN DEN BROEKE ◽  
RODERIK VAN DE WAL
Keyword(s):  
Heat Flux ◽  
Surface Layer ◽  
Energy Balance ◽  
Wind Speed ◽  
Atmospheric Surface Layer ◽  
Specific Humidity ◽  
Inertial Oscillation ◽  
Sensible Heat ◽  
Daily Cycle ◽  
Near Surface

This paper focuses on the daily cycle of the surface energy balance and the atmospheric surface layer during a detailed meteorological experiment performed near Kohnen base in Dronning Maud Land, East Antarctica, in January and February 2002. Temperature, specific humidity, wind speed and the turbulent scales of these quantities, exhibit a strong daily cycle. The sensible heat flux cycle has a mean amplitude of ∼8 W m−2, while the latent heat flux has an amplitude of less than 2 W m−2, which is small compared to the amplitude of net radiation (∼ 35 W m−2) and sub-surface heat (∼ 25 W m−2). Between ∼ 9 and 16 h GMT convection occurs due to a slightly unstable atmospheric surface layer. At the end of the afternoon, the wind speed decreases abruptly and the mixed layer is no longer supported by the sensible heat input; the stratification becomes stable. At night a large near-surface wind shear is measured due to the presence of a nocturnal jet, which is likely to be katabatically driven, but can also be the result of an inertial oscillation. No strong daily cycle in wind direction is recorded, since both the katabatic forcing at night and the daytime forcing by the large-scale pressure gradient were directed approximately downslope during the period of measurement.

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