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The Scientific World Journal
Volume 2013 (2013), Article ID 240280, 10 pages
http://dx.doi.org/10.1155/2013/240280
Research Article

Dynamics of Soil Water Evaporation during Soil Drying: Laboratory Experiment and Numerical Analysis

School of Earth Sciences and Engineering, Hohai University, Nanjing 210098, China

Received 4 November 2013; Accepted 8 December 2013

Academic Editors: J. Liu, I. Zbicinski, and Z. Zhang

Copyright © 2013 Jiangbo Han and Zhifang Zhou. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Laboratory and numerical experiments were conducted to investigate the evolution of soil water evaporation during a continuous drying event. Simulated soil water contents and temperatures by the calibrated model well reproduced measured values at different depths. Results show that the evaporative drying process could be divided into three stages, beginning with a relatively high evaporation rate during stage 1, followed by a lower rate during transient stage and stage 2, and finally maintaining a very low and constant rate during stage 3. The condensation zone was located immediately below the evaporation zone in the profile. Both peaks of evaporation and condensation rate increased rapidly during stage 1 and transition stage, decreased during stage 2, and maintained constant during stage 3. The width of evaporation zone kept a continuous increase during stages 1 and 2 and maintained a nearly constant value of 0.68 cm during stage 3. When the evaporation zone totally moved into the subsurface, a dry surface layer (DSL) formed above the evaporation zone at the end of stage 2. The width of DSL also presented a continuous increase during stage 2 and kept a constant value of 0.71 cm during stage 3.