Stream bed temperature profiles as indicators of percolation characteristics beneath arroyos in the Middle Rio Grande Basin, USA
✍ Scribed by Jim Constantz; Carole L. Thomas
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 394 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0885-6087
No coin nor oath required. For personal study only.
✦ Synopsis
Stream bed temperature pro®les were monitored continuously during water year 1990 and 1991 (WY90 and 91) in two New Mexico arroyos, similar in their meteorological features and dissimilar in their hydrological features. Stream bed temperature pro®les between depths of 30 and 300 cm were examined to determine whether temporal changes in temperature pro®les represent accurate indicators of the timing, depth and duration of percolation in each stream bed. These results were compared with stream ¯ow, air temperature, and precipitation records for WY90 and 91, to evaluate the eect of changing surface conditions on temperature pro®les. Temperature pro®les indicate a persistently high thermal gradient with depth beneath Grantline Arroyo, except during a semi-annual thermal reversal in spring and autumn. This typi®es the thermal response of dry sediments with low thermal conductivities. High thermal gradients were disrupted only during infrequent stream ¯ows, followed by rapid re-establishment of high gradients. The stream bed temperature at 300 cm was unresponsive to individual precipitation or stream ¯ow during WY90 and 91. This thermal pattern provides strong evidence that most seepage into Grantline Arroyo failed to percolate at a sucient rate to reach 300 cm before being returned to the atmosphere. A distinctly dierent thermal pattern was recorded beneath Tijeras Arroyo. Low thermal gradients between 30 and 300 cm and large diurnal variations in temperature, suggest that stream ¯ow created continuous, advection-dominated heat transport for over 300 days, annually. Beneath Tijeras Arroyo, low thermal gradients were interrupted only brie¯y during periodic, dry summer conditions. Comparisons of stream ¯ow records for WY90 and 91 with stream bed temperature pro®les indicate that independent analysis of thermal patterns provides accurate estimates of the timing, depth and duration of percolation beneath both arroyos. Stream ¯ow loss estimates indicate that seepage rates were 15 times greater for Tijeras Arroyo than for Grantline Arroyo, which supports qualitative conclusions derived from analysis of stream bed temperature responses to surface conditions.