Title	Estimation of hydraulic properties in permafrost-affected soils using a two- directional freeze-thaw algorithm
Author	Bolton, W.R.; Boike, J.; Overduin, P.P.
Author Affil	Bolton, W.R., Alfred Wegener Institute for Polar and Marine Research, Federal Republic of Germany
Source	International Conference on Permafrost (ICOP) Proceedings, Vol.9, p.155-158, ; Ninth international conference on Permafrost, Fairbanks, AK, June 29-July 3, 2008, edited by D.L. Kane and K.M. Hinkel. Publisher: [publisher varies], [location varies], International
Publication Date	2008
Notes	In English. 17 refs. GeoRef Acc. No: 285534
Index Terms	active layer; freezing; freeze thaw cycles; hydraulics; hydrodynamics; hydrology; analysis (mathematics); permafrost; permafrost hydrology; physical properties; porosity; soils; thawing; United States-- Alaska; Alaska; algorithms; frost action; Imnavait Creek basin; mathematical methods; TDFT; two-directional freeze-thaw; United States
Abstract	In this study, a two-directional freeze-thaw (TDFT) algorithm is used to estimate the hydraulic conductivity and storage capacity of permafrost-affected soils. The physically based TDFT algorithm is based upon the Stefan equation. The algorithm is driven by both the surface temperature and temperature at a specified depth and uses physical properties of the soil (bulk density, porosity, soil moisture, organic and mineral fraction, and freezing temperature of water) as input variables. The TDFT is tested in a wet valley bottom and along a relatively dry hill slope in the Imnavait Creek Watershed, Alaska. Results indicate that the timing of thaw/freezeback periods, the maximum thaw depth, and latent heat effects are accurately simulated. Using the TDFT algorithm to derive hydraulic variables is an improvement from the previous methods used to represent the active layer in hydrological modeling studies.
URL	http://www.blue-europa.org/nicop_proceedings/1%20Vol%201%20(i-250).pdf
Publication Type	conference paper or compendium article
Record ID	62005838