TY - JOUR
T1 - Analysis of pumping test data for determining unconfined-aquifer parameters
T2 - Composite analysis or not?
AU - Yeh, Hund-Der
AU - Huang, Yen Chen
PY - 2009
Y1 - 2009
N2 - Recently, composite analysis (CA), which simultaneously analyzes all drawdown data from multiple observation wells, has been applied to determine the hydraulic parameters of an unconfined aquifer. Moench (1994) claimed that the value of specific yield (Sy) determined from non-composite analysis (nonCA) is sometimes unrealistically low as compared with that obtained by water-balance calculation, and results from CA are better representative of aquifer properties than those from nonCA. To examine the validity of this assertion, the drawdown data from a pumping test conducted at Cape Cod, Massachusetts, USA, were analyzed using both nonCA and CA methods. The results show that the mean estimates of hydraulic conductivity and Sy determined from CA are close to those determined from nonCA. In some cases the analysis based on CA also results in low estimates of Sy as compared with those determined based on non CA. A hypothetical case study is presented, which examines the effect of measurement errors on the estimated parameters. The results indicate that the CA method also gives poorer estimates of Sy than the nonCA method if the pumping test data contain measurement errors. Moench AF (1994) Specific yield as determined by type-curve analysis of aquifer-test data. Ground Water, 32(6):949-957.
AB - Recently, composite analysis (CA), which simultaneously analyzes all drawdown data from multiple observation wells, has been applied to determine the hydraulic parameters of an unconfined aquifer. Moench (1994) claimed that the value of specific yield (Sy) determined from non-composite analysis (nonCA) is sometimes unrealistically low as compared with that obtained by water-balance calculation, and results from CA are better representative of aquifer properties than those from nonCA. To examine the validity of this assertion, the drawdown data from a pumping test conducted at Cape Cod, Massachusetts, USA, were analyzed using both nonCA and CA methods. The results show that the mean estimates of hydraulic conductivity and Sy determined from CA are close to those determined from nonCA. In some cases the analysis based on CA also results in low estimates of Sy as compared with those determined based on non CA. A hypothetical case study is presented, which examines the effect of measurement errors on the estimated parameters. The results indicate that the CA method also gives poorer estimates of Sy than the nonCA method if the pumping test data contain measurement errors. Moench AF (1994) Specific yield as determined by type-curve analysis of aquifer-test data. Ground Water, 32(6):949-957.
KW - Compositeanalysis
KW - Groundwater hydraulics
KW - Hydraulic testing
KW - USA
KW - Unconfined aquifer
UR - http://www.scopus.com/inward/record.url?scp=67649391024&partnerID=8YFLogxK
U2 - 10.1007/s10040-008-0413-z
DO - 10.1007/s10040-008-0413-z
M3 - Article
AN - SCOPUS:67649391024
SN - 1431-2174
VL - 17
SP - 1133
EP - 1147
JO - Hydrogeology Journal
JF - Hydrogeology Journal
IS - 5
ER -