Mobile-Immobile Water Solute Transport Model in Unsatchem:
Field Application. (S02-vaughan971694-poster)
Authors:
P.J. Vaughan* - USDA-ARS Salinity Lab.
D.L. Suarez - USDA-ARS Salinity Lab.
Abstract:
The mobile-immobile water (MIM) solute transport model was programmed into the Unsatchem multicomponent solute transport code as a new option. Inclusion of this model extends the code to permit MIM treatment of preferential flow effects on solute transport. The model was tested using a data set for 45 locations in an agricultural field in the San Joaquin Valley. The principal data were chemical analyses of 1:1 extracts for samples taken from six depths (0-1.8 m) in five sampling periods between November, 1995 and November, 1997. These chemical analyses indicated that chloride concentration profiles had the following statistics: 50% increased with depth, 30% had maxima and 20% had other shapes. Modeling of vertical transport by the uniform flow option in Unsatchem for November, 1995 through November, 1997 resulted in a greater reduction of chloride concentrations in the soil profile than actually occurred. Also the uniform flow option produced chloride profiles that consistently increased with depth. By increasing potential transpiration and utilizing the MIM option, the model provided substantially improved predictions of the chloride concentrations. This model also showed improved capability to correctly predict maxima in the profiles.
Speaker Information: Peter Vaughan, USDA-ARS Salinity Lab., George E. Brown Jr. Salinity Lab.450 W Big Sprin, Riverside, CA 92507; Phone: 909-369-4875; E-mail: [email protected]
Session Information: Monday, November 3, 2003, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 1224) Keywords: Mobile-Immobile; multicomponent; transport; field application
