Green, W. R.. U.S. Geological Survey, wrgreen@usgs.gov
, . R.. ,

 
USE OF RELATIONS BETWEEN RESERVOIR FLUSHING RATE AND WATER QUALITY TO IMPROVE WATER-QUALITY ASSESSMENT
 
The objective of this study was to test if the relations between resservoir flushing rate and several water quality parameters could be used to improve assessment of reservoir water-quality conditions and trends. The data set used in this investigation is from four reservoirs located in the White River Basin of northern Arkansas and southern Missouri. The U.S. Geological Survey collected data at 17 sites for the U.S. Army Corps of Engineers between 1974 and 1995. Flushing-rate and water-quality relations were identified at sites within each reservoir. Inflow or outflow flushing rate time periods that provided the best least-squares fit between flushing rate and water-quality values were identified and used to evaluate water-quality conditions and determine flushing-rate-adjusted values. Flushing-rate-adjusted trends were compared with unadjusted trends to better resolve water-quality changes through time. Identifying relations between reservoir flushing rate and water quality improved water-quality assessment. Negative relations between inflow flushing rates and chlorophyll a and nutrients at upstream sites on two reservoirs helped identify point sources of nutrients. Areal hypolimnetic oygen deficits in forebays were positively related to outflow flushing rates. By removing the effect of flushing rate variability on water-quality values, flushing-rate-adjusted trends were identified that were not identified using unadjusted data.
 
Day: Tuesday, Feb. 2
Time: 11:30 - 11:45am
Location: Sweeney Center
 
Code: SS19TU1130S