Master of Science
Roger W. Meier
Cost- and time-effective injection methods using mini-piezometers are widely used in hyporheic research for estimating hydraulic conductivity (K). To check the performance of a range of mini-piezometer screens with drilled holes, we simulated constant-head injection tests in a uniform, isotropic streambed, using a specially designed laboratory apparatus. Applying accepted methods by Hvorslev and Cardenas & Zlotnik, with subsequent modifications, we studied the effects of screen length, hole diameter, and hole spacing on the shape factor (F), and thus on the estimated K. We also investigated the nature of the injected flow by studying the spatial distribution of piezometric head within the porous medium. When the proportion of screen openings is above 6%, both methods predict K adequately, while the shape factor proposed by Bouwer & Rice underestimates consistently. A proposed empirical equation for F as a function of the well-screen parameters results in more precise estimates for our test conditions.
Dissertation or thesis originally submitted to ProQuest.
Joshi, Bisesh, "Estimation of Hydraulic Conductivity from Injection Tests using Mini-Piezometers with Drilled-Hole Screens" (2022). Electronic Theses and Dissertations. 3266.