Examining Nutrient Export from a Snowfall Dominated Watershed
Location
Eccles Conference Center
Event Website
http://water.usu.edu/
Start Date
4-20-2010 1:20 PM
End Date
4-20-2010 1:40 PM
Description
Pineview Reservoir is situated in the Ogden Valley, approximately eight miles east of Ogden City, Utah. Conditions during late summer lead to anaerobiosis in the hypolimnion of the reservoir. The TMDL for this reservoir identifies both nitrogen and phosphorus as limiting nutrients in primary production and attributes 23% and 48% of dissolved nitrogen and phosphorus, respectively, to tributary loadings. The watershed is typical of the intermountain west since the dominant portion of water carried by streams is from snowmelt. Snowmelt events are frequently associated with the highest rates of nutrient export from the watershed; however, estimates of these rates have a broad range and there is a need to quantify locally-specific rates of nutrient loss. In an effort to identify and quantify sources of nutrients transported to the reservoir via surface water, two reaches from the same headwater but under the influence of different landscapes are being monitored using direct and surrogate measurement techniques. Periodic sampling involves analyses for nutrients including forms of phosphorus and nitrogen, as well as pH, specific conductance, and turbidity. Flow rates are also measured at the same time as sample collection. Turbidity, conductivity, and water level are recorded at half-hour intervals. As total phosphorus export is commonly associated with erosion events, an attempt to correlate in-stream phosphorus concentrations with turbidity will be made at each of the four monitoring locations. Conductivity will be used to examine surface water/groundwater exchange. Water levels will be correlated with measured flow rates in an effort to determine stage-discharge relationships. Preliminary data show the dissimilar nature of the hydrology and water quality of the two reaches as the snowmelt season progresses. Data patterns observed thus far reflect the runoff associated with lower elevation precipitation. It is anticipated that future data will be indicative of nutrient export rates associated with the landscapes draining to the monitored reaches.
Examining Nutrient Export from a Snowfall Dominated Watershed
Eccles Conference Center
Pineview Reservoir is situated in the Ogden Valley, approximately eight miles east of Ogden City, Utah. Conditions during late summer lead to anaerobiosis in the hypolimnion of the reservoir. The TMDL for this reservoir identifies both nitrogen and phosphorus as limiting nutrients in primary production and attributes 23% and 48% of dissolved nitrogen and phosphorus, respectively, to tributary loadings. The watershed is typical of the intermountain west since the dominant portion of water carried by streams is from snowmelt. Snowmelt events are frequently associated with the highest rates of nutrient export from the watershed; however, estimates of these rates have a broad range and there is a need to quantify locally-specific rates of nutrient loss. In an effort to identify and quantify sources of nutrients transported to the reservoir via surface water, two reaches from the same headwater but under the influence of different landscapes are being monitored using direct and surrogate measurement techniques. Periodic sampling involves analyses for nutrients including forms of phosphorus and nitrogen, as well as pH, specific conductance, and turbidity. Flow rates are also measured at the same time as sample collection. Turbidity, conductivity, and water level are recorded at half-hour intervals. As total phosphorus export is commonly associated with erosion events, an attempt to correlate in-stream phosphorus concentrations with turbidity will be made at each of the four monitoring locations. Conductivity will be used to examine surface water/groundwater exchange. Water levels will be correlated with measured flow rates in an effort to determine stage-discharge relationships. Preliminary data show the dissimilar nature of the hydrology and water quality of the two reaches as the snowmelt season progresses. Data patterns observed thus far reflect the runoff associated with lower elevation precipitation. It is anticipated that future data will be indicative of nutrient export rates associated with the landscapes draining to the monitored reaches.
https://digitalcommons.usu.edu/runoff/2010/AllAbstracts/16