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Field verification of stream-aquifer interactions : Colorado School of Mines survey field, Golden, Colorado
| Content Provider | Semantic Scholar |
|---|---|
| Author | Poeter, Eileen P. Anderman, Evan R. |
| Copyright Year | 2007 |
| Abstract | The nature of stream/aquifer interactions is determined in a field study on a stream at the Colorado School of Mines survey field in Golden, Colorado. The field study measured the temporal and spatial variability during the spring and summer of 1992 of hydraulic parameters controlling stream/aquifer interactions at the streambed level of detail. Techniques for obtaining inexpensive measurements of the relevant parameters are developed. The field study included determination of the shallow hydraulic gradient directly beneath the stream; measurement of streambed seepage along the stream reach; in-situ hydraulic conductivity measurement using established piezometers and an air permeameter; and, characterization of the streambed. Samples were collected and grain size distribution was determined. The study area was monitored during a variety of hydrologic conditions in order to determine temporal and spatial controls on the seepage rate. A number of conclusions are drawn regarding the nature of stream/aquifer interactions at the site. As 1992 received less precipitation than 1991, groundwater did not discharge as long into 1992 as into 1991, indicating that duration of groundwater discharge into summer months is dependent on the amount of precipitation the area has received. The response of the groundwater system to precipitation is on the order of days rather than hours, while the response to changes in stream stage is almost immediate. The shallow groundwater gradients calculated from the water level data indicate the presence of two groundwater discharge zones at the site, corresponding to sharp breaks in stream slope and possible subsurface features. The total reach of stream is generally gaining water from the groundwater system. The range of stream flow velocities observed is fairly uniform and sufficient to transport unconsolidated sediments up to 2 mm in diameter. Mapping of the streambed surface material shows that it is highly variable with poorly sorted large grain sizes predominant. Grain size distribution analysis supports this observation. Measured hydraulic conductivity of the streambed surface material ranges from 2.2 x 10-6 to 3.2 x 10-4 feet per second (ft/s), while hydraulic conductivity of the shallow aquifer material is greater with a range of 9.5 x 10-6 to 4.3 x 10-4 ftls. The |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.cwi.colostate.edu/media/publications/cr/169.pdf |
| Alternate Webpage(s) | https://mountainscholar.org/bitstream/handle/10217/1027/COMP169.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
