کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6412707 | 1629935 | 2014 | 6 صفحه PDF | دانلود رایگان |

- We conduct mass balance analyses for riverine nitrate passing through a reservoir.
- Our results are consistent with others spanning a wide range of retention times.
- Percent nitrate removal is a predictable function of hydraulic loading rate.
- Mass nitrate removal is a function of percent removal and mass loading.
- These results apply to reservoirs having moderate to high input concentrations.
SummaryFew studies have quantified nitrate-nitrogen reductions in rivers flowing through large flood control reservoirs despite their potential role in helping to meet nitrate-N load reduction targets. In this study, we evaluated a 26-year record of nitrate-N monitoring in Saylorville Lake reservoir that impounds the Des Moines River in central Iowa to estimate the annual mass of nitrate-N removed and evaluate controls on inter-annual patterns of nitrate-N removal rates. Results from mass balance calculations indicate a nitrate mass loss of 4.9% over the 26Â year period from 1986 through 2011. The annual percent nitrate mass removed is related to hydraulic loading rate with low flow years having longer retention times removing a significantly greater percentage of nitrate than is removed during high flow years with low retention times. Average annual residence times varied from 3.5 to 74Â days with a 26Â year average of 9.7Â days. Nitrate removal results for Saylorville Lake agree well with published work for several other reservoirs which together encompass a broad range of nitrate removal rates. Combining data from Saylorville Lake with other published studies, a relationship between nitrate-N removal rate and hydraulic loading rate was developed resulting in a predictive equation with a model R2Â =Â 0.92.
Journal: Journal of Hydrology - Volume 513, 26 May 2014, Pages 1-6