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Drawdowns in Large‐Diameter Wells Due to Decreasing Abstraction Rates
Author(s) -
Rushton K. R.,
Singh V. S.
Publication year - 1983
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1983.tb01938.x
Subject(s) - drawdown (hydrology) , aquifer , abstraction , constant (computer programming) , water well , petroleum engineering , mechanics , geology , geotechnical engineering , computer science , groundwater , physics , philosophy , epistemology , programming language
Due to characteristics of centrifugal pumps, most pumping tests in large‐diameter wells exhibit a decreasing abstraction rate with increasing drawdown. Type curves are obtained for the case of abstraction rates which are functions of the well drawdown; values for the type curves are obtained from a numerical model. For the case of constant abstraction, these curves provide an alternative to the classical approach. By plotting the ratio of drawdowns at different times, it is possible to identify more easily when the aquifer begins to contribute to the well discharge. The practical application of the technique is illustrated by a field example.