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ScienceDaily: Sustainability Articles Infiltration is the process by which water on the ground surface enters the soil. Infiltration is governed by two forces, gravity, and capillary action. Forestry is the art, science, and practice of studying and managing forests and plantations, and related natural resources. www.sciencedaily.com /articles/earth_climate/sustainability   (510 words)

Infiltration: Hydrology   (Site not responding. Last check: 2007-10-21) Infiltration is the rate at which water is absorbed by the subsurface. Using an infiltrometer, it is possible to calculate the relative volume of water that enters the subsurface over time, measured in cm/s. The infiltration capacity and depression storage capacity are calculated under the assumption of constant precipitation, and when the capacity of depression storage is exceeded, overland flow- runoff- will occur. envstudies.brown.edu /classes/es192/2003/woon/infiltration.htm   (293 words)

Hydrology - MSN Encarta   (Site not responding. Last check: 2007-10-21) Hydrology, scientific study of the waters of the Earth, including their occurrence, distribution in space and time, and their relation to people and the natural environment. Hydrology studies all aspects of the movement of water on the surface of the Earth and within the underlying soil and rocks. Hydrology overlaps with the scientific study of water in the oceans and atmosphere, but these are primarily the responsibility of oceanography and meteorology. uk.encarta.msn.com /encyclopedia_761560096/Hydrology.html   (863 words)

EJGE paper 2005 - 0614 The rate of water infiltration into the soil and its effect on suction is expected to be influence by the types of surface cover, as well soil porosity/weathering grades, and angle of the soil slopes. Infiltrated water must be quantified and subtracted from the surface runoff in flood prediction studies and surface water management. The higher the soil infiltration rate, as in the case of soil of weathering grade III, the lower was the factor of safety against instability of the slope. www.ejge.com /2005/Ppr0614/Ppr0614.htm   (2369 words)

EPA GWERD Software - Infiltration Models Descriptions The commonly used semi-emperical infiltration model in the fields of soil physics and hydrology is the SCS Model. In this stage of infiltration the gravity component, represented by the second term of the model/equation, is negligible. Infiltration and exfiltration as described in this application assumes the soil medium to be effectively semi-infinite and the internal soil water content at the beginning of each storm event and inter-storm period is assumed to be uniform at its' long-term and space-time average. www.epa.gov /ada/csmos/infiltration/infil_desc.html   (852 words)

The Effect of Grazing Intensity on Rangeland Hydrology Collection of infiltration, runoff, and erosion data is achieved through the use of a rainfall simulator and single-ring infiltrometer. Infiltration measurements were typically recorded for a period of five to six hours during a single run. The infiltration rates are expressed as an average value for each treatment fit to a model that describes the infiltration rate over time. www.ag.ndsu.nodak.edu /streeter/2001report/Chad_engels.htm   (1993 words)

How an Increase or Reduction in Juniper Cover Alters Rangeland Hydrology The primary avenues of inflow (precipitation), transit (interception, stemflow, overland flow, infiltration, percolation) and outflow (evap-oration, transpiration, runoff, deep drainage) of water movement are outlined in Fig. Infiltration rate is dependent on a variety of vegetation factors, especially type and amount of vegetation present. The increased erosion was attributed to decreased infiltration caused by hydrophobic (water-repellant) soils. texnat.tamu.edu /symposia/juniper/TOM2.htm   (6721 words)

Water Cycle Hydrology, therefore, is a broad science that utilizes information from a wide range of other sciences and integrates them to quantify the movement of water. Hydrology, therefore, is one of the interdisciplinary sciences that is the basis for water resources development and water resources management. Infiltration is the physical process involving movement of water through the boundary area where the atmosphere interfaces with the soil. www.nwrfc.noaa.gov /info/water_cycle/hydrology.cgi   (4044 words)

hydrology. The Columbia Encyclopedia, Sixth Edition. 2001-05 Hydrology is principally concerned with the part of the cycle after the precipitation of water onto the land and before its return to the oceans; thus meteorology and oceanography are closely related to hydrology. Hydrology is also important to the study of water pollution, especially of groundwater and other potable water supplies. Knowledge of hydrology is extensively used to determine the movement and extent of contamination from landfills, mine runoff, and other potentially contaminated sites to surface and subsurface water. www.bartleby.com /65/hy/hydrolog.html   (297 words)

Impervious Surfaces Infiltration maintains the natural hydrology and biology of the watershed, especially the headwaters. When infiltration is not allowed to occur, a small stream may carry little or no water when it is not raining because there is so little stored groundwater to provide continuous flow. Infiltration allows large quantities of water to be stored in the ground and released slowly - long after the storm passes. www.hillsdalecounty.info /planningeduc0004.asp   (1106 words)

Hydrology Primer Hydrology has evolved as a science in response to the need to understand the complex water systems of the earth and help solve water problems. Hydrology is the science that encompasses the occurrence, distribution, movement and properties of the waters of the earth and their relationship with the environment within each phase of the hydrologic cycle. The hydrologic cycle is a continuous process by which water is purified by evaporation and transported from the earth's surface (including the oceans) to the atmosphere and back to the land and oceans. ut.water.usgs.gov /infores/hydrology.primer.html   (2237 words)

Basic Ground Water Hydrology The amount of precipitation that infiltrates, versus the amount that flows across the surface, varies depending on factors such as the amount of water already in the soil, soil composition, vegetation cover and degree of slope. Infiltration, however, moves under the force of gravity through the soil. As described earlier, how much water infiltrates depends on vegetation cover, slope, soil composition, depth to the water table, the presence or absence of confining beds and other factors. www.issaquah.org /comorg/gwac/Hydro.htm   (2054 words)

Cleveland State University || Environmental Institute Infiltration is not difficult to measure at a point, although the typical use of double ring infiltrometers is time consuming and labor intensive. Indeed conventional infiltration measurements made near the campus of the University of Iowa showed saturated hydraulic conductivities measured over a spatial scale of just 10 meters varied by more than an order of magnitude. Valve switch times are recorded from the microprocessor's real-time clock, allowing the infiltration rate to be determined by computing the rate at which the water depth falls. www.csuohio.edu /ei/research/hydrology.html   (672 words)

Evaluation of Best Management Practices Language: English Descriptors: Texas; Clay loam soils; Infiltration; Chiselling; Dikes; Furrows; Ponding; Rain; Impact; Kinetic energy; Surface layers; Crusts; Hydraulic conductivity; Water conservation Abstract: Chisel tillage and furrow dikes (small earthen dams constructed in the furrow) are commonly used to increase infiltration and soil water storage in semiarid regions. Infiltration rate (IR) and cumulative infiltration (CI) into an Olton day loam (fine, mixed, thermic Aridic Paleustoll) were measured by applying water at 65 and 80 mm h-1 for 1 h using a rotating- disk-type rainfall simulator. Infiltration rate at the end of water application was lower with raindrop impact than when raindrop impact was eliminated; however, there were no differences in the final IR between the initially crusted and uncrusted soils. www.nal.usda.gov /afsic/AFSIC_pubs/qb93-66.htm   (15969 words)

EPA GWERD Software - Infiltration Models Soil water infiltration is controlled by the rate and duration of water application, soil physical properties, slope, vegetation, and surface roughness. On the other hand, if water is applied slowly, the infiltration rate may be smaller than the soil infiltrability, and the supply rate becomes a determining factor for the infiltration rate. However, once the infiltration rate exceeds the soil infiltrability it is the latter which determines the actual infiltration rate, and thus the process becomes profile controlled. www.epa.gov /ada/csmos/ninflmod.html   (995 words)

Geography 327-- Soil water infiltrating water is marked by a wetting front that is diffuse in clay (due to capillarity) and sharp in sand infiltrated water seeps through the zone of aeration as belts of gravity water corresponding to precipitation or snow melt events infiltration and redistribution of soil water involve unsaturated flow in porous media, i.e. uregina.ca /~sauchyn/geog327/soil.html   (1161 words)

expertwitness.com - (hydrology) - hydrology specialists, experts witnesses & forensic consultants.   (Site not responding. Last check: 2007-10-21) Hydrology (from Greek: Yδρoλoγια, Yδωρ+Λoγos, Hydrologia, the "study of water") is the study of the movement, distribution, and quality of water throughout the Earth, and thus addresses both the hydrologic cycle and water resources. A practitioner of hydrology is a hydrologist, working within the fields of either earth or environmental science, or civil and environmental engineering. Available to be hydrology expert witnesses and provide hydrology forensic consulting in hydrology litigation, in addition prepare hydrology expert witness reports for use in deposition and/or in-court trial testimony. www.expertwitness.com /clst/220/hydrology-experts.htm   (350 words)

MODRET - infiltration from stormwater retention ponds using MODFLOW - runoff hydrographs   (Site not responding. Last check: 2007-10-21) The Infiltration module of the program uses a modified Green and Ampt infiltration equation to calculate unsaturated infiltration and a modified USGS model "A Modular Three-Dimensional Finite-Difference Ground-Water Flow Model," McDonald and Harbaugh, 1984, to calculate saturated infiltration. It is assumed the user is a professional with a background in hydrology and/or hydrogeology and has a good command in surface runoff and groundwater flow modeling. After calculation of infiltration losses, the runoff hydrograph can be routed through infiltration and a new "Runoff-Infiltration" hydrograph can be generated which can then be reused in other surface runoff routing models. www.scisoftware.com /products/modret_details/modret_details.html   (1200 words)

Rain Garden Network | Glossary The primary function of buffers is to protect the receiving water from sediment and pollutants derived from upstream areas. In hydrology, the entire area that is flooded at a recurrence interval of 100 years. Infiltration: The downward movement of water from the surface of the land to subsoil. www.raingardennetwork.com /glossary.htm   (1188 words)

[No title] Hydrology and Water Resourcss in Arizona and the Southwest 13: 27-34. Infiltration rates and erosion associated with reclaimed coal mine spoils in west central New Mexico. Effects of brush to grass conversion on the hydrology and erosion of a semiarid southwestern rangeland watarshed. www.rmrs.nau.edu /publications/madrean/bibfiles/Hydro.txt   (13606 words)

Yucca Mountain Project Infiltration studies at Yucca Mountain quantify the movement and distribution of precipitation from the surface and recharge to the ground-water system. The infiltration rate and distribution control, in part, the movement of water down to the proposed repository level, and potentially, radionuclides from the repository to the underlying water table. Five unsaturated-zone boreholes were instrumented with sensors that provided data on the distribution and fluctuations of pressure, temperature, and water vapor associated with natural and human-induced phenomena. water.usgs.gov /ympb/unsaturatedzonehydrology.htm   (324 words)

Hydrology Programs - The School of Natural Resources and Environment at the University of Florida Because water consumption has steadily risen in Florida, the study of hydrology is crucial for ourwater and related environmental impacts is critical for optimal water management. Construction activity compacts soils such that areas that are not paved or built on have lower infiltration rates, which leads to more runoff and decreases the amount of groundwater recharge. Last year (see 2002-2003 SNRE-sponsored hydrology projects), Graetz and his graduate student, Travis Henselman, successfully developed a novel sample preparation method involving the extraction of estrogens from environmental matrices (manure, soil, and water) using a combination of liquid and solid phase extraction with Carbograph and C18 adsorbents. snre.ufl.edu /programs/hydrology.htm   (2213 words)

DuluthStreams - urban hydrology Hydrology is the study of water's properties, distribution and circulation on Earth. At 30 to 50% impervious (such as in high-density residential developments), runoff is tripled, and at 75 to 100% impervious (as is common in commercial areas), the majority of rainfall becomes runoff, and infiltration is less than 1/3 of what it was prior to development. Second, due to the reduced infiltration volumes, there is less water available to be released slowly into the stream over time, resulting in lower water levels between rainfall events. www.duluthstreams.org /understanding/stormwater_hydrology.html   (756 words)

Hydrology and Remote Sensing Laboratory : People & Places ARS representative to the U.S. Water Resources Council, Hydrology Committee which set flood frequency estimation standards for the U.S. ARS representative on the Hydrology Subcommittee and Interagency Committee on Water Data. Use of axisymmetric infiltration model and field data to determine hydraulic properties of soils. Rawls, W. J., Giménez, D. and Grossman, R. Use of soil texture, bulk density, and the slope of the water retention curve to predict saturated hydraulic conductivity. www.ars.usda.gov /pandp/people/people.htm?personid=10070   (727 words)

661 module 00 Infiltrated water is therefore forced to flow laterally towards the pavement edges. Horton actually recommended infiltration as a function of rain depth, but current practice of using double-ring infiltrometers to calibrate the Horton equation does not allow infiltration measurements to be made as a function of rain depth, only as a function of time for the ponded test conditions. The lowest infiltration rates were observed in areas having heavy foot traffic and in areas obviously impacted by silt, while the highest rates were in relatively undisturbed areas. www.eos.uoguelph.ca /webfiles/wjames/homepage/Teaching/661/wj661M12W00.html   (16319 words)

Forest Watershed Hydrology   (Site not responding. Last check: 2007-10-21) Forests affect the hydrology of watersheds in various and complex ways, by increasing evapotranspiration, increasing soil infiltration, intercepting cloud moisture, reducing the nutrient load of runoff, and more. Infiltration may also be improved by increased earthworm activity and the development of root channels as trees grow. Plow pans significantly reduce infiltration and increase surface runoff, thereby increasing the potential for erosion and nutrient loss. www.ctahr.hawaii.edu /forestry/Data/hydrology.asp   (1290 words)

Analysis of Stormwater Infiltration Ponds on the North Carolina Outer Banks Stormwater infiltration pond systems are approved by the State as an option for retaining storm water on the developed site; however, the long-term performance of these systems has not been measured or determined. DMPOND was composed of three components: a seepage component using the approximate method for calculating three dimensional pond seepage, a hydrologic component for calculating stormwater runoff and water table elevation in the pond watershed, and a reservoir component for predicting pond stage, storage, and overflow. This recommendation is based on the hydrology of the pond system; however, the effects of infiltration ponds on the water quality of the groundwater has not been considered and should be the topic of future research. www2.ncsu.edu /ncsu/wrri/reports/report254.html   (1546 words)

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