Transmissivity and diffusivity variation in the anisotropic aquifers

摘要

The hydraulic properties of aquifers described in this paper are physical dimensions determined as a rule by pumping tests. The extraction of a constant output of water from an aquifer studied by single wat-er well determines the formation of a cone of depression around the well axis. The size and the form of this cone of depression are depending on pumping duration and the structure of the tested aquifer. The developm- ent cone of depression during pumping test was studied for two types of motions of the drawdown: 1) unifor- mly decreasing motion; 2) non-uniformly decreasing motion. As a result of this analytical proof have resulted new formulas for the calculation of the hydraulic transmissivity (T), radius of influence (R) and hydraulic diffusivity (a). These hydraulic properties of the aquifers are determinate for each successive increase of the drawdown and time measured during pumping test.