Role of Rock Heterogeneity on Lateral Diversion of Water Flow at the Soil-Rock Interface

2004 ◽  
Vol 3 (3) ◽  
pp. 786-795 ◽  
Author(s):  
N. Bockgard ◽  
A. Niemi
Keyword(s):  
Water Flow ◽  
Rock Heterogeneity ◽  
Rock Interface ◽  
Lateral Diversion

Fluid Absorption in the Kidney Proximal Tubule

Physiology ◽  
1987 ◽  
Vol 2 (1) ◽  
pp. 22-26
Author(s):  
JA Schafer
Keyword(s):  
Proximal Tubule ◽  
Water Flow ◽  
Water Permeability ◽  
Interstitial Fluid ◽  
High Water ◽  
Fluid Absorption ◽  
Humoral Factors ◽  
Solute Absorption ◽  
Leaky Epithelium

Fluid absorption in the proximal tubule can be driven by a small osmotic difference between the luminal and interstitial fluids because this leaky epithelium has a high water permeability. The osmotic difference is produced by solute absorption, which tends to dilute the luminal fluid and concentrate the interstitial fluid. However, important questions remain unanswered regarding the pathway for water flow and the role of hemodynamic and humoral factors.

Role of circulation in maintaining Na+ and K+ concentration in pelvic patch in Rana catesbeiana

1991 ◽  
Vol 261 (3) ◽  
pp. R686-R689 ◽  
Author(s):  
R. H. Parsons ◽  
R. Schwartz
Keyword(s):  
Water Flow ◽  
Water Uptake ◽  
Rana Catesbeiana ◽  
Salt Content ◽  
Ventral Surface ◽  
Bathing Medium ◽  
Pectoral Region ◽  
K Concentration ◽  
Skin Samples

Skin samples from the pelvic, pectoral, and back areas of frogs were taken from control (C) animals and from dehydrated animals under three conditions: dehydrated and not exposed to a bathing medium (D), dehydrated live and ventral surface exposed to a bathing medium (DL), and dehydrated with heart stopped and ventral surface exposed to a bathing medium (DHS). The skin concentration of Na+ and K+ of the pelvic patch in the absence of circulation was significantly reduced [DHS 286 +/- 22 microM/mg dry wt (n = 6)] compared with control [C 392 +/- 21 microM/mg dry wt (n = 8)]. However, the pelvic skin concentration was maintained in a frog with an intact circulation [DL 381 +/- 26 microM/mg dry wt (n = 7)] even in the presence of a high pelvic water flow [684 +/- 105 cm3.cm-2.s-1.10(-7) (n = 13)]. The water uptake in the pectoral region [231 +/- 54 cm3.cm-2.s-1.10(-7) (n = 13)] was not high enough to predict a dilution, and none was found. The concentrations were 354 +/- 21 (n = 8), 359 +/- 22 (n = 7), 353 +/- 26 (n = 7), and 373 +/- 45 microM/mg dry wt (n = 6) for C, D, DL, and DHS, respectively. Examination of the Na+ and K+ concentrations separately in the pelvic skin shows that the lower salt content in DHS frogs is mainly due to a loss of Na+.(ABSTRACT TRUNCATED AT 250 WORDS)

Roles of clay layers in rainfall-runoff processes in a serpentinite headwater catchment

2020 ◽  
Author(s):  
Takahiko Yoshino ◽  
Shin'ya Katsura
Keyword(s):  
Water Flow ◽  
Groundwater Level ◽  
Mineral Soil ◽  
High Water ◽  
Organic Soil ◽  
Rainfall Runoff ◽  
Soil Layers ◽  
Clay Layers ◽  
Headwater Catchment

<p>Rainfall-runoff processes in a headwater catchment have been typically explained by water flow in permeable soil layers (comprised of organic soil layers and mineral soil layers produced by weathering of bedrock) overlying less permeable layers (i.e., bedrock). In a catchment where mineral soils are characterized by clayey materials (e.g., mudstone, slate, and serpentine catchment), it is possible that mineral soil layers function substantially as less permeable layers because of a low permeability of clayey materials. However, roles of clay layers in rainfall-runoff processes in such a headwater catchment are not fully understood. In this study, we conducted detailed hydrological, hydrochemical, and thermal observations in a serpentinite headwater catchment (2.12 ha) in Hokkaido, Northern Japan, where mineral soil layers consisting of thick clay layers (thickness: approximately 1.5 m) produced by weathering of the serpentinite bedrock underlies organic soil layers (thickness: approximately 0.4 m). Saturated hydraulic conductivity (Ks) and water retention curve of these two layers were also measured in a laboratory. The observation results demonstrated that groundwater was formed perennially in the organic soil layers and clay layers. The groundwater level within the organic soil layers and specific discharge of the catchment showed rapid and flashy change in response to rainfall. In contrast, the groundwater level within the clay layers showed slow and small change. Temperature of the groundwater and stream water suggested that water from the depth of the organic soil layers contributed to streamflow. The electric conductivity (EC) of the groundwater in the clay layers was very high, ranging from 321 to 380 µS cmˉ¹. On the other hand, the EC of soil water (unsaturated water stored in the organic soil layers) was relatively low, ranging from 98 to 214 µS cmˉ¹. Hydrograph separation using EC showed that contribution of water emerging from the clay layers to the total streamflow ranged from 31 to 76% in low to high flow periods. Temporal variation in the total head, measured using tensiometers installed at four depths at the ridge of the catchment, indicated that in wet periods when the groundwater level in the organic soil layers was high, water flow from the organic soil layers to the clay layers occurred, whereas, in dry periods, water flow from the clay layers into the organic soil layers occurred. The laboratory measurements showed that the organic soil layers had high Ks (10ˉ² cm sˉ¹) and low water-holding capacity, whereas the clay layers had low Ks (10ˉ⁴ cm sˉ¹) and high water-holding capacity. It can be concluded from these results that clay layers play two roles: (1) forming perched groundwater table and lateral flow on the clay layers (the role of less permeable layers) and (2) supplying water into the organic soil layers in the dry periods (the role of water supplier).</p>

The Role of Hand Calculations in Ground Water Flow Modeling

Ground Water ◽  
2006 ◽  
Vol 44 (6 Understanding) ◽  
pp. 786-791 ◽  
Author(s):  
Henk Haitjema
Keyword(s):  
Ground Water ◽  
Water Flow ◽  
Flow Modeling ◽  
Ground Water Flow

Evidence for the role of the Ns protein in the forskolin actions on osmotic water flow

1988 ◽  
Vol 90 (4) ◽  
pp. 825
Author(s):  
V Casavola ◽  
G Valenti ◽  
G Calamita ◽  
J Bourguet ◽  
M Svelto
Keyword(s):  
Water Flow ◽  
Osmotic Water ◽  
Osmotic Water Flow

Determination of the role of entrapped air in water flow in a closed soil pipe using a laboratory experiment

2017 ◽  
Vol 31 (21) ◽  
pp. 3740-3749 ◽  
Author(s):  
Takuhei Yamasaki ◽  
Hiromi Imoto ◽  
Shoichiro Hamamoto ◽  
Taku Nishimura
Keyword(s):  
Laboratory Experiment ◽  
Water Flow ◽  
Entrapped Air ◽  
Soil Pipe
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