HR: 1340h
AN: H23G-1689    [Abstracts]
TI: Development of Pneumatic Inverse Model for Estimating Permeability and Porosity of Unsaturated Soils
AU: * Ni, C
EM: nichuenf@gmail.com
AF: Institute of Applied Geology, National Central University, Jhongli, 32001, Taiwan
AU: Yeh, T
EM: ybiem@mac.hwr.arizona.edu
AF: Department of Hydrology and Water Resources, The University of Arizona, Tucson, AZ 85721, United States
AU: Teng, Y
EM: rf5523@yahoo.com.tw
AF: Institute of Applied Geology, National Central University, Jhongli, 32001, Taiwan
AB: The distributions of permeability and porosity are key factors that control airflow and gas phase transport in unsaturated soils. This study develops a pneumatic inverse model to estimate the distributions of permeability (K) and porosity (n) in unsaturated soils. Based on the concept of tomography surveys, the developed model accounts for compressibility and density of air and estimates the hydrgeologic parameters using air pressure measurements from sequential cross-hole pneumatic pumping or injection tests. Two synthetic examples and a laboratory sand column test were used to validate and test our inverse model in estimating the distributions of permeability and porosity. Results of the comparison show that our pneumatic inverse model can exactly reconstruct the property (i.e., permeability and porosity) fields if the well-defined conditions are met. With relatively small number of available measurements, the proposed model can closely capture the patterns and the magnitude of estimated properties in unsaturated soils. The validation with one-dimensional column test showed that the proposed inverse model can clearly map the patterns of different soils in the sand column. However, the estimated values of permeability and porosity show slightly difference from the values measured from the laboratory test.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1847 Modeling
DE: 1869 Stochastic hydrology
SC: Hydrology [H]
MN: 2007 Fall Meeting