Experimental evaluation of different subsurface water movement models in an agricultural field with soil heterogeneity

2021 ◽  
Vol 599 ◽  
pp. 126298
Author(s):  
Ephrem Yetbarek ◽  
Richa Ojha
Keyword(s):  
Experimental Evaluation ◽  
Water Movement ◽  
Soil Heterogeneity ◽  
Subsurface Water ◽  
Agricultural Field ◽  
Movement Models

scholarly journals Water and nitrate movements in an agricultural field with different soil frost depths: field experiments and numerical simulation

2013 ◽  
Vol 54 (62) ◽  
pp. 157-165 ◽  
Author(s):  
Yukiyoshi Iwata ◽  
Tomotsugu Yazaki ◽  
Shinji Suzuki ◽  
Tomoyoshi Hirota
Keyword(s):  
Field Experiments ◽  
Water Movement ◽  
Snow Accumulation ◽  
Control Plot ◽  
Soil Freezing ◽  
Nitrate Content ◽  
Agricultural Field ◽  
Snowmelt Period ◽  
Frost Depth ◽  
Treated Plot

AbstractTo evaluate water and anion movement in an agricultural field in different frost conditions, a paired-plot field experiment was conducted at an agricultural site in northern Japan where a significant decrease in the frost depth has occurred during the past 20 years. Snow cover was removed to enhance soil freezing in one plot (treated plot), whereas natural conditions were maintained in a control plot. The maximum frost depth was 0.43 m in the treated plot and 0.11 m in the control plot, which induced substantial differences in water movement throughout the winter. A substantial amount of water moved upward before the onset of snowmelt. However, nitrate did not move markedly before the snowmelt period in either plot. The amount of snowmelt infiltration in the control plot was larger than in the treated plot. Correspondingly, the peak of nitrate content in the control plot was deeper than that in the treated plot after the snowmelt period. Soil freezing, snow accumulation and snowmelt processes were simulated reasonably well using a one-dimensional numerical model: Simultaneous Heat and Water (SHAW). Nevertheless, the model performed poorly for simulating soil thawing and soil water movement, suggesting a need for improvement.

The nature and extent of bomb tritium remaining in deep soils

2021 ◽  
Author(s):  
Jaivime Evaristo ◽  
Yanan Huang ◽  
Zhi Li ◽  
Kwok P. Chun ◽  
Edwin H. Sutanudjaja ◽  
...  
Keyword(s):  
Water Movement ◽  
Subsurface Water ◽  
Arid Environments ◽  
Nuclear Bomb ◽  
Bomb Test ◽  
The 1960S ◽  
Environmental Tritium ◽  
Test Ban ◽  
Deep Soils ◽  
Made In

<p>Understanding the movement of water in soils is important for estimating subsurface water reserves. Despite the advances made in understanding water movement, very few tools can directly ‘follow the water’. Tritium, a tracer that decays with time and resides within individual water molecules, is one such tool. Some tritium is produced naturally, others result from the nuclear bomb test era of the 1960s. Since the atmospheric nuclear tests ended following the Partial Nuclear Test Ban Treaty in 1963, however, the amount of tritium in soil water has declined, putting into question the usefulness of the environmental tritium method for tracking water movement in future studies. Our study explores the usefulness of the tritium method. Our results highlight the narrow window of time, over the next 20 years depending on the model used, within which the tritium method may still be applicable. We call on scientists to now take full advantage of the environmental tritium method in places where the tool may still be applicable. A richer understanding of water movement in soils is ultimately critical for ecosystem services and water resources management, particularly in semi-arid environments with deep soils.</p>

scholarly journals Improving the Representation of Subsurface Water Movement in Land Models

2019 ◽  
Vol 20 (12) ◽  
pp. 2401-2418 ◽  
Author(s):  
Shervan Gharari ◽  
Martyn P. Clark ◽  
Naoki Mizukami ◽  
Jefferson S. Wong ◽  
Alain Pietroniro ◽  
...  
Keyword(s):  
Temporal Variability ◽  
Preferential Flow ◽  
Water Movement ◽  
Model Simulation ◽  
Spatial Scales ◽  
Added Value ◽  
Subsurface Water ◽  
Richards Equation ◽  
Model Parameters ◽  
Moisture Movement

Abstract Land models are increasingly used and preferred in terrestrial hydrological prediction applications. One reason for selecting land models over simpler models is that their physically based backbone enables wider application under different conditions. This study evaluates the temporal variability in streamflow simulations in land models. Specifically, we evaluate how the subsurface structure and model parameters control the partitioning of water into different flow paths and the temporal variability in streamflow. Moreover, we use a suite of model diagnostics, typically not used in the land modeling community to clarify model weaknesses and identify a path toward model improvement. Our analyses show that the typical land model structure, and their functions for moisture movement between soil layers (an approximation of Richards equation), has a distinctive signature where flashy runoff is superimposed on slow recessions. This hampers the application of land models in simulating flashier basins and headwater catchments where floods are generated. We demonstrate the added value of the preferential flow in the model simulation by including macropores in both a toy model and the Variable Infiltration Capacity model. We argue that including preferential flow in land models is essential to enable their use for multiple applications across a myriad of temporal and spatial scales.

scholarly journals Coupled model of surface runoff and surface-subsurface water movement

2020 ◽  
Vol 137 ◽  
pp. 103499
Author(s):  
Zhuangji Wang ◽  
Dennis Timlin ◽  
Mikhail Kouznetsov ◽  
David Fleisher ◽  
Sanai Li ◽  
...  
Keyword(s):  
Surface Runoff ◽  
Water Movement ◽  
Coupled Model ◽  
Subsurface Water

Raman spectroscopy of the Dukhan sabkha: identification of geological and biogeological molecules in an extreme environment

2010 ◽  
Vol 368 (1922) ◽  
pp. 3099-3107 ◽  
Author(s):  
Howell G. M. Edwards ◽  
Fadhil Sadooni ◽  
Petr Vítek ◽  
Jan Jehlička
Keyword(s):  
Spectroscopic Analysis ◽  
Water Movement ◽  
Extreme Environment ◽  
Subsurface Water ◽  
Martian Surface ◽  
Raman Spectroscopic ◽  
Future Space ◽  
Extreme Salinity ◽  
The Persian Gulf

The characterization of minerals and biogeological deposits in a terrestrial Arabian sabkha has a direct relevance for the exploration of Mars since the discovery by the NASA rovers Spirit and Opportunity of evaporate minerals on Mars that could have arisen from aquifers and subsurface water movement. The recognition of carbonates and sulphates in Gusev Crater has afforded an additional impetus to these studies, as relict or extant microbial extremophilic organisms could have colonized these geological matrices, as has been recorded on Earth. Here, we describe the Raman spectroscopic analysis of specimens of evaporitic materials sampled from the Dukhan sabkha, the largest inland sabkha in the Persian Gulf. With daily temperatures reaching in excess of 60 ° C and extreme salinity, we have identified the characteristic Raman signatures of key biomolecular compounds in association with evaporitic minerals and geological carbonate and sulphate matrices, which indicate that extremophilic cyanobacterial colonies are existent there. This evidence, the first to be acquired spectroscopically from such a region, establishes a platform for further studies using remote, portable Raman instrumentation that will inform the potential of detection of similar systems on the Martian surface or subsurface in future space missions. A comparison is made between the results from this study and the previous analysis of a gypsum/halite sabkha where the extremophilic molecular signatures were better preserved.

scholarly journals Modeling Unsaturated Zone Water Movement in the Floodplain Wetlands of the Volta Basin

2020 ◽  
Vol 10 (3) ◽  
pp. 1
Author(s):  
Benjamin Kofi Nyarko
Keyword(s):  
Unsaturated Zone ◽  
Water Movement ◽  
High Surface ◽  
Water System ◽  
Hydraulic Head ◽  
Subsurface Water ◽  
Floodplain Wetlands ◽  
Volta Basin ◽  
High Dependency ◽  
Spatio Temporal

The unsaturated zone of floodplain wetlands in the White Volta River basin provides an inextricable link between basin hydrology and the sustenance of plant growth. The HYDRUS-1D model was used to derive water budgets and to estimate fluxes to understand the hydrological complexities of these wetland systems. The model result indicates Spatio-temporal variation in the volume of vertical fluxes. In 2005, the estimate for average simulated flux was 0.29 cm/month in June and 1.23 cm/month in July. Consequently, the hydraulic head increased from 138.94 m to 139.30 m for the period from June to July 2005. For all sample sites, the increase in hydraulic head occurs within July and October, coinciding with high surface water fluxes. From the calculated water balance, the average monthly estimate of bottom flux was 0.01 cm/month for 2004 and 1.1 cm/month for 2005. The flow through the unsaturated zone and discharging into the subsurface water system has a high dependency on both the soil structure and the volume of water infiltrating through the surface; the highest discharge is within the period of highest water input.

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