An analytical model for predicting water table dynamics during drainage and evaporation

Influence of antecedent soil moisture on hydraulic conductivity in a series of texture‐contrast soils

“…Past efforts to model subsurface lateral flow in texturecontrast soils have usually represented the impeding layer of the B2 horizons as a single uniform layer, with a single value for hydraulic conductivity (Stolte et al, 1999;Cook and Rassam, 2002;Ticehurst et al, 2003a;Ticehurst et al, 2003b). While a number of studies have simulated water movement in texture-contrast soils using either single porosity or tipping bucket models (Silberstein et al, 1999;Stolte et al, 1999;Cook and Rassam, 2002;Ticehurst et al, 2003a;Ticehurst et al, 2003b), this study has demonstrated these approaches are not suitable for simulating water and solute movement in soils that contain vertic subsoils, water repellent topsoils or soluble silica bridging such as the texture-contrast soils investigated in this study. As Silberstein et al (1999) demonstrated in the Ucarro catchment, Western Australia, inability to simulate a reduction in subsoil hydraulic conductivity resulting from seasonal swelling of texturecontrast clay subsoils resulted in inadequate simulation of seasonal perched watertables and subsurface flow.…”

“…Studies such as Cook and Rassam (2002), Hatton et al (2002), Silberstein et al (1999), Stolte et al (1999) and Ticehurst et al (2003aTicehurst et al ( , 2003b have used simulation models to better predict or understand the occurrence of perched watertables and subsurface flows in texturecontrast soils. Current modelling of subsurface lateral flows, waterlogging and solute transport in texturecontrast soils is limited by simple model conceptualisation and poor understanding of the mechanisms by which antecedent soil moisture influences hydraulic conductivity.…”

Quantification of Hydrologic Processes and Assessment of Rainfall-Runoff Models in Miami-Dade County, Florida

“…Over longer time scales, direct evapotranspiration from the water table depends on such factors as the depth to the water table, thickness of the root zone, and soil characteristics in the unsaturated zone. In many tropical areas, evaporation plays an important role in lowering the water table in finely textured soils (Cook and Rassam, 2002). In many parts of southern Florida, however, including the focus area in this study, the unsaturated zone is several feet thick and composed of a thin layer of soil overlying several feet of rock.…”

Subsurface Lateral Flow in Texture-Contrast (Duplex) Soils and Catchments with Shallow Bedrock

“…Simple conceptual understanding of subsurface lateral flow has been retained in most numerical models of water movement in texture-contrast soils. Typically, subsurface lateral flow is represented as a single flow path through the soil matrix, impeded by a layer that runs parallel to the soil surface and characterised by a single value for hydraulic conductivity, for example, Cook and Rassam [70], Stolte et al [71], Ticehurst et al [72], Smith and Hebbert [73]. This simplicity results from both limited understanding of the processes responsible for generation of subsurface lateral flow in texture-contrast soils, particularly the role of preferential flow, and lack of field data required to adequately represent the spatial and temporal variations of the soil hydraulic properties.…”