scholarly journals ESTIMATIVA DE EVAPOTRANSPIRAÇÃO E COEFICIENTE DE CULTURA DO TOMATEIRO INDUSTRIAL UTILIZANDO O ALGORITMO SAFER

Irriga ◽  
2018 ◽  
Vol 22 (3) ◽  
pp. 629-640 ◽  
Author(s):  
Déborah Lidya Sales ◽  
José Alves Júnior ◽  
Derblai Casaroli ◽  
Adão Wagner Pego Evangelista ◽  
João Mauricio Fernandes Souza
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Water Content ◽  
Soil Water Content ◽  
Satellite Images ◽  
Reference Evapotranspiration ◽  
Crop Coefficient ◽  
Balance Model ◽  
Local Dynamic ◽  
Water Requirements

ESTIMATIVA DE EVAPOTRANSPIRAÇÃO E COEFICIENTE DE CULTURA DO TOMATEIRO INDUSTRIAL UTILIZANDO O ALGORITMO SAFER  DEBORAH LIDYA ALVES SALES¹; JOSÉ ALVES JÚNIOR²; DERBLAI CASAROLI²; ADÃO WAGNER PEGO EVANGELISTA² E JOÃO MAURICIO FERNANDES SOUZA3 ¹Profª. Mestre da Faculdade Metropolitana de Anápolis FAMA/Av. Fernando Costa, 49 - Vila Jaiara St. Norte, Anápolis - GO, 75064-780, Brasil, email: [email protected]²,Prof. Doutor do Núcleo de Pesquisas em Clima e Recursos Hídricos do Cerrado – Escola de Agronomia - Universidade Federal de Goiás, Rodovia Goiânia / Nova Veneza, Km 0, Goiânia, Goiás, CEP: 74690-900, Brasil,  email: [email protected], [email protected], [email protected]. Doutor do Centro Universitário de Anápolis – UniEVANGÉLICA/Av. Universitária Km. 3, 5 - Cidade Universitária, Anápolis - GO, 75083-515, Brasil,  email:[email protected]  1 RESUMO Objetivo do estudo foi estimar a evapotranspiração atual (ETa), e os respectivos coeficientes de cultura de dois híbridos de tomateiro industrial pelo modelo de balanço de energia utilizando o algoritmo SAFER, com comparação com tradicional método micrometeorológico utilizando evapotranspiração de referência (ETo), com os Kcs recomendados pela FAO 56 e EMBRAPA. O estudo foi realizado na Fazenda cabeceira do Piracanjuba, no município de Silvânia-GO, no período de maio a agosto de 2015. Além disso, foi monitorado o potencial de água na folha e o conteúdo de água no solo pelo balanço hídrico dinâmico local. Os valores de Kcs estimados pelo método do SAFER apresentou significante correlação com os métodos FAO 56 e Embrapa (FAO 56, R² = 0,98; Embrapa, R² = 0,95). A ETc estimada pelo método do SAFER apresentou significante correlação com os métodos micrometeorológicos (FAO 56, R2 = 0,97; Embrapa, R2 = 0,97), podendo este ser utilizado para estimativa da ETa na região. Palavra-chaves: necessidade hídrica, imagens de satélite, balanço de energia, irrigação  SALES, D. L. A.; ALVES JÚNIOR, J.; DERBLAI, C.; SOUZA, J. M. F. EVAPOTRANSPIRATION ESTIMATE AND CROP COEFFICIENT OF INDUSTRIAL TOMATOES USING THE SAFER ALGORITHM  2 ABSTRACT The objective of this study was to estimate the current evapotranspiration and the respective cultivation coefficients of two industrial tomato hybrids by the energy balance model using the SAFER algorithm, using a traditional micrometeorological method using ETo (Penman-Monteith) reference evapotranspiration with the Kcs recommended by FAO 56 and EMBRAPA. The study was carried out at the Piracanjuba head farm, in the municipality of Silvânia, GO, from May to August 2015. In addition, the potential of leaf water and soil water content was monitored by the local dynamic water balance. The Kcs estimated by the SAFER method presented a significant correlation with the FAO 56 and Embrapa methods (FAO 56, R² = 0.98, Embrapa, R² = 0.95). The ETc estimated by the SAFER method showed a significant correlation with the micrometeorological methods (FAO 56, R2 = 0.97, Embrapa, R2 = 0.97), which could be used to estimate ETa in the region. Keywords: water requirements; satellite images; energy balance and 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.

scholarly journals Penerapan Zero Runoff System (ZROS) dan Efektivitas Penurunan Limpasan Permukaan Pada Lahan Miring di DAS Cidanau, Banten

2017 ◽  
Vol 23 (2) ◽  
pp. 102 ◽  
Author(s):  
Yanuar Chandra Wirasembada ◽  
Budi Indra Setiawan ◽  
Satyanto Krido Saptomo
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Conservation ◽  
Water Balance Model ◽  
Balance Model ◽  
Coefficient Of Determination ◽  
Before And After ◽  
Zero Runoff

Runoff is one of flood and erosion causal factor in Indonesia. Runoff occurred when rainfall cannot be infiltrated and flowed on the ground surface. Cidanau watershed has quite high rainfall average (2573 mm/year) so it has high runoff potential. Zero Runoff System (ZROS) is one of water conservation way which can infiltrate runoff to the ground using permeation structures. ZROS’s successful parameter in order to decreasing runoff rate can be observed by the soil water content differences before and after ZROS application. Soil water content estimation was conducted by water balance model with and without runoff and then it is compared with soil water content from measuring. The simulation results indicated that soil water content in the research field before and after ZROS application is 0.476 and 0.569 m3/m3 respectively. The simulation is also conducted for past 10 years (2004-2013) and resulted higher soil water content if ZROS were applied. This results indicates that ZROS capable to decrease and permeate runoff to the ground and then increase soil water content level. Water balance model with and without runoff has coefficient of determination (R2) 0.606. It means that this model could simulate the soil water content differences before and after ZROS application valid relatively.

Forecasting wheat yields using a water budgeting model

1989 ◽  
Vol 40 (4) ◽  
pp. 715 ◽  
Author(s):  
I Cordery ◽  
AG Graham
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
Meteorological Data ◽  
New South Wales ◽  
Balance Model ◽  
Soil Layers ◽  
South Wales

A model has been developed to forecast soil water variations and wheat crop growth in dry land situations. The forecast of the yield to be expected if sowing occurred today is obtained by running the calibrated model for all years for which meteorological data are available. The soil water content on today's date in each year is fixed at today's observed soil water value. From each year of observed meteorological data, an estimate is made of the yield. These yield data allow construction of a frequency distribution of yield which can be used to make a probabilistic forecast. The model involves two sub-models, a water balance model and acrop development model. The two sub-models interact to provide 5-day estimates of soil water content, actual evaporation and transpiration, runoff and increments to biomass and grain yield. The water balance model takes inputs of daily rainfall and estimated potential evapotranspiration. Available energy is partitioned between evaporation and transpiration depending on leaf area index. There are two soil layers plus a surface interception and depression store. Water removal from the soil layers is dependent on root development and the location of available water. Biomass production is driven by actual transpiration and transpiration efficiency and so biomass and grain development are dependent on the timing and amount of water and energy utilization by the crop. The model was first calibrated in northern New South Wales with 13 years of research station data. With minor recalibration, it provided good estimates of observed district wheat harvests for a continuous period of 75 years. Further recalibration with 30 years of shire data from Queensland, 29 years of single farm data in southern New South Wales and with 31 years of county data from northwestern USA., indicated the model is able to accurately reproduce observed yields and has the potential to provide reliable forecasts of yield, in a range of different climates.

scholarly journals Energy balance closure on a winter wheat stand: comparing the eddy covariance technique with the soil water balance method

2015 ◽  
Vol 12 (9) ◽  
pp. 6783-6820 ◽  
Author(s):  
K. Imukova ◽  
J. Ingwersen ◽  
M. Hevart ◽  
T. Streck
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Winter Wheat ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Eddy Covariance ◽  
Soil Water Balance ◽  
Flux Data ◽  
Closure Method

Abstract. The energy balance of eddy covariance (EC) flux data is typically not closed. The nature of the gap is usually not known, which hampers using EC data to parameterize and test models. The present study elucidates the nature of the energy gap of EC flux data from winter wheat stands in southwest Germany. During the vegetation periods 2012 and 2013, we continuously measured, in a half-hourly resolution, latent (LE) and sensible (H) heat fluxes using the EC technique. Measured fluxes were adjusted with either the Bowen-ratio (BR), H or LE post-closure method. The adjusted LE fluxes were tested against evapotranspiration data (ETWB) calculated using the soil water balance (WB) method. At sixteen locations within the footprint of an EC station, the soil water storage term was determined by measuring the soil water content down to a soil depth of 1.5 m. In the second year, the volumetric soil water content was also continuously measured in 15 min resolution in 10 cm intervals down to 90 cm depth with sixteen capacitance soil moisture sensors. During the 2012 vegetation period, the H post-closed LE flux data (ETEC = 3.4 ± 0.6 mm day−1) corresponded closest with the result of the WB method (3.3 ± 0.3 mm day−1). ETEC adjusted by the BR (4.1 ± 0.6 mm day−1) or LE (4.9 ± 0.9 mm day−1) post-closure method were higher than the ETWB by 20 and 33%, respectively. In 2013, ETWB was in best agreement with ETEC adjusted with the H post-closure method during the periods with low amount of rain and seepage. During these periods the BR and LE post-closure methods overestimated ET by about 30 and 40%, respectively. During a period with high and frequent rainfalls, ETWB was in-between ETEC adjusted by H and BR post-closure methods. We conclude that, at most vegetation periods on our site, LE is not a~major component of the energy balance gap. Our results indicate that the energy balance gap other energy fluxes and unconsidered or biased energy storage terms.

The performance of Metop Advanced SCATterometer soil moisture data as a complementary source for the estimation of crop-soil water balance in Central Europe

2018 ◽  
Vol 156 (5) ◽  
pp. 577-598 ◽  
Author(s):  
S. Thaler ◽  
J. Eitzinger ◽  
M. Trnka ◽  
M. Možný ◽  
S. Hahn ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Status ◽  
Soil Water Balance ◽  
Balance Model ◽  
Spatial Average ◽  
Soil Wetness

AbstractSimulation of the water balance in cropping systems is an essential tool, not only to monitor water status and determine drought but also to find ways in which soil water and irrigation water can be used more efficiently. However, besides the requirement that models are physically correct, the spatial representativeness of input data and, in particular, accurate precipitation data remain a challenge. In recent years, satellite-based soil moisture products have become an important data source for soil wetness information at various spatial-temporal scales. Four different study areas in the Czech Republic and Austria were selected representing Central European soil and climatic conditions. The performance of soil water content outputs from two different crop-water balance models and the Metop Advanced SCATterometer (ASCAT) soil moisture product was tested with field measurements from 2007 to 2011. The model output for soil water content shows that the crop model Decision Support System for Agrotechnology Transfer performs well during dry periods (<30% plant available soil moisture (ASM), whereas the soil water-balance model SoilClim presents the best results in humid months (>60% ASM). Moreover, the model performance is best in the early growing season and decreases later in the season due to biases in simulated crop-related above-ground biomass compared with the relatively stable grass canopy of the measurement sites. The Metop ASCAT soil moisture product, which presents a spatial average of soil surface moisture, shows the best performance under medium soil wetness conditions (30–50% ASM), which is related to low variation in precipitation frequency and under conditions of low-surface biomass (early vegetation season).

scholarly journals Energy balance closure on a winter wheat stand: comparing the eddy covariance technique with the soil water balance method

2016 ◽  
Vol 13 (1) ◽  
pp. 63-75 ◽  
Author(s):  
K. Imukova ◽  
J. Ingwersen ◽  
M. Hevart ◽  
T. Streck
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Winter Wheat ◽  
Water Content ◽  
Soil Water ◽  
Water Storage ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Water Balance Method ◽  
Closure Method

Abstract. The energy balance of eddy covariance (EC) flux data is typically not closed. The nature of the gap is usually not known, which hampers using EC data to parameterize and test models. In the present study we cross-checked the evapotranspiration data obtained with the EC method (ETEC) against ET rates measured with the soil water balance method (ETWB) at winter wheat stands in southwest Germany. During the growing seasons 2012 and 2013, we continuously measured, in a half-hourly resolution, latent heat (LE) and sensible (H) heat fluxes using the EC technique. Measured fluxes were adjusted with either the Bowen-ratio (BR), H or LE post-closure method. ETWB was estimated based on rainfall, seepage and soil water storage measurements. The soil water storage term was determined at sixteen locations within the footprint of an EC station, by measuring the soil water content down to a soil depth of 1.5 m. In the second year, the volumetric soil water content was additionally continuously measured in 15 min resolution in 10 cm intervals down to 90 cm depth with sixteen capacitance soil moisture sensors. During the 2012 growing season, the H post-closed LE flux data (ETEC =  3.4 ± 0.6 mm day−1) corresponded closest with the result of the WB method (3.3 ± 0.3 mm day−1). ETEC adjusted by the BR (4.1 ± 0.6 mm day−1) or LE (4.9 ± 0.9 mm day−1) post-closure method were higher than the ETWB by 24 and 48 %, respectively. In 2013, ETWB was in best agreement with ETEC adjusted with the H post-closure method during the periods with low amount of rain and seepage. During these periods the BR and LE post-closure methods overestimated ET by about 46 and 70 %, respectively. During a period with high and frequent rainfalls, ETWB was in-between ETEC adjusted by H and BR post-closure methods. We conclude that, at most observation periods on our site, LE is not a major component of the energy balance gap. Our results indicate that the energy balance gap is made up by other energy fluxes and unconsidered or biased energy storage terms.

Soil water content and water balance in rainfed fields in Northeast Thailand

2009 ◽  
Vol 96 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Toshitsugu Moroizumi ◽  
Hiromasa Hamada ◽  
Somsak Sukchan ◽  
Masahiro Ikemoto
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Northeast Thailand

scholarly journals The impact of broadleaved woodland on water resources in lowland UK: I. Soil water changes below beech woodland and grass on chalk sites in Hampshire

2005 ◽  
Vol 9 (6) ◽  
pp. 596-606 ◽  
Author(s):  
J. Roberts ◽  
P. Rosier
Keyword(s):  
Energy Balance ◽  
Water Potential ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Water Potential ◽  
Eddy Correlation ◽  
Seasonal Differences ◽  
Water Potential Measurements ◽  
Shallow Soils

Abstract. The possible effects of broadleaved woodland on recharge to the UK Chalk aquifer have led to a study of evaporation and transpiration from beech woodland (Black Wood) and pasture (Bridgets Farm), growing in shallow soils above chalk in Hampshire. Eddy correlation measurements of energy balance components above both the forest and the grassland enabled calculation of latent heat flux (evaporation and transpiration) as a residual. Comparative measurements of soil water content and soil water potential in 9 m profiles under both forest and grassland found changes in soil water content down to 6 m at both sites; however, the soil water potential measurements showed upward movement of water only above a depth of about 2 m. Below this depth, water continued to drain and the soil water potential measurements showed downward movement of water at both sites, notwithstanding significant negative soil water potentials in the chalk and soil above. Seasonal differences occur in the soil water content profiles under broadleaved woodland and grass. Before the woodland foliage emerges, greater drying beneath the grassland is offset in late spring and early summer by increased drying under the forest. Yet, when the change in soil water profiles is at a maximum, in late summer, the profiles below woodland and grass are very similar. A comparison of soil water balances for Black Wood and Bridgets Farm using changes in soil water contents, local rainfall and evaporation measured by the energy balance approach allowed drainage to be calculated at each site. Although seasonal differences occurred, the difference in cumulative drainage below broadleaved woodland and grass was small.

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