EPA On-line Tools for Site Assessment Calculation
Dispersivity also acts transverse and vertically to the plume axis. Generally dispersivity in these directions is lower. Gelhar noted that the data on transverse and vertical dispersivity was much sparser than longitudinal and most of it of low reliability. A comment in the paper is sometimes used as a guide: that transverse dispersivity was an order-of-magnitude lower than the longitudinal and the vertical an order of magnitude lower than the transverse.