Truncation effect on estimation of transport parameters for slug-injection tracer tests

For slug-injection tracer tests, concentrations below the detection limit of measurement instrument can cause truncation observed data. This study investigated effect on estimation error parameters based analytical solutions and results laboratory-scale experiments. Spatial moment analysis was performed to estimate measured total mass transport parameters, including pore velocity longitudinal transverse dispersivities. Increasing travel distance caused dispersivities be underestimated regardless dimensionality because hydrodynamic dispersion occurs with increasing distance, which smoothens concentration front. The one- two-dimensional cases showed that dispersivity depended dimensionality. In contrast, no such dependence; center did not change as unmeasured portion due increased plume, exhibited a Gaussian distribution, truncated symmetrically. experiment, likewise limit, but there were large differences in at dimensionless parameter reached value zero between experimental solution. is initial plume experiment finite size. Thus, design factors scale, device, should considered minimize excluding velocity.