Influence of calibration period length on predictions of evaporation 

2021 ◽  
Author(s):  
Chengcheng Gong ◽  
Wenke Wang ◽  
Zaiyong Zhang ◽  
Harrie-Jan Hendricks Franssen ◽  
Fabien Cochand ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Perfect Match ◽  
Bare Soil ◽  
Soil Evaporation ◽  
Period Length ◽  
Accurate Estimation ◽  
Calibration Period ◽  
Bare Soil Evaporation

<p>Bare soil evaporation is a key component of the soil water balance. Accurate estimation of evaporation is thus critical for sustainable water resources management, especially in arid and semi-arid regions. Numerical models are widely used for estimating bare soil evaporation. Although models allow exploring evaporation dynamics under different hydrological and climatic conditions, their robustness is linked to the reliability of the imposed parameters. These parameters are typically obtained through model calibration. Even if a perfect match between observed and simulated variables is obtained, the predictions are not necessarily reliable. This can be related to model structural errors, or because the inverse problem is ill-posed. While this is conceptually very well known, it remains unclear how the temporal resolution and length of the employed observations for the calibration influence the reliability of the parameters and the predictions.</p><p>We used data from a lysimeter experiment in the Guanzhong Basin, China to systematically explore the influence of the calibration period length on the calibrated parameters and uncertainty of evaporation predictions. Soil water content dynamics and water level were monitored every 5 minutes. We set up twelve models using the fully coupled, physically-based HydroGeoSphere model with different calibration period lengths (one month, three months, six months, fourteen months). The estimated evaporation rates by the models for the calibration period and validation period were compared with the measured evaporation rates. Also, we predict cumulative, one-year evaporation rates. The uncertainty of the predictive evaporation by these models from different calibration lengths is quantified. Several key conclusions can be drawn as follows: (1) The extinction depth is a very important parameter for the soil water content dynamics in the vadose zone but is poorly informed unless the calibration includes significantly different depths to groundwater. (2) Using the longer calibration period length (six months or fourteen months) did not necessarily result in more reliable predictions of evaporation rates. (3) Preliminary results indicate that the uncertainty can be reduced if the calibration period includes both climatic forcing similar to the prediction, but additionally also feature similar water table conditions during calibration and prediction. Our results have implications for reducing uncertainty using unsaturated-saturated models to predict evaporation.</p>

scholarly journals A bench-scale assessment of the effect of soil temperature on bare soil evaporation in winter

2020 ◽  
Vol 51 (6) ◽  
pp. 1349-1357
Author(s):  
Peigui Liu ◽  
Yan Xia ◽  
Manting Shang
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Movement ◽  
Bare Soil ◽  
Soil Evaporation ◽  
Factors Affecting ◽  
Bare Soil Evaporation ◽  
Soil Water Movement

Abstract To quantitatively evaluate in the laboratory the effect of soil temperature on bare soil evaporation, this study uses two indoor soil columns and homogenized sand as an example to carry out the experimental study of soil temperature on bare soil evaporation in winter. The results show that the soil temperature directly affects the change in bare soil evaporation and that the effect decreases as the soil temperature decreases. Because of the influence of soil temperature, the soil water movement accelerates, and the soil water content increases. At a depth of 50 cm, the average difference in soil water content between groups A and B was 7.61%. The soil evaporation when considering the soil temperature was obviously greater than that without considering the soil temperature. This shows that in a laboratory environment where the soil temperature is higher than the room temperature in winter, the effect of the soil temperature on bare soil evaporation is significant. Soil temperature directly affects soil water movement and distribution, which is one of the important influencing factors affecting bare soil evaporation.

scholarly journals Heat Balance and Soil Water Content for Bare Soil Surfaces in the Loess Plateau, China

2005 ◽  
Vol 60 (5) ◽  
pp. 1013-1016
Author(s):  
Reiji KIMURA ◽  
Yuanbo LIU ◽  
Naru TAKAYAMA ◽  
Makio KAMICHIKA ◽  
Nobuhiro MATSUOKA ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Loess Plateau ◽  
Heat Balance ◽  
Bare Soil ◽  
The Loess Plateau

Simulation of the transient soil water content profile for a homogeneous bare soil

1991 ◽  
Vol 27 (6) ◽  
pp. 1271-1279 ◽  
Author(s):  
Randall J. Charbeneau ◽  
Robert G. Asgian
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Bare Soil

scholarly journals Estimate Cotton Water Consumption from Shallow Groundwater under Different Irrigation Schedules

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 213
Author(s):  
Guohua Zhang ◽  
Xinhu Li
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Consumption ◽  
Meteorological Factors ◽  
Shallow Groundwater ◽  
Soil Evaporation ◽  
Groundwater Depth ◽  
Crop Water ◽  
Crop Water Consumption

Shallow groundwater is considered an important water resource to meet crop irrigation demands. However, limited information is available on the application of models to investigate the impact of irrigation schedules on shallow groundwater depth and estimate evaporation while considering the interaction between meteorological factors and the surface soil water content (SWC). Based on the Richards equation, we develop a model to simultaneously estimate crop water consumption of shallow groundwater and determine the optimal irrigation schedule in association with a shallow groundwater depth. A new soil evaporation function was established, and the control factors were calculated by using only the days after sowing. In this study, two irrigation scheduling methods were considered. In Method A, irrigation was managed based on the soil water content; in Method B, irrigation was based on the crop water demand. In comparison with Method B, Method A was more rational because it could use more groundwater, and the ratio of soil evaporation to total evapotranspiration was low. In this model, the interaction between meteorological factors and the SWC was considered to better reflect the real condition; therefore, the model provided a better way to estimate the crop water consumption.

Evaluation of radiant canopy temperature and soil water measurement for quantifying the contribution of shallow watertables to crop evaporation.

Soil Research ◽  
1990 ◽  
Vol 28 (6) ◽  
pp. 1013 ◽  
Author(s):  
L Mateos ◽  
WS Meyer ◽  
RCG Smith ◽  
R Sides
Keyword(s):  
Heat Flux ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Aerodynamic Resistance ◽  
Sensible Heat Flux ◽  
Canopy Temperature ◽  
Balance Model ◽  
Accurate Estimation ◽  
Clay Loam

Accurate estimation of the contribution of shallow watertables to crop water consumption is of major importance for improved irrigation practice and watertable management. A water balance model based on radiant canopy temperature estimations of crop evaporation and measurements of the change in the soil water content with a neutron probe was used to estimate the net upward flux from the watertable. The model was tested against measurements made by using two weighing lysimeters containing loam and clay loam soils, and the estimation of errors involved was analysed. The watertable in the lysimeters was maintained 1 m below the ground surface. Evaporation from a soybean crop was estimated by using an energy balance model with measured values of net radiant energy and soil heat flux. Sensible heat flux was calculated from the difference between the radiant canopy temperature and air temperature, together with an estimated aerodynamic resistance of the crop. Two sources of error were associated with the model, one due to the estimation of crop evaporation and the other due to the measurement of the change in soil water content. Errors of 0.7 and 5.1 mm per day were estimated for the first and second sources respectively. The accuracy of the method was determined by the length of the period considered and by the contribution of the watertable itself. An error of 20% was estimated when periods of 20 and 80 days were considered in the loam and clay loam soils respectively. Shorter time periods will result in larger uncertainty. The implications of the these results for watertable management are discussed.

scholarly journals State-space approach for the analysis of soil water content and temperature in a sugarcane crop

1999 ◽  
Vol 56 (4 suppl) ◽  
pp. 1215-1221 ◽  
Author(s):  
Durval Dourado-Neto ◽  
Luís Carlos Timm ◽  
Julio Cesar Martins de Oliveira ◽  
Klaus Reichardt ◽  
Osny Oliveira Santos Bacchi ◽  
...  
Keyword(s):  
State Space ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Management Practices ◽  
Bare Soil ◽  
The State ◽  
Ratoon Crop ◽  
State Space Approach ◽  
Space Approach

The state-space approach is used to describe surface soil water content and temperature behaviour, in a field experiment in which sugarcane is submitted to different management practices. The treatments consisted of harvest trash mulching, bare soil, and burned trash, all three in a ratoon crop, after first cane harvest. One transect of 84 points was sampled, meter by meter, covering all treatments and borders. The state-space approach is described in detail and the results show that soil water contents measured along the transect could successfully be estimated from water content and temperature observations made at the first neighbour.

scholarly journals Impacts of grass removal on wetting and actual water repellency in a sandy soil

2017 ◽  
Vol 65 (1) ◽  
pp. 88-98 ◽  
Author(s):  
Klaas Oostindie ◽  
Louis W. Dekker ◽  
Jan G. Wesseling ◽  
Violette Geissen ◽  
Coen J. Ritsema
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Soil Profile ◽  
Water Repellency ◽  
Bare Soil ◽  
Soil Profiles ◽  
The Impact ◽  
Water Contents ◽  
Soil Water Contents

Abstract Soil water content and actual water repellency were assessed for soil profiles at two sites in a bare and grasscovered plot of a sand pasture, to investigate the impact of the grass removal on both properties. The soil of the plots was sampled six times in vertical transects to a depth of 33 cm between 23 May and 7 October 2002. On each sampling date the soil water contents were measured and the persistence of actual water repellency was determined of field-moist samples. Considerably higher soil water contents were found in the bare versus the grass-covered plots. These alterations are caused by differences between evaporation and transpiration rates across the plots. Noteworthy are the often excessive differences in soil water content at depths of 10 to 30 cm between the bare and grass-covered plots. These differences are a consequence of water uptake by the roots in the grass-covered plots. The water storage in the upper 19 cm of the bare soil was at least two times greater than in the grass-covered soil during dry periods. A major part of the soil profile in the grass-covered plots exhibited extreme water repellency to a depth of 19 cm on all sampling dates, while the soil profile of the bare plots was completely wettable on eight of the twelve sampling dates. Significant differences in persistence of actual water repellency were found between the grass-covered and bare plots.

scholarly journals Efficient organic mulch thickness for soil and water conservation in urban areas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bing Wang ◽  
Jianzhi Niu ◽  
Ronny Berndtsson ◽  
Linus Zhang ◽  
Xiongwen Chen ◽  
...  
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Conservation ◽  
Urban Areas ◽  
Heavy Rainfall ◽  
Bare Soil ◽  
Rainfall Simulation ◽  
Organic Mulch ◽  
Arid And Semiarid

AbstractThe use of organic mulch is important for urban green applications. For urban areas in arid and semiarid regions receiving short high-intensive rainfall, rainfall characteristics, and soil slope play an important role for mulch functioning. These properties of mulch were studied. For this purpose, rainfall simulation experiments using organic mulching were conducted in Jiufeng National Forestry Park to analyze the influence of organic mulch under different slope and heavy rainfall events. The results showed that soil water content displayed a decreasing tendency with increasing mulch application. Compared to bare soil, a mulch application of 0.25 kg/m2 and 0.50 kg/m2 led to maximum soil water content and maximum runoff decrease occurred for 0.50 kg/m2 mulch. Higher application rate of mulch displayed less soil water content and greater runoff. The runoff amount and runoff generation rate decreased by 28–83% and 21–83%, respectively, as compared to bare soil. With a mulch application of 0.25–1.00 kg/m2, soil drainage accounted for 56–60% of total rainfall. Overall, an efficient mulch application was found to be 0.25–0.50 kg/m2. The results of this study are relevant for arid and semiarid urban regions that experience heavy rainfall.

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