My WebLink
|
Help
|
About
|
Sign Out
Home
Browse
Search
WSP08317
CWCB
>
Water Supply Protection
>
Backfile
>
8001-9000
>
WSP08317
Metadata
Thumbnails
Annotations
Entry Properties
Last modified
1/26/2010 2:47:44 PM
Creation date
10/12/2006 2:53:38 AM
Metadata
Fields
Template:
Water Supply Protection
File Number
8200.760
Description
Yampa River General
State
CO
Basin
Yampa/White
Water Division
6
Date
4/1/1978
Author
USGS
Title
Hydrologic Reconnaissance of the Yampa River During Low Flow - Dinosaur National Monument - Northwestern Colorado - April 1978
Water Supply Pro - Doc Type
Report/Study
There are no annotations on this page.
Document management portal powered by Laserfiche WebLink 9 © 1998-2015
Laserfiche.
All rights reserved.
/
13
PDF
Print
Pages to print
Enter page numbers and/or page ranges separated by commas. For example, 1,3,5-12.
After downloading, print the document using a PDF reader (e.g. Adobe Reader).
Show annotations
View images
View plain text
<br />002650 <br /> <br />Values greater than the lOa-percent saturation level during the day <br />result when photosynthesis of attached algae occurs at a greater rate than <br />biological respiration. Values less than the lOa-percent saturation level are <br />noted at night, when photosynthesis ceases but biological respiration <br />continues. The magnitudes of the supersaturation and undersaturation levels <br />often are ameliorated by stream turbulence, which tends to maintain an average <br />of lOa-percent saturation. Because of the long pools and relatively <br />insignificant riffles in the lower Yampa River during the time of the <br />reconnaissance, this effect was minimal. Thus, the degree of supersaturation <br />and undersaturation with respect to dissolved oxygen indicates that biological <br />activity was not great. <br /> <br />The above conclusion is corroborated by the relatively small range of pH <br />(8.4 to 8.8) that was observed. In areas where biological activity is great, <br />photosynthesis raises the pH during the day, whereas respiration lowers it at <br />night. The actual pH values in the study reach compare quite favorably to the <br />median pH of 8.4 (D. A. Wentz and T. D. Steele, written Commun., 1978) <br />measured in the Yampa River basin upstream from Dinosaur National. monument <br />during August-September 1976. Although it might be argued that pH's in the <br />study reach were slightly larger than those measured upstream, this could be <br />explained by dissolution of dolomite and limestone in the monument area. <br /> <br />Decreases in streamflow, on the order of 4 to 11 percent, were measured <br />in a downstream direction in the study reach from site 1 to site 17. This <br />downstream trend was apparent in spite of the estimated accuracy of tl0 <br />percent for any single measurement. From site 17 to site 43 at the mouth of <br />the Yampa River, streamflow increased from 1 to 7 percent. A net downstream <br />decrease in stream discharge of 0.5 m3/s (equal to 5 percent) was measured in <br />the study reach. Variations in streamflow probably are due to a combination <br />of. effects, including unmeasured underflow in sandy parts of the stream <br />channel, recharge to or discharge from ground-water aquifers transversing the <br />stream channel, and evaporation. <br /> <br />The results of the analyses for trace elements in bottom-sediment samples <br />(table 1) were compared with results for samples collected at sites upstream <br />from the monument that were not affected by water-quality degradation. during <br />August-September 1976 (D. A. Wentz and. T. D. Steele, written commun., 1978). <br />Except for mercury, all bottom-sediment trace-element conce.ntrations were less <br />than the corresponding maximum concentration observed for streams of the Yampa <br />River basin. However, one mercury concentration In bottom sediments of the <br />Yampa River in Dinosaur National Monument was greater than the maximum <br />recorded in bottom sediments throughout the rest of the basin upstream from <br />the study reach. <br /> <br />The maximum concentrations of all trace elements sampled occurred at <br />site 8, and all have secondary maximums at site 28. The maximum <br />concentrations at site 8 might be explained by a source upstream from this <br />point, but downstream from site 1. Easily eroded shales that crop out in the <br />eastern part of the monument, but which do not crop out in the Yampa River <br /> <br />8 <br /> <br />,$ <br />
The URL can be used to link to this page
Your browser does not support the video tag.