Dimensionless straight-type llnes for aquifer tests

Şen Z.

Journal of Hydraulic Engineering, vol.116, no.9, pp.1145-1156, 1990 (Scopus) identifier


Nonlinear flow-type straight-line expressions are derived on the basis of exponential flow law instead of the linear Darcy law. A procedure of hypothesis testing for the flow-regime linearity is explained step-by-step. It is concluded that any straight line for late time-drawdown data on semilogarithmic paper does not necessarily guarantee the accurate application of the classical Jacob methods but confirms that the flow is radial. A dimensionless time-drawdown plot is proposed for the identification of flow regime. If the dimensionless time-drawdown plot for the late time-drawdown data fits a straight line with the same slope as the Jacob straight line, then the underlying flow regime is linear. Otherwise the flow regime is nonlinear. Once the flow regime is nonlinear, the necessary equations are given for the estimation of parameters such as the storability, turbulence exponent, and transmissivity. Finally, the application of the methodology has been performed for some field data available in the literature. © ASCE.