Use of Computer Programs STLK1 and STWT1 for Analysis of Stream-Aquifer Hydraulic Interaction. A Product of the Ground Water Resources Program

摘要

This report describes the use of two computer programs, STLK1 and STWT1 to analyze the hydraulic interaction of streams with confined, leaky, and water-table aquifers during periods of stream-stage fluctuations and uniform, areal recharge. Analysis of idealized, hypothetical stream-aquifer systems is used to show how aquifer type, aquifer boundaries, and aquifer and streambank hydraulic properties affect aquifer response to stresses. Published data from alluvial and stratified-drift aquifers in Kentucky, Massachusetts, and Iowa are used to demonstrate application of the programs to field settings. Stream-stage fluctuations and recharge are applied to the systems as hydraulic stresses. The models are calibrated by matching ground-water levels calculated with computer program STLK1 or STWT1 to measured ground-water levels. The analytical models are used to estimate hydraulic properties of the aquifer, aquitard, and streambank; to evaluate hydrologic conditions in the aquifer; and to estimate seepage rates and bank-storage volumes resulting from flood waves and recharge.