P. Jussel et al., TRANSPORT MODELING IN HETEROGENEOUS AQUIFERS .2. 3-DIMENSIONAL TRANSPORT MODEL AND STOCHASTIC NUMERICAL TRACER EXPERIMENTS, Water resources research, 30(6), 1994, pp. 1819-1831
Statistical information on the coherent sedimentary structures of high
ly heterogeneous gravel deposits (Jussel et al., this issue) is used t
o investigate numerically the transport of conservative tracers. The d
ata are the basis for a numerical generation of synthetic aquifer mode
ls, whose statistical distributions of the sedimentary structures and
their hydraulic conductivity and porosity correspond to the findings i
n the investigated deposits. A three-dimensional finite element flow m
odel and a corresponding random-walk transport model were developed fo
r this purpose. Because of the large number of finite elements needed,
the solution algorithm is optimized for applications on vector-type c
omputers. In order to minimize the discretization errors a special int
erpolation technique is applied to the determination of the local velo
city vector. Ten stochastic, numerical transport experiments over a tr
ansport distance of 100 m were carried out with synthetic gravel aquif
er models. They allow the mean tracer velocity, the effective hydrauli
c conductivity, and the dispersion parameters to be estimated. These e
stimates are compared with estimates of these parameters from current
theories for the flow and the tracer transport in random, correlated,
anisotropic hydraulic conductivity fields.