 |
Tuesday, May 27, 2008 - 9:45 AM
138
Seasonality in spatial patterns of stream network nitrate concentrations in a developing mountain watershed in the Rocky Mountain west
Kristin K. Gardner and Brian L. McGlynn. Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, MT 59717
Identifying the primary controls on the seasonality of spatial heterogeneity in streamwater nitrogen (N) represents a fundamental gap in understanding of land use/land cover change impacts on watershed N export. We conducted six synoptic sampling campaigns in the 212 km2West Fork watershed, which drains the rapidly developing Big Sky area, Montana. Synoptic sampling captured a wide range of hydrologic conditions and biologic potential . Results indicated strong spatial variability of nitrate (NO3-) concentrations within and across synoptic events. Median NO3- concentrations were highest in winter (February = 0.17 mg/L-N and March = 0.14 mg/L-N). Semivariograms indicated spatial correlation seasonality of network NO3- concentrations; there was strong spatial structure in the dormant season and little in the growing season. Additionally, General linear models to predict NO3- indicated seasonal differences in primary drivers. During the growing season, biologic activity/immobilization along upland and riparian flowpaths, and within the stream network were key controls on N spatial variability, while in the dormant season N loading dominated the N signal.
Web Page: nitrogen, watershed, spatial analysis
See more of Hydrologic Processes I
See more of Contributed Sessions
See more of The Nabs 56th Annual Meeting (25-28 May, 2008)
See more of Contributed Sessions
See more of The Nabs 56th Annual Meeting (25-28 May, 2008)