MULTI-REGION REACTIVE TRANSPORT DUE TO STRONG ANISOTROPY IN UNSATURATED SOILS WITH EVOLVING SCALES OF HETEROGENEITY

Ward, Andy

Pacific Northwest National Laboratory (U.S.)

关键词: Solutes;    Forecasting;    Sediments;    Anisotropy;    Waste Management;   

DOI  :  10.2172/893181
RP-ID  :  EMSP-86952-2005
RP-ID  :  FG07-02ER63512
RP-ID  :  893181

美国|英语

来源: UNT Digital Library

【 摘 要 】

At Hanford, the prediction of field-scale flow and transport in the vadose zone beneath tank farms and other waste-management facilities provide as good example of the limitations of current conceptualizations. Contaminant plumes in Hanford's vadose zone typically show extensive lateral spreading with splitting along flow paths and multiple zones of high-contaminant concentrations, even in sediments that appear homogeneous and isotropic at the regional scale. Because of the limited success in predicting current contaminant distributions using existing conceptual models and approaches to parameterization, there is some uncertainty about predictions of future transport behavior. This is mostly because current parameter upscaling procedures result in overly smoothed descriptions of the hydraulic functions that cause many of the important details (e.g. extreme water and solute flux, anisotropy), known to be caused by finescale heterogeneity, to be ignored.