نتایج جستجو برای: phreatic water

تعداد نتایج: 550913  

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...

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...

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...

2014
Ruiliang Jia Jinlong Zhou Yexin Gao Vincenzo Torretta

A VDEAL (V is the lithology of the vadose zone, D is the groundwater depth, E is the degree of groundwater exploitation, A is the aquifer characteristics and L is the land use pattern.) model, which is suitable for a vulnerability evaluation of the groundwater in arid inland areas, and that is based on the GOD (G is the groundwater status, O is overburden feature and D is groundwater depth) met...

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...

Journal: :Isotopes in environmental and health studies 2013
Silvina C Carretero Cristina Dapeña Eduardo E Kruse

This contribution presents the hydrochemical and isotopic characterisation of the phreatic aquifer located in the Partido de la Costa, province of Buenos Aires, Argentina. In the sand-dune barrier geomorphological environment, groundwater is mainly a low-salinity Ca-HCO3 and Na-HCO3-type, being in general suitable for drinking, whereas in the continental plain (silty clay sediments), groundwate...

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...

2015
J. F. Costelloe V. Matic

Understanding the water balance of large groundwater systems is fundamental for the sustainable management of the resource. The vertical leakage (i.e. discharge to upper aquifers or the unconfined water table) component of the Great Artesian Basin (GAB) is an example of a poorly constrained but large component of the water balance of Australia’s largest groundwater resource. Field estimates of ...

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...

2010
M. Musgrove

0022-1694/$ see front matter Published by Elsevier doi:10.1016/j.jhydrol.2010.04.036 * Corresponding author at: US Geological Survey, 1505 Ferguson Lane, Austin, TX 78754, United States. E-mail address: [email protected] (M. Musgrov A two and a half year study of two adjacent watersheds at the Honey Creek State Natural Area (HCSNA) in central Texas was undertaken to evaluate spatial and tempora...

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