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Hydraulic conductivity - Wikipedia, the free encyclopedia Hydraulic conductivity is the proportionality constant in Darcy's law, which relates the amount of water which will flow through a unit cross-sectional area of aquifer under a unit gradient of hydraulic head. The hydraulic conductivity (k — the English letter "kay") is specific to the flow of a certain fluid (typically water, sometimes oil or air); intrinsic permeability (κ — the Greek letter "kappa") is a parameter of a porous media which is independent of the fluid. Hydraulic conductivity has units with dimensions of length per time (e.g., m/s, ft/day and gal/(day/ft²)); transmissivity then has units with dimensions of length squared per time. en.wikipedia.org /wiki/Hydraulic_conductivity   (607 words)

[No title] The hydraulic conductivity of a soil is a measure of the soil's ability to transmit water when submitted to a hydraulic gradient. The hydraulic conductivity depends on the soil grain size, the structure of the soil matrix, the type of soil fluid, and the relative amount of soil fluid (saturation) present in the soil matrix. The saturated hydraulic conductivity is then evaluated as a function of the geometrical dimension of the cavity in the piezometer tube, the dimensions of the aquifer, and the measured rate of rise of the water table in the tube. web.ead.anl.gov /resrad/datacoll/conuct.htm   (5000 words)

SOFIA - WRI Report 90-4108 - Hydrogeology - Hydraulic Conductivity Distribution and Hydraulic Conductivity of the ... Tests conducted during this investigation (table 5) and other studies (table 3 and table 4) indicate the average hydraulic conductivity of the Fort Thompson Formation over most of the area is tens of thousands of feet per day, possibly exceeding an average of 40,000 ft/d. The hydraulic conductivity of the semiconfining unit generally is low to moderate because silty or clayey sand and relatively clean sand, sometimes partly cemented, are the most common lithologies. This is consistent with drilling data, which indicate a general decrease in hydraulic conductivity and transmissivity from west to east in the aquifer in western Dade County. sofia.usgs.gov /publications/wri/90-4108/wdade.html   (1800 words)

Saturated Hydraulic Conductivity: Water Movement Concepts and Class History| NRCS Soils Hydraulic conductivity (K) is the constant that defines the proportionate relationship of flux to hydraulic gradient. Water moves from points of higher to lower total hydraulic head regardless of whether the points are in a soil core (as in figure 2) or in a soil landscape. In summary, flux is a rate (the dependent variable in figure 3), hydraulic gradient is the driving force behind flux (the independent variable in figure 3), and hydraulic conductivity is the proportionality constant that defines the relationship between the two. soils.usda.gov /technical/technotes/note6.html   (3748 words)

Software from ACPA It is expected that prediction of soil water retention and unsaturated hydraulic conductivity data from basic soil properties can be improved if hydraulic data are determined using a single measurement method that is consistently applied to all soil samples. Using neural network analysis, soil water retention and hydraulic conductivity characteristics are predicted from basic soil properties, i.e., sand, silt, and clay content, bulk density, saturated water content, and saturated hydraulic conductivity. Unsaturated hydraulic conductivity predictions improved significantly when the performance-based algorithm was used, minimizing residuals of soil hydraulic data rather than hydraulic parameters. www.usyd.edu.au /su/agric/acpa/software/multistep.htm   (255 words)

SOFIA - WRI Report 87-4034 - Hydrogeology - Hydraulic Conductivity Framework and Hydraulic Conductivity of the ... A major transition on the geology, and consequently, the hydraulic conductivity framework of Broward County occurs in the vicinity of the boundary between west and central Broward County. Although the extent of this shell sand is not known, it may be in hydraulic continuity laterally with part of the gray limestone aquifer to the south or north and presently included in that aquifer (fig. The average vertical hydraulic conductivity of this sand zone is less than the horizontal hydraulic conductivity, especially at the north Dixie well field where there are many thin layers of silt, siltstone, and greenish limestone of low permeability. sofia.usgs.gov /publications/wri/87-4034/cebroward.html   (2306 words)

Digital data sets that describe aquifer characteristics of the Enid isolated terrace aquifer in northwestern Oklahoma Hydraulic conductivities reported in the ground-water modeling thesis and report for the Enid isolated terrace aquifer are 93.6 feet per day and 134 feet per day. The hydraulic conductivity polygons shown on figure 14 of the ground-water modeling report, "A ground-water management model for the Enid isolated terrace aquifer in Garfield County, Oklahoma," by Beausoleil (1981) were transferred to a plate from the report and digitized. The hydraulic conductivity polygons were digitized from a photocopy of a paper map (19.0 inches by 17.5 inches) with a maximum registration root-mean-squared-error (RMSE) of 0.008 map inches (0.020 map centimeters) and 42.7 feet (13 meters) ground distance. water.usgs.gov /GIS/metadata/usgswrd/XML/ofr96-450_cond.xml   (1866 words)

SOFIA - Application of ground-penetrating radar, digital optical borehole images, and cores for characterization of ... The HFC with the higher porosity and hydraulic conductivity values is shown as a discrete package of relatively low-amplitude reflections, whereas the HFC characterized by lower porosity and hydraulic-conductivity measurements is expressed by higher amplitude reflections. Hydraulic conductivity is also highest at the base of the peritidal cycles and lowest in the middle to upper parts of cycles. This change in porosity and hydraulic conductivity from bottom to top is visible as an upward variation in reflection amplitude on GPR profiles-lowest amplitudes at the base and highest at the cycle tops. sofia.usgs.gov /publications/papers/hc_paleokarst/index.html   (595 words)

Soil Hydraulic Conductivity Data (FIFE) The constant well head method for hydraulic conductivity involves augering a hole to the desired depth and measuring the steady state flow rate of water into the hole while maintaining a constant head of water inside the hole. The hydraulic conductivity measurements were made at the same depths and close to (< 1 m away from) the location where samples for moisture release measurements were taken. Hydraulic conductivity was calculated as described in the Derivation Techniques and Algorithms Section. www-eosdis.ornl.gov /FIFE/Datasets/Soil_Properties/Soil_Hydraulic_Conductivity_Data.html   (3100 words)

AGVISE Laboratories -- Unsaturated Hydraulic Conductivity Unsaturated Hydraulic Conductivity is one of the soil parameters recommended on ground water studies by government agencies. Unsaturated hydraulic conductivity is a measure of how water flows through a soil profile when the soil is not saturated with water. The unsaturated hydraulic conductivity of a soil is important when evaluating the movement of pesticides and nutrients through the soil at different water contents. www.agviselabs.com /tech_art/unsathy.php   (422 words)

Hydraulic Conductivity Hydraulic conductivity is a soil property that describes the ease with which the soil pores permit water (not vapor) movement. where Ksat is the saturated hydraulic conductivity, A is the cross-sectional area of the column through which the water flows, DP is the hydrostatic pressure difference from the top of the column to the bottom of the column, and L is the length of the column. Hydraulic conductivity is an important soil property when determining the potential for widespread groundwater contamination by a contaminating source. ecorestoration.montana.edu /mineland/guide/analytical/physical/hydraulic.htm   (437 words)

SOFIA - Understanding and Predicting Global Climate Change Impacts on the Vegetation and Fauna of Mangrove Forested ... Empirical soil hydraulic conductivity (K) for the mangrove peat soil is needed for hydrologic modeling efforts such as "The Tides and Inflows in the Mangroves of the Everglades" (TIME). The hydraulic conductivity K samples were taken along a 300-meter transect, perpendicular to the south Harney riverbank through a mixed mangrove riparian forest and ending in a freshwater sawgrass prairie. Hydraulic conductivity K measurements were observed in shallow peat holes (15 cm) at five equally spaced sample sites (60 m) from the river edge. sofia.usgs.gov /projects/gcc_impacts/abstract-agu02.html   (423 words)

hydraulic action - Hutchinson encyclopedia article about hydraulic action   (Site not responding. Last check: 2007-11-03) Hydraulic action occurs as a river tumbles over a waterfall to crash onto the rocks below. The hydraulic action of ocean waves and turbulent currents forces air into rock cracks, and therefore brings about erosion by cavitation. In coastal areas hydraulic action is often the most important form of erosion. encyclopedia.farlex.com /hydraulic+action   (173 words)

Colorado Springs Proceedings - Section C - Hess The spatial variability of metal-ion adsorption and hydraulic conductivity was assessed from the results of laboratory experiments on 375 sediment samples collected from 14 boreholes in a glacial outwash, sand and gravel aquifer on Cape Cod, Massachusetts. Hydraulic conductivity was estimated on the basis of grain-size distributions. Similar vertical correlation scales were determined in an earlier study of the variability of hydraulic conductivity measured by use of permeameter and flowmeter tests. toxics.usgs.gov /pubs/cos-procee/sec.c-cape.cod/hess.final.html   (294 words)

Movement of Water: Basics of Soil-Water Relationships - Part III The hydraulic head (H) at a given point in the soil is equal to the sum of the gravitational and pressure heads, at that point, as illustrated schematically in Figure 1 for selected conditions. "Hydraulic conductivity" (K) is a measure of this ability of a soil to transmit water. Soil-water characteristic curves and hydraulic conductivity curves are needed to describe flow of water in soils. edis.ifas.ufl.edu /scripts/htmlgen.exe?DOCUMENT_SS110   (1405 words)

Hydraulic conductivity: Facts and details from Encyclopedia Topic   (Site not responding. Last check: 2007-11-03) Hydraulic conductivity is the proportionallity constant in Darcy's law Darcy\'s law quick summary: The hydraulic conductivity (k — the English letter[Follow this hyperlink for a summary of this subject] "kay") is specific to the flow of a certain fluid (typically water, EHandler: no quick summary. An aquifer test is conducted to evaluate an aquifer by "stimulating" the aquifer through constant pumping, and observing the aquifers "response" (drawdown) in... www.absoluteastronomy.com /encyclopedia/h/hy/hydraulic_conductivity.htm   (1791 words)

SOFIA - WRI Report 87-4034 - Hydrogeology - Hydraulic Conductivity Framework and Hydraulic Conductivity of the ... The hydraulic conductivity framework (permeability distribution) of the surficial aquifer system is portrayed by superimposing ranges of hydraulic conductivities on the eight geologic sections prepared by Causarás (1985). The range of hydraulic conductivities of the materials that make up the surficial aquifer system is about seven orders of magnitude–from more than 10,000 ft/d for the more permeable cavernous zones to about 0.001 ft/d or less for dense green clay. For the hydraulic conductivity sections, this range is divided into five categories, and general lithologies are shown in table 7. search.usgs.gov /highlight/cs.html?url=http%3A//sofia.usgs.gov/publications/wri/87-4034/hydrogeology.html&fterm=%22Hydraulic&la=en&charset=iso-8859-1&qt=%22Hydraulic&col=top2000+usgs&n=8&search=../query.html%3Fcharset%3Diso-8859-1%26col%3Dtop2000%2Busgs%26qt%3D%2522Hydraulic   (846 words)

Three-region Campbell Model for Unsaturated Hydraulic Conductivity in Undisturbed Soils -- Poulsen et al. 66 (3): 744 ... ) and the TRC hydraulic conductivity parameters (ß Hydraulic conductivity prediction accuracy for 100 soils (2504 measurements) from the UNSODA database (Leji et al., 1996) for the Campbell (1974), the Poulsen et al. hydraulic conductivity in undisturbed soils in the macropore soil.scijournals.org /cgi/content/full/66/3/744   (3665 words)

WRRI Template   (Site not responding. Last check: 2007-11-03) This study was conducted to determine the rates at which water and solute move along the fractures in both quartz veins and in saprolite matrix. The saprolite was saturated, hydraulic conductivity was measured in situ for each drainfield, and a bromide tracer and dye (to stain water-conducting macropores, or root channels) were applied for a specific time period. Undisturbed cores were not considered reliable for hydraulic conductivity measurements because they produced variable results due to sample disturbance and their small size which did not contain representative numbers of macropores. www2.ncsu.edu /ncsu/wrri/reports/report296.html   (414 words)

Laboratory and Field Hydraulic Conductivity of Three Compacted Paper Mill Sludges   (Site not responding. Last check: 2007-11-03) Hydraulic conductivities of three compacted paper mill sludges were measured in various ways to assess their viability for use in barrier layers in landfill final covers. Field tests conducted on barrier layers constructed with two of the sludges showed that field hydraulic conductivities can be obtained that are similar to those measured on laboratory compacted specimens prepared at the same molding water content. Additional tests showed that freezing increased the hydraulic conductivity of two of the sludges, regardless of whether the sludges were permeated between freeze-thaw cycles or only after the last thaw. www.pubs.asce.org /WWWdisplay.cgi?9702718   (334 words)

SOFIA - WRI Report 90-4108 - Hydrogeology - Hydraulic Conductivity Distribution and Hydraulic Conductivity of the ... The hydraulic conductivities of the geologic units that compose the surficial aquifer system range over seven orders of magnitude; from more than 10,000 ft/d for highly permeable limestones to about 0.001 ft/d or less for dense, green clay. For the hydraulic conductivity sections, this range is divided into five categories, and general lithologies are given in table 6. Sediments that have moderate hydraulic conductivities (10-100 ft/d) are considered the lower limit of those that may be useful for water supply, such as for domestic purposes. search.usgs.gov /highlight/cs.html?url=http%3A//sofia.usgs.gov/publications/wri/90-4108/hydrogeology.html&fterm=%22Hydraulic&la=en&charset=iso-8859-1&qt=%22Hydraulic&col=top2000+usgs&n=7&search=../query.html%3Fcharset%3Diso-8859-1%26col%3Dtop2000%2Busgs%26qt%3D%2522Hydraulic   (766 words)

The Effect of Variability in Hydraulic Conductivity on Contaminant Transport through Soil–Bentonite Cutoff Walls   (Site not responding. Last check: 2007-11-03) The advection–diffusion equation was used to investigate the impact of log-normal variation in hydraulic conductivity on both steady-state and transient contaminant flux through a cutoff wall with idealized initial and boundary conditions. The results demonstrate that contaminant flux through cutoff walls increases as the variability in hydraulic conductivity increases while all other variables are held constant, including the area-weighted average conductivity. In this case, the increase in total outward flux due to variability of hydraulic conductivity occurs because the increase in inward advective flux in areas where the seepage velocity is higher than average is more than offset by the increase in outward diffusive flux in areas where the seepage velocity is lower than average. www.pubs.asce.org /WWWdisplay.cgi?0524056   (239 words)

GroundwaterSoftware.com - July 2004 Newsletter: GroundWater Vistas 4 Hydraulic conductivity is a function of properties of the porous media and the fluid passing through it. Since hydraulic conductivity varies over such a large range, it implies, in practical terms, that order-of-magnitude knowledge is useful, and considerably greater precision is probably of little significance. As previously mentioned, hydraulic conductivity is a function of properties of the porous media and the fluid passing through it. www.groundwatersoftware.com /newsletter/july04/index.htm   (794 words)

Surface Water-Ground Water Interactions Along the Dungeness River and Vertical Hydraulic Conductivity of Streambed ...   (Site not responding. Last check: 2007-11-03) Vertical hydraulic gradients in mini-piezometers generally were negative between river miles 11.8 and 3.6, indicating loss of water from the river to ground, with the loss decreasing in the downstream direction. Vertical hydraulic gradients in the mini-piezometers generally were negative between river miles 11.8 and 3.6, indicating loss of water from the river to ground water. Vertical hydraulic conductivity of riverbed sediments was estimated using hydraulic gradients measured with the mini-piezometers and estimated seepage fluxes. www.ecy.wa.gov /biblio/0203027.html   (530 words)

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