Monday, November 13, 2006

Automated Method for Measuring Unsaturated Hydraulic Conductivity and Water Retention Under Steady State Conditions.

Marcel Schaap, Shantz, University of Arizona, Soil Water and Env Science, Tucson, AZ 85721 and Peter Shouse, USDA-ARS U.S. Salinity Lab., 450 W Big Springs Rd., Riverside, CA 92507-4617.

<meta content=" 2.0 (Linux)" name="GENERATOR" /><meta content="Marcel Schaap" name="AUTHOR" /><meta content="20060511;17101200" name="CREATED" /><meta content="16010101;0" name="CHANGED" /> <style> <p>We present a new method for measuring unsaturated hydraulic conductivity and water retention under steady state conditions. The method consists of a flux-head method in which the flux is regulated with a pressure gradient inside a soil sample. The head is regulated with a precision pressure controlled burette with a resolution of 0.1 cm. At steady state (unit gradient flow) the flow through the sample is directly related to the unsaturated hydraulic conductivity. At the same time the water level in the pressure controlled burette provides information about inflow or outflow into the sample, and therefore, water retention. The system is fully automated and computer controlled and allows the measurement of unsaturated hydraulic conductivity between 1000 cm/day to less than 1 cm/day. Water retention can be measured with a precision of approximately1%. The system is very flexible and can be used for several other applications. </div> <br> <p><div class="paperlinks"> Back to <a href="S2737.HTM">Soil Hydraulic Properties: I</a><br> Back to <a href="D1085.HTM">S01 Soil Physics</a><br><br>Back to <a href='index.html'>The ASA-CSSA-SSSA International Annual Meetings (November 12-16, 2006)</a><br></div> </div> </div><!-- end "papercontent" --> </body></html>