J. Radyk
R. L. Michel
J. A. Izbicki
2000
<div id="abstracts" class="Abstracts"><div id="aep-abstract-id14" class="abstract author"><div id="aep-abstract-sec-id15"><p><span>Previous studies indicated that small amounts of recharge occur as <a title="Learn more about Infiltration" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/infiltration" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/infiltration">infiltration</a> of intermittent <a title="Learn more about Streamflow" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/streamflow" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/streamflow">streamflow</a> in washes in the upper Mojave River <a title="Learn more about Basins" href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/basins" data-mce-href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/basins">basin</a>, in the western Mojave <a title="Learn more about Deserts" href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/deserts" data-mce-href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/deserts">Desert</a>, near Victorville, California. These washes flow only a few days each year after large <a title="Learn more about Storms" href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/storms" data-mce-href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/storms">storms</a>. To reach the <a title="Learn more about Water Table" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/water-table" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/water-table">water table</a>, water must pass through an unsaturated zone that is more than 130</span> <span>m thick. Results of this study, done in 1994–1998, show that infiltration to depths below the root zone did not occur at control sites away from the wash. At these sites, volumetric water contents were as low as 0.01 and water potentials (measured as the combination of <a title="Learn more about Solutes" href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/solutes" data-mce-href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/solutes">solute</a> and <a title="Learn more about Matric Potential" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/matric-potential" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/matric-potential">matric potentials</a> using a water activity meter) were as negative as −14,000</span> kPa. Water-vapor movement was controlled by highly negative solute potentials associated with the accumulation of soluble salts in the unsaturated zone. Highly negative matric potentials above and below the zone of maximum solute accumulation result from movement of water vapor toward the highly negative solute potentials at that depth. The<span> </span><i>δ</i><sup>18</sup>O and<span> </span><i>δ</i><span>D (delta <a title="Learn more about Oxygen 18" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/oxygen-18" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/oxygen-18">oxygen-18</a> and delta deuterium) <a title="Learn more about Isotopic Composition" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/isotopic-composition" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/isotopic-composition">isotopic composition</a> of water in coarse-grained deposits plots along a Rayleigh <a title="Learn more about Distillation" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/distillation" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/distillation">distillation</a> line consistent with removal of water in coarse-grained layers by vapor transport. Beneath Oro Grande Wash, water moved to depths below the root zone and, presumably, to the water table about 130</span> m below land surface. Underneath Oro Grande Wash, volumetric water contents were as high as 0.27 and water potentials (measured as matric potential using tensiometers) were between −1.8 and −50 <span>kPa. On the basis of <a title="Learn more about Tritium" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/tritium" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/tritium">tritium</a> data, water requires at least 180–260 years to infiltrate to the water table. Clay layers impede the downward movement of water. Seasonal changes in water vapor composition underneath the wash are consistent with the rapid infiltration of a small quantity of water to great depths and subsequent equilibration of vapor with water in the surrounding material. It may be possible to supplement natural recharge from the wash with imported water. Recharge to the wash may be advantageous because the unsaturated zone is not as dry as most areas in the desert and concentrations of soluble salts are generally lower underneath the wash.</span></p></div></div></div>
application/pdf
10.1016/S0022-1694(00)00331-0
en
Elsevier
Water movement through a thick unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California, USA
article