نتایج جستجو برای: phreatic line

تعداد نتایج: 411968  

Behrooz Dahanzadeh Farrokh Falahat Hossein Fathian,

One of the problems of existing irrigation networks is seepage phenomena. Seepage problem and its control in irrigation channels is one of the most important issues in the design, construction, maintenance and operation of these channels. In this study, simulated the rate of seepage and phreatic lines in the Mianab irrigation and drainage channels located in the Karun basin using mathematical t...

2010
Wolfgang Dreybrodt Georg Kaufmann

When water from the surface, e.g. from a lake, fl ows down through porous carbonate rocks, through a region with high hydraulic conductivity and encounters the water table of a phreatic aquifer, both waters mix by diffusion along their boundary. In a carbonate aquifer, where both surface and phreatic waters are saturated with respect to calcite, mixing corrosion causes renewed dissolution capac...

Journal: :Computers & Geosciences 2012
Yu-xin Jie Yan-feng Wen Gang Deng Rui Chen Xu Ze-ping

Generally seepage analysis and stress–strain analysis are conducted separately in the analysis of dams with varied water levels, which neglects the impact of soil deformation on seepage. The impact, however, is significant when the water level varies greatly. In this study, a simplified approach for consolidation analysis of unsaturated soil is used to conduct numerical simulations of water-fil...

2007
D.-S. Jeng

Tidal fluctuations in a leaky confined coastal aquifer are damped significantly due to leakage into an overlying phreatic aquifer. Jiao and Tang [1999] presented an analytical solution to a simple model describing this phenomenon. Their solution assumes that the tidal fluctuations in the overlying phreatic aquifer are negligible (i.e., a static phreatic aquifer). Here we examine dynamic effects...

2003
Michael B. Jenkins

Rhizobial symbionts were isolated from the surface (0–0.5 M) and phreatic (3.9–5.0 M) root environments of a mature mesquite woodland in the Sonoran Desert of Southern California, and from variable depths (0–12 m) of non-phreatic mesquite ecosystems in the Chihuahuan Desert of New Mexico. They were tested for their ability to tolerate high salinity, and respire NO3 2 as mechanisms of free-livin...

Journal: :Int. J. Math. Mathematical Sciences 2012
Adrian Carabineanu

We present an inverse method for the study of the seepage from soil channels without lining. We give integral representations of the complex potential, velocity field, stream lines, free phreatic lines, and contour of the channel by means of Levi-Civitá’s function ω. For different values of the Taylor coefficients of ω, we calculate numerically the contour of the channel, the phreatic lines, th...

Journal: :E3S web of conferences 2021

The article presents the results of field studies to determine unsteady filtration in Tupolang dam core. Calculations are carried out for phreatic line curve core under various velocities reservoir draw-off and water yield coefficient. At same time it has been established that increase velocity leads pressure, decrease factor pressure. turn, contributes intensity

2018
Hideki Ueda Masashi Nagai Toshikazu Tanada

On Ioto Island (Iwo-jima), 44 phreatic eruptions have been recorded since 1889, when people began to settle there. Four of these eruptions, after the beginning of continuous observation by seismometers in 1976, were accompanied by intense seismic activity and rapid crustal deformation beforehand. Other eruptions on Ioto were without obvious crustal activities. In this paper, we discuss the mech...

Journal: :International Journal for Numerical Methods in Engineering 2022

The large-deformation mechanics and multiphysics of continuous or fracturing partially saturated porous media under static dynamic loads are significant in engineering science. This article is devoted to a computational coupled periporomechanics paradigm assuming passive air pressure for modeling failure variably media. governing equations bulk fracture material points formulated the current/de...

2004
MARYLYNN MUSGROVE JAY L. BANNER

A 4-yr study of spatial and temporal variability in the geochemistry of vadose groundwaters from caves within the Edwards aquifer region of central Texas offers new insights into controls on vadose groundwater evolution, the relationship between vadose and phreatic groundwaters, and the fundamental influence of soil composition on groundwater geochemistry. Variations in Sr isotopes and trace el...

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