Jj. Warwick et al., Modeling the impact of subsurface nutrient flux on water quality in the Lower Truckee River, Nevada, J AM WAT RE, 35(4), 1999, pp. 837-851
Citations number
34
Categorie Soggetti
Environment/Ecology
Journal title
Journal of the american water resources association
The impacts of regional groundwater quality and local agricultural activiti
es on in-stream water quality in the Lower Truckee River, Nevada, were asse
ssed through a detailed program of monitoring and computer simulation. An a
gricultural diversion and return-flow were monitored in great detail to det
ermine mass loading rates of nutrients from agriculture in the area. Once c
haracterized, the cumulative impacts of agricultural diversions and return-
flows were evaluated using the Water Quality Assessment Program (WASP) to m
odel nitrogen, phosphorus, periphyton, and dissolved oxygen. Monitoring sho
wed that a significant proportion of the water diverted for agricultural pu
rposes returned to the river as surface point return-flow (estimated at 13.
9 percent +/- 0.1 percent), and as groundwater diffuse return-flow (estimat
ed at 27 percent +/- 6 percent). Modeling efforts demonstrated the signific
ant effect of assumed regional groundwater quality (nitrate) upon predicted
periphyton growth and associated diel fluctuations of dissolved oxygen.