scholarly journals Field Water Balance Closure with Actively Heated Fiber-Optics and Point-Based Soil Water Sensors

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 135 ◽  
Author(s):  
Duminda Vidana Gamage ◽  
Asim Biswas ◽  
Ian Strachan
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Fiber Optics ◽  
Soil Water Storage ◽  
Small Scale ◽  
Field Scale ◽  
Future Studies ◽  
Distributed Sensor ◽  
Time Periods ◽  
Field Water Balance

While traditional soil water sensors measure soil water content (SWC) at point scale, the actively heated fiber-optics (AHFO) sensor measures the SWC at field scale. This study compared the performance of a distributed (e.g., AHFO) and a point-based sensor on closing the field water balance and estimating the evapotranspiration (ET). Both sensors failed to close the water balance and produced larger errors in estimated ET (ETε), particularly for longer time periods with >60 mm change in soil water storage (ΔSWS), and this was attributed to a lack of SWC measurements from deeper layers (>0.24 m). Performance of the two sensors was different when only the periods of ˂60 mm ΔSWS were considered; significantly lower residual of the water balance (Re) and ETε of the distributed sensor showed that it could capture the small-scale spatial variability of SWC that the point-based sensor missed during wet (70–104 mm SWS) periods of ˂60 mm ΔSWS. Overall, this study showed the potential of the distributed sensor to provide a more accurate value of SWS at field scale and to reduce the errors in water balance for shorter wet periods. It is suggested to include SWC measurements from deeper layers to better evaluate the performance of the distributed sensor, especially for longer time periods of >60 mm ΔSWS, in future studies.

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.

scholarly journals A Daily Water Balance Model Based on the Distribution Function Unifying Probability Distributed Model and the SCS Curve Number Method

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 143
Author(s):  
Marwan Kheimi ◽  
Shokry M. Abdelaziz
Keyword(s):  
Distribution Function ◽  
Water Balance ◽  
Soil Water ◽  
Storage Tank ◽  
Water Storage ◽  
Curve Number ◽  
Water Balance Model ◽  
Balance Model ◽  
Soil Water Storage ◽  
Daily Water

A new daily water balance model is developed and tested in this paper. The new model has a similar model structure to the existing probability distributed rainfall runoff models (PDM), such as HyMOD. However, the model utilizes a new distribution function for soil water storage capacity, which leads to the SCS (Soil Conservation Service) curve number (CN) method when the initial soil water storage is set to zero. Therefore, the developed model is a unification of the PDM and CN methods and is called the PDM–CN model in this paper. Besides runoff modeling, the calculation of daily evaporation in the model is also dependent on the distribution function, since the spatial variability of soil water storage affects the catchment-scale evaporation. The generated runoff is partitioned into direct runoff and groundwater recharge, which are then routed through quick and slow storage tanks, respectively. Total discharge is the summation of quick flow from the quick storage tank and base flow from the slow storage tank. The new model with 5 parameters is applied to 92 catchments for simulating daily streamflow and evaporation and compared with AWMB, SACRAMENTO, and SIMHYD models. The performance of the model is slightly better than HyMOD but is not better compared with the 14-parameter model (SACRAMENTO) in the calibration, and does not perform as well in the validation period as the 7-parameter model (SIMHYD) in some areas, based on the NSE values. The linkage between the PDM–CN model and long-term water balance model is also presented, and a two-parameter mean annual water balance equation is derived from the proposed PDM–CN model.

Residue Management Impacts on Field-Scale Snow Distribution and Soil Water Storage

2011 ◽  
Vol 54 (5) ◽  
pp. 1639-1647 ◽  
Author(s):  
H. Qiu ◽  
D. R. Huggins ◽  
J. Q. Wu ◽  
M. E. Barber ◽  
D. K. McCool ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Storage ◽  
Residue Management ◽  
Soil Water Storage ◽  
Field Scale ◽  
Snow Distribution

scholarly journals Diagnosis toward predicting mean annual runoff in ungauged basins

2021 ◽  
Vol 25 (2) ◽  
pp. 945-956
Author(s):  
Yuan Gao ◽  
Lili Yao ◽  
Ni-Bin Chang ◽  
Dingbao Wang
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Storage Capacity ◽  
Water Storage ◽  
Annual Runoff ◽  
Balance Model ◽  
Soil Water Storage ◽  
Ungauged Basins ◽  
Water Storage Capacity ◽  
Soil Water Storage Capacity

Abstract. Prediction of mean annual runoff is of great interest but still poses a challenge in ungauged basins. The present work diagnoses the prediction in mean annual runoff affected by the uncertainty in estimated distribution of soil water storage capacity. Based on a distribution function, a water balance model for estimating mean annual runoff is developed, in which the effects of climate variability and the distribution of soil water storage capacity are explicitly represented. As such, the two parameters in the model have explicit physical meanings, and relationships between the parameters and controlling factors on mean annual runoff are established. The estimated parameters from the existing data of watershed characteristics are applied to 35 watersheds. The results showed that the model could capture 88.2 % of the actual mean annual runoff on average across the study watersheds, indicating that the proposed new water balance model is promising for estimating mean annual runoff in ungauged watersheds. The underestimation of mean annual runoff is mainly caused by the underestimation of the area percentage of low soil water storage capacity due to neglecting the effect of land surface and bedrock topography. Higher spatial variability of soil water storage capacity estimated through the height above the nearest drainage (HAND) and topographic wetness index (TWI) indicated that topography plays a crucial role in determining the actual soil water storage capacity. The performance of mean annual runoff prediction in ungauged basins can be improved by employing better estimation of soil water storage capacity including the effects of soil, topography, and bedrock. It leads to better diagnosis of the data requirement for predicting mean annual runoff in ungauged basins based on a newly developed process-based model finally.

scholarly journals DINÂMICA DA ÁGUA NOS RESÍDUOS CULTURAIS EM UM SISTEMA IRRIGADO

Irriga ◽  
2018 ◽  
Vol 23 (4) ◽  
pp. 622-636
Author(s):  
Marta Rodrigues da Rocha ◽  
Reimar Carlesso ◽  
Mirta Teresinha Petry ◽  
Laudenir Juciê Basso ◽  
Sônia Thais Menegaz
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Crop Residues ◽  
Irrigation Event ◽  
Water Dynamics ◽  
Soil Water Storage ◽  
Experimental Unit ◽  
Time Interval ◽  
Irrigation Depth ◽  
Santa Maria

DINÂMICA DA ÁGUA NOS RESÍDUOS CULTURAIS EM UM SISTEMA IRRIGADO     MARTA RODRIGUES DA ROCHA1; REIMAR CARLESSO2; MIRTA TERESINHA PETRY3; LAUDENIR JUCIÊ BASSO4 E SÔNIA THAIS MENEGAZ5   1Doutora em Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola (PPGEA), Universidade Federal de Santa Maria (UFSM), Av. Roraima, n°1000 – Camobi, Santa Maria/ RS/ Brasil, CEP: 97105-900, [email protected]; 2Universidade Federal de Santa Maria, Departamento de Engenharia Rural, Av. Roraima, n°1000 – Camobi, Santa Maria/ RS/ Brasil, CEP: 97105-900, Santa Maria, RS. [email protected]; 3 Universidade Federal de Santa Maria, Departamento de Engenharia Rural, Av. Roraima, n°1000 – Camobi, Santa Maria/ RS/ Brasil, CEP: 97105-900, Santa Maria, RS, UFSM, [email protected];  4Mestrando do PPGEA, Universidade Federal de Santa Maria (UFSM), Av. Roraima, n°1000 – Camobi, Santa Maria/ RS/ Brasil, CEP: 97105-900, [email protected];  5Mestranda em Ciência do Solo e Qualidade da Água, Universidade de Minnesota, Minneapolis, MN 55455, Saint Paul/ Minnesota/ EUA, [email protected].     1 RESUMO   A redução da evaporação e maior conservação de água no solo são apontados como as vantagens da manutenção dos resíduos na superfície do solo, no Sistema Plantio Direto. Quantificar com acurácia a água conservada no solo é necessário, uma vez que, os efeitos benéficos são controversos. Por outro lado, uma intensa camada de resíduos pode reter grande parte da água de irrigação ou da chuva quando as lâminas forem pequenas, além de dificultar as operações de semeadura. Assim, o objetivo desse trabalho foi quantificar a interceptação de água de irrigação pelos resíduos culturais e o seu efeito nos componentes do balanço hídrico do solo. Para tanto, foi conduzido um experimento na Universidade Federal de Santa Maria, durante 60 dias, nos anos de 2013 e 2014, sob uma cobertura móvel, em parcelas de 9 m2. Utilizou-se um delineamento bi-fatorial, com três repetições, onde o fator A foi constituído de três níveis de cobertura do solo: 0; 2 e 4 t ha-1 de resíduos de aveia preta. O fator B foi constituído de três lâminas de irrigação (menor, intermediária e maior). Após cada evento de irrigação, uma amostra de 0,09 m2 de resíduos vegetais era coletada e pesada, em intervalos de 0; 3; 6 e 24 horas após a irrigação, a fim de medir a água retida pelos resíduos. O conteúdo de água no solo foi monitorado em cada unidade experimental, até a profundidade de 85 cm, utilizando-se um conjunto de sensores FDR (Reflectometria de domínio de frequência). O balanço hídrico do solo foi determinado pela relação entre a lâmina aplicada, subtraída da lâmina infiltrada, a água retida pelo resíduo vegetal e da lâmina evaporada, após cada evento de irrigação. O uso de cobertura sobre o solo é uma maneira eficiente para reduzir a Es, entretanto a água interceptada pelos resíduos vegetais é evaporada, e esta perda deve ser considerada, especialmente quando se trata de pequenas e frequentes lâminas de irrigação por aspersão.   Palavras-chave: Balanço Hídrico do Solo, Evaporação, Interceptação.     ROCHA, M. R.; CARLESSO, R.; PETRY, M. T.; BASSO, L. J.; MENEGAZ, S. T. WATER DYNAMICS IN AN IRRIGATED SYSTEM’S CROP RESIDUES 2 ABSTRACT   Accurately quantifying soil water storage is necessary, since the beneficial effects of a thick mulch layer are controversial. Nevertheless, an intense layer of mulch can retain much of the small irrigation depths or precipitation, as well as hamper sowing operations. The intent of this paper is to quantify  water interception by crop residues and the effect in the water balance components in the soil. The experiment was conducted in the Federal University of Santa Maria, during 60 days, in 2013 and 2014, under rainout shelter, in 9 m2 plots. Bi- factorial delineation was used, with three repetitions, where factor A was constituted of three levels of soil mulching: 0; 2 and 4 t ha-1 of dry black oat residues. Factor B was constituted of three irrigation depths. After every irrigation event, a sample of 0.09 m² of crop residues was collected and weighted, in a time interval of 0; 3; 6 and 24 hours after irrigation, in order to measure the residues retained water. Soil water content was monitored in each experimental unit, to the depth of 85 cm, using a set of FDR sensors (Frequency domain reflectometers). The soil water balance was determined by the relation between irrigation depth applied, subtracted from the infiltrated irrigation depth, the water retained by the residues and the evaporated irrigation depth, after every irrigation event.   Keywords: Water balance, Evaporated, Interception.

scholarly journals Field monitoring and model predicted water balance of monolithic cover

2021 ◽  
Vol 337 ◽  
pp. 04009
Author(s):  
Md Jobair Bin Alam ◽  
Asif Ahmed ◽  
Md Aminul Islam ◽  
Naima Rahman ◽  
Md Sahadat Hossain
Keyword(s):  
Water Balance ◽  
Climatic Conditions ◽  
Soil Water Storage ◽  
Soil Parameters ◽  
Fine Grained ◽  
Future Performance ◽  
Fine Grained Soil ◽  
Actual Field ◽  
Field Water Balance

The use of the evapotranspiration cover for landfill is increasing because of its long-term enhanced performance. However, the performance of evapotranspiration cover primarily depends on the onsite geo-climatic conditions. Therefore, field verification of cover performance through constructed test plots is required before actual implementation. Additionally, numerical modeling and comparison with field results are necessary for future performance prediction. The objective of this study was to simulate the water balance hydrology of evapotranspiration cover using the code SEEP/W. Drainage lysimeter was constructed with fine-grained soil and native vegetation. Field water balance data from the lysimeter were obtained through instrumentation. Onsite climatological data, laboratory and field investigated soil parameters and actual field studied plant parameters were used as model input. Based on one year’s simulation, it was observed that the code nearly captured the seasonal variations in the water balance quantities measured in the field. Surface runoff was reasonably predicted in the model where precipitation intensity appeared to be responsible to some extent. Evapotranspiration was slightly overpredicted and the fluctuation in soil water storage was similar to the field results. The model predicted annual percolation was approximately 45 mm, which is under-predicted than the actual field measured annual percolation of 62 mm.

scholarly journals A stochastic approach for the description of the water balance dynamics in a river basin

2008 ◽  
Vol 12 (5) ◽  
pp. 1189-1200 ◽  
Author(s):  
S. Manfreda ◽  
M. Fiorentino
Keyword(s):  
Water Balance ◽  
Probability Density ◽  
Soil Water ◽  
Storage Capacity ◽  
Water Storage ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Water Storage Capacity ◽  
Soil Water Storage Capacity ◽  
Balance Dynamics

Abstract. The present paper introduces an analytical approach for the description of the soil water balance dynamics over a schematic river basin. The model is based on a stochastic differential equation where the rainfall forcing is interpreted as an additive noise in the soil water balance. This equation can be solved assuming known the spatial distribution of the soil moisture over the basin transforming the two-dimensional problem in space in a one dimensional one. This assumption is particularly true in the case of humid and semihumid environments, where spatial redistribution becomes dominant producing a well defined soil moisture pattern. The model allowed to derive the probability density function of the saturated portion of a basin and of its relative saturation. This theory is based on the assumption that the soil water storage capacity varies across the basin following a parabolic distribution and the basin has homogeneous soil texture and vegetation cover. The methodology outlined the role played by the soil water storage capacity distribution of the basin on soil water balance. In particular, the resulting probability density functions of the relative basin saturation were found to be strongly controlled by the maximum water storage capacity of the basin, while the probability density functions of the relative saturated portion of the basin are strongly influenced by the spatial heterogeneity of the soil water storage capacity. Moreover, the saturated areas reach their maximum variability when the mean rainfall rate is almost equal to the soil water loss coefficient given by the sum of the maximum rate of evapotranspiration and leakage loss in the soil water balance. The model was tested using the results of a continuous numerical simulation performed with a semi-distributed model in order to validate the proposed theoretical distributions.

scholarly journals Runoff generation dynamics within a humid river basin

2008 ◽  
Vol 8 (6) ◽  
pp. 1349-1357 ◽  
Author(s):  
S. Manfreda
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
River Basin ◽  
Parameters Estimation ◽  
Soil Water Balance ◽  
Soil Water Storage ◽  
Runoff Generation ◽  
Water Storage Capacity ◽  
Soil Water Storage Capacity ◽  
Runoff Production

Abstract. The present paper introduces an analytical approach for the description of the soil water balance and runoff production within a schematic river basin. The model is based on a stochastic differential equation where the rainfall is interpreted as an additive noise in the soil water balance and is assumed uniform over the basin, the basin heterogeneity is characterized by a parabolic distribution of the soil water storage capacity and the runoff production occurs for saturation excess. The model allowed to derive the probability density function of the produced surface runoff highlighting the role played by climate and physical characteristics of a basin on runoff dynamics. Finally, the model have been tested over a humid basin of Southern Italy proposing also a strategy for the parameters estimation.

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