Evaluation of Model Complexity and Input Uncertainty of Field-Scale Water Flow and Salt Transport

2006 ◽  
Vol 5 (3) ◽  
pp. 951-962 ◽  
Author(s):  
G. Schoups ◽  
J. W. Hopmans
Keyword(s):  
Water Flow ◽  
Salt Transport ◽  
Model Complexity ◽  
Field Scale ◽  
Input Uncertainty

scholarly journals Comparison between field measurements and numerical simulation of steady-state solute transport in a heterogeneous soil profile

1997 ◽  
Vol 1 (4) ◽  
pp. 853-871 ◽  
Author(s):  
J. Vanderborght ◽  
D. Jacques ◽  
D. Mallants ◽  
P.-H. Tseng ◽  
J. Feyen
Keyword(s):  
Solute Transport ◽  
Water Flow ◽  
Random Fields ◽  
Hydraulic Properties ◽  
Soil Hydraulic Properties ◽  
Field Scale ◽  
Flow Heterogeneity ◽  
Heterogeneous Soil ◽  
Soil Hydraulic ◽  
Second Procedure

Abstract. Abstract: Field-scale solute dispersion is determined by water flow heterogeneity which results from spatial variability of soil hydraulic properties and soil moisture state. Measured variabilities of soil hydraulic properties are highly sensitive to the experimental method. Field-scale dispersion derived from leaching experiments in a macroporous loam soil was compared with field-scale dispersion obtained with numerical simulations in heterogeneous random fields. Four types of random fields of hydraulic properties having statistical properties derived from four different types of laboratory measurements were considered. Based on this comparison, the measurement method depicting heterogeneities of hydraulic properties most relevant to field-scale solute transport was identified. For unsaturated flow, the variability of the hydraulic conductivity characteristic measured on a small soil volume was the most relevant parameter. For saturated flow, simulated dispersion underestimated the measured dispersion and it was concluded that heterogeneity of macroscopic hydraulic properties could not represent solute flow heterogeneity under these flow conditions. Field-scale averaged solute concentrations depend both on the detection method and the averaging procedure. Flux-averaged concentrations (relevant to practical applications) differ from volume-averaged or resident concentrations (easy to measure), especially when water flow is more heterogeneous. Simulated flux and resident concentrations were subsequently used to test two simple one-dimensional transport models in predicting flux concentrations when they are calibrated on resident concentrations. In the first procedure, solute transport in a heterogeneous soil is represented by a 1-D convection dispersion process. The second procedure was based on the relation between flux and resident concentrations for a stochastic convective process. Better predictions of flux concentrations were obtained using the second procedure, especially when water flow and solute transport are very heterogeneous.

Water flow and salt transport in cracking clay soils of the Imperial Valley, California

2007 ◽  
Vol 20 (4) ◽  
pp. 361-387 ◽  
Author(s):  
W. W. Wallender ◽  
K. K. Tanji ◽  
J. R. Gilley ◽  
R. W. Hill ◽  
J. M. Lord ◽  
...  
Keyword(s):  
Water Flow ◽  
Salt Transport ◽  
Clay Soils ◽  
Imperial Valley

Parameterization of two‐dimensional approaches in HYDRUS‐2D: Part 1. Simulating water flow dynamics at the field scale

2021 ◽  
Author(s):  
Ioannis Varvaris ◽  
Zampela Pittaki‐Chrysodonta ◽  
Christen Duus Børgesen ◽  
Bo V. Iversen
Keyword(s):  
Water Flow ◽  
Flow Dynamics ◽  
Two Dimensional ◽  
Field Scale

scholarly journals Version 1 of a sea ice module for the physics-based, detailed, multi-layer SNOWPACK model

2020 ◽  
Vol 13 (1) ◽  
pp. 99-119 ◽  
Author(s):  
Nander Wever ◽  
Leonard Rossmann ◽  
Nina Maaß ◽  
Katherine C. Leonard ◽  
Lars Kaleschke ◽  
...  
Keyword(s):  
Grain Size ◽  
Sea Ice ◽  
Mass Balance ◽  
Weddell Sea ◽  
Salt Transport ◽  
Model Complexity ◽  
Richards Equation ◽  
Size And Shape ◽  
Ice Mass Balance ◽  
Grain Size And Shape

Abstract. Sea ice is an important component of the global climate system. The presence of a snowpack covering sea ice can strongly modify the thermodynamic behavior of the sea ice, due to the low thermal conductivity and high albedo of snow. The snowpack can be stratified and change properties (density, water content, grain size and shape) throughout the seasons. Melting snow provides freshwater which can form melt ponds or cause flushing of salt out of the underlying sea ice, while flooding of the snow layer by saline ocean water can strongly impact both the ice mass balance and the freezing point of the snow. To capture the complex dynamics from the snowpack, we introduce modifications to the physics-based, multi-layer SNOWPACK model to simulate the snow–sea-ice system. Adaptations to the model thermodynamics and a description of water and salt transport through the snow–sea-ice system by coupling the transport equation to the Richards equation were added. These modifications allow the snow microstructure descriptions developed in the SNOWPACK model to be applied to sea ice conditions as well. Here, we drive the model with data from snow and ice mass-balance buoys installed in the Weddell Sea in Antarctica. The model is able to simulate the temporal evolution of snow density, grain size and shape, and snow wetness. The model simulations show abundant depth hoar layers and melt layers, as well as superimposed ice formation due to flooding and percolation. Gravity drainage of dense brine is underestimated as convective processes are so far neglected. Furthermore, with increasing model complexity, detailed forcing data for the simulations are required, which are difficult to acquire due to limited observations in polar regions.

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