Abstract

HERNANDEZ-VALDES, Armando O.. Relation between Specific Capacity and Transmissivity with Non-linear Flow and Partial Penetration Well. Tecnol. cienc. agua [online]. 2014, vol.5, n.4, pp.103-117. ISSN 2007-2422.

Specific capacity has been used by several authors, including the author of the present work, to estimate the Darcian transmissivity of an aquifer, given the lack of data related to these systems because of the costs involved in conducting pumping tests to determine transmissivity. Several factors can cause significant errors in this estimate. This work presents the analytical expressions and results from pumping tests in order to demonstrate the error magnitudes, especially when non-linear fluid is present around pumping wells, in the case of a partial penetration well, or there are recharge effects or caves that quickly stabilize the levels of the wells during pumping. In the first two cases the Darcian transmissivity of the aquifer is underestimated, whereas in the latter it is overestimated. Results from a pumping test using two satellites, or observation wells are also shown. Although this is an uncommon situation, interpretation is possible based on one of the proposals above to calculate hydrogeological properties under a non-linear flow regime. Errors in determining the storage coefficient and the use of an inadequate specific capacity parameter to estimate transmissivity were found.

Keywords : Non linear regime; partial penetration; specific capacity-transmissivity; well hydraulics.