Date of this Version
Published in Groundwater 49:6 (November/December 2011), pp. 920–925; doi: 10.1111/j.1745-6584.2010.00796.x
A borehole permeameter is well suited for testing saturated hydraulic conductivity (Ksat) at specific depths in the vadose zone. Most applications of the method involve fine-grained soils that allow hand auguring of test holes and require a small water reservoir to maintain a constant head. In non-cohesive gravels, hand-dug test holes are difficult to excavate, holes are prone to collapse, and large volumes of water are necessary to maintain a constant head for the duration of the test. For coarse alluvial gravels, a direct-push steel permeameter was designed to place a slotted pipe at a specific sampling depth. Measurements can be made at successive depths at the same location. A 3790 L (1000 gallons) trailer-mounted water tank maintained a constant head in the permeameter. Head in the portable tank was measured with a pressure transducer and flow was calculated based on a volumetric rating curve. A U.S. Bureau of Reclamation analytical method was utilized to calculate Ksat. Measurements with the permeameter at a field site were similar to those reported from falling-head tests.
Includes Supplementary materials.