THE EFFECT OF GROUNDWATER ON SOIL FORMATION IN A MORAINAL LANDSCAPE IN SASKATCHEWAN

1985 ◽  
Vol 65 (2) ◽  
pp. 293-307 ◽  
Author(s):  
J. J. MILLER ◽  
D. F. ACTON ◽  
R. J. ST. ARNAUD
Keyword(s):  
Groundwater Flow ◽  
Water Table ◽  
Soil Formation ◽  
Lateral Flow ◽  
Dominant Factor ◽  
Slope Position ◽  
Soluble Salts ◽  
Runoff Water ◽  
Depth To Water Table ◽  
Water Tables

The results of this study indicate the importance of groundwater flow and water table depth on the genesis, characteristics and distribution of soils within a hummocky morainal landscape. Non-saline and non-carbonated soils in upland depressions can be attributed to "depression-focused" recharge by snowmelt and snowmelt runoff in the spring, as evidenced by deep sola and/or eluvial horizons. Non-saline and carbonated soils on lower slopes adjacent to depressions are associated with local discharge and/or lateral flow from the adjacent groundwater mounds under the depressions in spring, as well as upward flow in the summer resulting from water use by phreatophytes such as willows, creating a water table depression around the slough fringes. Saline and carbonated soils at low elevations are associated with shallow and rather stable water tables, and local discharge from surrounding uplands. Soil types on uplands are more dependent on slope position and infiltration than on depth to water table or groundwater flow. Non-saline soils of different profile types occur on mid- and upper slope positions. These areas have a deep water table with mainly recharge or lateral flow occurring in the saturated zone. The infiltration of surface runoff water in upland depressions is the dominant factor influencing the distribution of soluble salts in this hummocky landscape. Key words: Water table, landscape position, recharge, discharge, soluble salts, soil genesis, morphology, carbonate soil

Soil characteristics in relation to groundwater for selected Dark Brown Chernozems in southern Alberta

2010 ◽  
Vol 90 (4) ◽  
pp. 597-610 ◽  
Author(s):  
J.J. Miller ◽  
D.S. Chanasyk
Keyword(s):  
Groundwater Flow ◽  
Groundwater Recharge ◽  
Water Table ◽  
Calcareous Soil ◽  
Soil Characteristics ◽  
Water Soluble ◽  
The Other ◽  
Slope Position ◽  
Southern Alberta ◽  
Water Tables

Limited information exists on soil characteristics in relation to groundwater for undulating morainal landscapes of the Dark Brown soil zone in western Canada. A 4-yr (1985-1988) field study was conducted in southern Alberta to investigate these relationships for selected Dark Brown Chernozems. Soil morphology, physical and chemical properties of the soil horizons, water fluxes in the saturated zone, and tritium content of shallow groundwater were determined at nine sites. Three Orthic Dark Brown Chernozemic soils occurred in groundwater recharge areas with water tables ≥1.81 m, indicating that leaching of carbonates from the B horizons was consistent with downward groundwater flow. The other three Orthic soils occurred in groundwater discharge areas, and they may have developed because of deeper (≥2.60 m) water tables. High water-soluble Na in these latter three Orthic soils suggested a sodic influence from a shallower water table sometime in the recent past. The two Calcareous Dark Brown Chernozems, and saline Calcareous Dark Brown Chernozem occurred in groundwater recharge areas. One calcareous soil at a lower slope position had a shallow (0.84-2.02 m) water table, suggesting carbonates were brought upward into the Cca horizon from the groundwater. The other calcareous soil at the upper slope position had a deeper (>6.62 m) water table, suggesting carbonates were leached downward and precipitated in the Cca horizon. The saline Calcareous Dark Brown Chernozem was located in an area of groundwater recharge with a deeper (4-9 m) water table, suggesting that salinization likely occurred sometime in the past. Groundwater flow conditions during this study could not explain the genesis of some soils in this study area, suggesting that past groundwater, climatic, and environmental conditions need to be considered to explain the genesis of some relict soils.

scholarly journals Applying MODFLOW to wet grassland in-field habitats: a casestudy from the Pevensey Levels, UK

2003 ◽  
Vol 7 (1) ◽  
pp. 43-55 ◽  
Author(s):  
R. B. Bradford ◽  
M. C. Acreman
Keyword(s):  
Groundwater Flow ◽  
Water Table ◽  
Hydrological Regime ◽  
Water Levels ◽  
Management Technique ◽  
Low Permeability ◽  
Groundwater Levels ◽  
Depth To Water Table ◽  
Wet Grasslands ◽  
Vertical Leakage

Abstract. Historical drainage improvements have created complex hydrological regimes in many low-lying, wet coastal grassland areas. The manipulation of ditch water levels is a common management technique to maintain important in-stream and in-field habitats in such areas. However, in wet grasslands with low soil conductivities the water table in the centre of each field is not closely coupled to variations in ditch stage. Consequently rainfall and evaporation have a greater influence on the depth to water table and water table fluctuations within each field. In-field micro-topographic variations also lead to subtle variations in the hydrological regime and depth to water table that create a mosaic of different wetness conditions and habitats. The depth, duration, timing and frequency of flooding from accumulated rainfall, surface water and standing groundwater also influence the availability of suitable in-field habitats. Land drainage models are often used for studies of wet grasslands, but tend to be more complex and require more field variables than saturated zone models. This paper applies a 3D groundwater flow model, MODFLOW, to simulate groundwater levels within a single field in a wet coastal grassland underlain by a low permeability sequence and located in the central part of Pevensey Levels, Sussex, UK. At this scale, the influence of vertical leakage and regional groundwater flow within the deeper, more permeable part of the sequence is likely to be small. Whilst available data were not sufficient to attempt a full calibration, it was found that the sequence could be represented as a single, unconfined sequence having uniform hydraulic properties. The model also confirmed that evaporation and rainfall are the dominant components of the water balance. Provided certain information requirements are met, a distributed groundwater model, such as MODFLOW, can benefit situations where greater hydrological detail in space and time is required to represent complex and subtle changes influencing the in-field habitats in wet grasslands with low permeability soils. Keywords: wetlands, hydrology,groundwater, MODFLOW

scholarly journals Large-scale lateral saturated soil hydraulic conductivity as metric for the connectivity of the subsurface flow paths at hillslope scale

2021 ◽  
Author(s):  
Mario Pirastru ◽  
Massimo Iovino ◽  
Hassan Awada ◽  
Roberto Marrosu ◽  
Simone Di Prima ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Spatial Scale ◽  
Water Table ◽  
Subsurface Flow ◽  
Lateral Flow ◽  
Saturated Soil ◽  
Flow Paths ◽  
Soil Hydraulic Conductivity ◽  
Hillslope Scale

Lateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes both at the hillslope and catchment scales. Likewise, the hydrological connectivity of lateral flow paths plays a significant role in determining the intensity of the subsurface flow at various spatial scales. The objective of the study is to investigate the relationship between Ks,l and hydraulic connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains, and by water table depths observed in a well network. Hydraulic connectivity of the lateral flow paths was evaluated by the synchronicity among piezometric peaks, and between the latter and the peaks of drained flow. Soil moisture and precipitation data were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. It was found that the higher was the synchronicity of the water table response between wells, the lower was the time lag between the peaks of water levels and those of the drained subsurface flow. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase of the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h-1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of the antecedent soil moisture and of the precipitation was correlated with the indicators of connectivity and with Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydraulic connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale.

Distribution, origin, and hydraulic influence of fractures in a clay-rich glacial deposit

1995 ◽  
Vol 32 (6) ◽  
pp. 957-975 ◽  
Author(s):  
L.D. McKay ◽  
J. Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
Groundwater Flow ◽  
Key Words ◽  
Water Table ◽  
Stress Relief ◽  
Fracture Density ◽  
Lacustrine Environment ◽  
Tritium Content ◽  
Glacial Deposit ◽  
A Site

In the unconsolidated clay-rich glacial deposits underlying a site in southwestern Ontario, fractures and root casts greatly influence hydraulic conductivity and groundwater flow. The fractures are predominantly vertical and have visible oxidation staining from surface to a depth of 6 m. Root casts commonly occur along fracture surfaces in the upper 3 m, but can also occur as holes in apparently unfractured blocks. The fractures are believed caused mainly by dessication during past periods of low water table. This hypothesis is supported by a decrease in fracture density with depth and the presence of a stiff crust, presumably caused by desiccation-induced consolidation. The random pebble fabric and faint layering indicate deposition in a calm lacustrine environment, which precludes the possibility of the fractures having been caused by overriding ice. Fractures were found below the depth of oxidation staining (6 m) but most of these appear to have been caused by stress-relief due to the excavation and subsequent drying. In the upper 3 m the fractures and root casts are responsible for field-measured hydraulic conductivity values that are up to 3 orders of magnitude greater than measured in the laboratory for samples of the unfractured matrix. High values of field-measured hydraulic conductivity, seasonal head variations greater than 0.5 m, and high tritium content all persist below the depth of root casts, indicating that hydraulically conductive fractures do exist to depths of at least 6 m and possibly as great as 12–15 m, which is well below the depth of oxidation staining. However, there is some uncertainty in this assessment of the extent of hydraulically conductive fractures because of the sensitivity to small leaks in the piezometer installations. Key words : clay, glacial, fractures, desiccation, hydraulic conductivity.

THE LOSS OF SOLUBLE SALTS IN RUNOFF WATER

Soil Science ◽  
1926 ◽  
Vol 21 (5) ◽  
pp. 401-409 ◽  
Author(s):  
F. L. DULEY
Keyword(s):  
Soluble Salts ◽  
Runoff Water

Effect of temporary rise of saline water table on dry matter yield of oats (Avena byzantina)

1974 ◽  
Vol 14 (71) ◽  
pp. 811 ◽  
Author(s):  
FG Abd-El-Kaddous
Keyword(s):  
Water Table ◽  
Dry Matter ◽  
Saline Water ◽  
Growth Stages ◽  
Dry Matter Yield ◽  
Water Tables ◽  
Temporary Rise ◽  
Effect On Yield ◽  
Water Table Rise ◽  
Yield Of Oats

In 1968 and 1969, at Kerang, Victoria, the dry matter yield of oats (Avena byzantina) grown on a sodic soil were measured under conditions of fluctuating saline (31 mmhos cm-1) water tables. In each year, a water table was established for 14 days at one of three growth stages and at depths varying from 7.5 to 90 cm. Relative to the yield obtained when the water table remained at 90 cm depth, dry matter yields were reduced by 70 per cent (1968) and 79 per cent (1969) by one temporary water table rise to a depth of 7.5 cm for 14 days. Intermediate reductions in yields occurred when the water tables rose temporarily to intermediate depths from 82.5 cm to 15 cm (7.5 cm intervals). The growth stage at which the water table rise occurred had no significant effect on yield, except in the second period in 1969 when yield was reduced during conditions of high temperature and low evaporation.

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