A new approach for estimating transmissibility from specific capacity.

Autor: Hurr, R. Theodore
Zdroj: Water Resources Research; 1966, Vol. 2 Issue 4, p657-664, 8p
Abstrakt: Transmissibility estimated from specific capacity is subject to error, because the effects of duration of pumping and specific yield are not evaluated. Rearrangement of the Theis equation provides a mathematical relation for evaluating drawdown during nonequilibrium conditions and delayed yield from storage at any time after pumping begins. This relation is obtained from type curves of u plotted against u[ W( u)] where u[ W( u)] is equal to 1.632 × 10−2 [( S y) r2 s/ Qt]. The only term that needs to be assumed is specific yield. The error of the estimated transmissibility will be 30 to 40% of the error made in assuming the apparent specific yield for u = 10−2 and 10 to 15% for u less than 10−4. The curves presented in the paper were used to construct a transmissibility map of the valley-fill aquifer in the Arkansas River valley of Colorado. The map was the foundation for an analog-model analysis of the aquifer system. The transmissibilities estimated from the type curves correlate well with transmissibilities determined from aquifer tests and estimated from test-hole logs. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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