scholarly journals Role of Hydraulic Conductivity on Surface and Groundwater Interaction in Wetlands

10.5772/25170 ◽  
2011 ◽  
Author(s):  
Cevza Melek
Keyword(s):  
Hydraulic Conductivity ◽  
Surface And Groundwater

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

Assessment of the Role of Different Soil Properties on Crust Strength by Linear Regression Models

2019 ◽  
Vol 6 (04) ◽  
Author(s):  
MINAKSHI SERAWAT ◽  
V K PHOGAT ◽  
ANIL Abdul KAPOOR ◽  
VIJAY KANT SINGH ◽  
ASHA SERAWAT
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Crop Yields ◽  
Modulus Of Rupture ◽  
Silty Clay ◽  
Linear Regression Models ◽  
Wide Range ◽  
Dispersion Ratio ◽  
Crust Strength

Soil crust strength influences seedling emergence, penetration and morphology of plant roots, and, consequently, crop yields. A study was carried out to assess the role of different soil properties on crust strength atHisar, Haryana, India. The soil samples from 0-5 and 5-15 cm depths were collected from 21 locations from farmer’s fields, having a wide range of texture.Soil propertieswere evaluated in the laboratory and theirinfluence on the modulus of rupture (MOR), which is the measure of crust strength, was evaluated.The MOR of texturally different soils was significantly correlated with saturated hydraulic conductivity at both the depths. Dispersion ratio was found to decrease with an increase in fineness of the texture of soil and the lowest value was recorded in silty clay loam soil,which decreased with depth. The modulus of rupture was significantly negatively correlative with the dispersion ratio.There was no role of calcium carbonate in influencing the values of MOR of soils. Similarly,the influence of pH, EC and SAR of soil solution on MOR was non-significant.A perusal of thevalues of the correlations between MOR and different soil properties showed that the MOR of soils of Haryana are positively correlated with silt + clay (r = 0.805) followed by water-stable aggregates (r = 0.774), organic carbon (r = 0.738), silt (r = 0.711), mean weight diameter (r = 0.608) and clay (r = 0.593) while negatively correlated with dispersion ratio (r = - 0.872), sand (r = -0.801) and hydraulic conductivity (r = -0.752) of soils.

scholarly journals The role of groundwater characteristics in catchment recovery from nitrate pollution

2012 ◽  
Vol 43 (5) ◽  
pp. 560-575 ◽  
Author(s):  
S. M. Dunn ◽  
W. G. Darling ◽  
C. Birkel ◽  
J. R. Bacon
Keyword(s):  
Dispersion Model ◽  
Age Dating ◽  
Groundwater Transport ◽  
Transit Times ◽  
Groundwater Samples ◽  
Nitrate Concentrations ◽  
Groundwater Dating ◽  
Different Levels ◽  
Surface And Groundwater

The effectiveness of measures to mitigate nitrate concentrations in surface and groundwater depends not only on their suitability for reducing nitrate leaching, but also on characteristics of groundwater transport that may cause a lag in achieving recovery. The recovery of a catchment within a Nitrate Vulnerable Zone in the east of Scotland has been assessed using a combined monitoring and modelling approach. Understanding of the dominant hydrological processes was developed through a programme of monitoring of surface and groundwater bodies. Age dating of groundwater samples, using dissolved atmospheric trace gases (CFCs and SF6) underpinned the conceptualisation of groundwater transport and a lumped dispersion model was applied to the data to estimate mean solute transit times. High spatial variability in the groundwater dating made it difficult to estimate catchment means, but the range was estimated to lie between 15 and 60 years. A catchment hydrology and nitrate model was used to explore the effect of simple changes in land management on reducing nitrate concentrations, as well as associated time scales of recovery. The study has helped improve understanding of the role of groundwater in catchment recovery and given an indication of the scale of agricultural changes required to achieve different levels of pollution mitigation.

Hydraulic conductivity of bentonite-sand mixtures

2000 ◽  
Vol 37 (2) ◽  
pp. 406-413 ◽  
Author(s):  
P V Sivapullaiah ◽  
A Sridharan ◽  
V K Stalin
Keyword(s):  
Hydraulic Conductivity ◽  
Water Retention ◽  
Void Ratio ◽  
Clay Content ◽  
Liquid Limit ◽  
Natural Soils ◽  
Waste Containment ◽  
Clay Liner

The use of bentonite alone or amended with natural soils for construction of liners for water-retention and waste-containment facilities is very common. The importance of bentonite content in reducing the hydraulic conductivity of liners is well recognised. The study illustrates the role of the size of the coarser fraction in controlling the hydraulic conductivity of the clay liner. It has been shown that at low bentonite contents the hydraulic conductivity of the liner varies depending on the size of the coarser fraction apart from clay content. At a given clay content, the hydraulic conductivity increases with an increase in the size of the coarser fraction. But when the clay content is more than that which can be accommodated within the voids of the coarser fractions, the hydraulic conductivity is controlled primarily by clay content alone. Four different methods of predicting hydraulic conductivity of the liners are presented. Using two constants, related to the liquid limit, the hydraulic conductivity can be predicted at any void ratio.Key words: clays, hydraulic conductivity, liquid limit, liners, void ratio.

Enhancement of root hydraulic conductivity by methyl jasmonate and the role of calcium and abscisic acid in this process

2013 ◽  
Vol 37 (4) ◽  
pp. 995-1008 ◽  
Author(s):  
BEATRIZ SÁNCHEZ-ROMERA ◽  
JUAN MANUEL RUIZ-LOZANO ◽  
GUOWEI LI ◽  
DOAN-TRUNG LUU ◽  
MARIA DEL CARMEN MARTÍNEZ-BALLESTA ◽  
...  
Keyword(s):  
Abscisic Acid ◽  
Hydraulic Conductivity ◽  
Methyl Jasmonate ◽  
Root Hydraulic Conductivity

Role of albumin arginyl sites in albumin-induced reduction of endothelial hydraulic conductivity

1989 ◽  
Vol 141 (3) ◽  
pp. 558-564 ◽  
Author(s):  
Michael R. Powers ◽  
Frank A. Blumenstock ◽  
Jeffrey A. Cooper ◽  
Asrar B. Malik
Keyword(s):  
Hydraulic Conductivity

The role of water in the regulation of plant development

1987 ◽  
Vol 65 (7) ◽  
pp. 1287-1298 ◽  
Author(s):  
Gordon I. McIntyre
Keyword(s):  
Hydraulic Conductivity ◽  
Seed Germination ◽  
Metabolic Activity ◽  
Plant Development ◽  
Water Distribution ◽  
Stem Elongation ◽  
Cellular Level ◽  
Basic Functions ◽  
Different Parts

It is postulated that the changes in growth and metabolic activity that characterize many features of plant development are produced by the interaction between the hydraulic conductivity of the tissues and the influence of environmental factors, transpiration and osmotic gradients on the uptake, distribution, or loss of water. Mechanisms based on this concept are proposed for six aspects of development. These are (i) seed germination and stem elongation (water uptake), (ii) apical dominance and tropisms (water distribution), and (iii) leaf senescence and abscission (water loss). The postulated mechanisms are based on the hypothesis that water is the factor that normally limits the rate of growth and metabolic activity in the intact plant. The validity of the concept is supported by the unique capacity of water to perform three basic functions. These functions are (i) to mediate environmental effects on growth and metabolism, (ii) to correlate the growth of different parts of the plant, and (iii) to integrate growth and metabolic activity at the cellular level. It is also suggested that the responses induced by the application to plants of certain growth-regulating substances can be mainly attributed to the capacity of these substances to promote the uptake of water.

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