Coupling flow and transport for groundwater parameter and unknown condition identification using adjoint state method
Date Issued
2009
Date
2009
Author(s)
Liu, Hung-Jen
Abstract
In this paper, groundwater simulation models, adjoint state method, gradient search method, and least square algorithm are combined to formulate an efficient optimization approach to solve the groundwater inverse problem. The adjoint state method is used to evaluate effectively the gradient of objective function with respect to parameter or condition.he horizontal two-dimensional confined aquifer is the research target. First, the parameter identification is discussed through a designed tracer test. Head, flux, zeroth and first moment observations are utilized to estimate hydraulic conductivity(K) field. The moment observations at different locations contain some indirect trend information of K field. Next to head observations, they provide additional knowledge useful to parameter identification in groundwater system. Using all three kinds together, the case study demonstrates to elevate the efficiency and accuracy of solution substantially.econd, the complete inverse problem is taken into consideration. A designed pumping test is performed to simultaneously estimate aquifer parameters, initial condition, and boundary conditions in groundwater modeling. The correlation analysis shows high connection between storage coefficient and initial condition. Besides, transmissivity and boundary conditions are also highly correlated. A time series of unsteady head is needed for storage coefficient and initial condition estimation. The observation near boundary is very effective on boundary condition estimation. The observation at pumping well mostly contributes to the estimation of transmissivity.
Subjects
groundwater modeling
flow and transport
parameter identification
complete inverse problem
adjoint state method
experimental design
contribution of observation
data assimilation
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-F91521308-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):e6ed99e2206e0d661cb8bf5b123a89e0