HR: 1340h
AN: H13B-1244    [Abstracts]
TI: A Study for Residual Drawdown Solution with Considering the Wellbore Storage
AU: * Wang, C
EM: ctwang.ev90g@nctu.edu.tw
AF: Institute of Environmental Engineering, National Chiao Tung University, No. 75, Po-Ai Street, Hsinchu, 300, Taiwan
AU: Yeh, H
EM: hdyeh@mail.nctu.edu.tw
AF: Institute of Environmental Engineering, National Chiao Tung University, No. 75, Po-Ai Street, Hsinchu, 300, Taiwan
AB: A recovery test is to measure the residual drawdown, which is the well water level after the shutdown of pumping test, and analyze the residual drawdown data for the estimation of the aquifer parameters such as transmissivity and storativity. In the past, the methodology of the recovery data analysis is based on the Theis equation associated with superposition principle and thus neglects the effect of wellbore storage even the test well has a finite-diameter. In this paper, we develop a new residual drawdown solution for describing the recovery water level in the pumping well with considering the wellbore storage. The solution shows that the decrease of the residual drawdown depends on the boundary condition related to the well drawdown and the initial condition related to the aquifer drawdown. In addition, the well residual drawdown can be approximated by Theis equation associated with superposition principle with a good result when recovery time is large.
DE: 1829 Groundwater hydrology
DE: 1899 General or miscellaneous
SC: Hydrology [H]
MN: 2007 Fall Meeting