Seasonality in spatial variability and influence of land use/land cover and watershed characteristics on stream water nitrate concentrations in a developing watershed in the Rocky Mountain West

Abstract

[1] In recent decades, the Rocky Mountain West has been one of the fastest growing regions in the United States. Headwater streams in mountain environments may be particularly susceptible to nitrogen enrichment from residential and resort development. We utilized stream water chemistry from six synoptic sampling campaigns combined with land use/land cover (LULC) and terrain analysis in geostatistical modeling to examine the spatial and seasonal variability of LULC impacts on stream water nitrate. Stream water nitrate was spatially correlated for longer distances during the dormant season than during the growing season, suggesting the importance of biological retention. Spatial linear models indicated that anthropogenic sources best predicted stream water nitrate in the dormant season, while variables describing biological processing were the best predictors in the growing season. This work demonstrates the importance of (1) incorporating spatial relationships into water quality modeling and (2) investigating stream water chemistry across seasons to gain a more complete understanding of development impacts on stream water quality.

Integrated management of ash from industrial and domestic combustion: a new sustainable approach for reducing greenhouse gas emissions from energy conversion

“…In the case of nitrogen compounds, their concentrations are clearly affected by the biological activity of the catchment. This is because during the growing period, nitrogen is assimilated by plants and the concentrations of its compounds are significantly lower, which is confirmed by other studies (Gardner and McGlynn 2009;Halliday et al 2013). In turn, higher concentrations of nitrogen compounds are observed in autumn and winter, when the biological activity is definitely lower.…”

Network analysis reveals multiscale controls on streamwater chemistry

“…Furthermore, the spatial structure of stream network chemistry that emerges from our analysis is similar to patterns that have been observed in landscape ecology, where both broad-scale gradients and fine-scale patchiness are influenced by environmental attributes (33). Semivariograms of water chemistry in the stream network of the Hubbard Brook Valley revealed spatial structure at multiple scales previously described only in unbranched stream sections (11) or for a limited suite of chemical constituents examined at much coarser scales (34). Other pioneering studies of stream networks have examined spatial heterogeneity or developed predictive models in stream networks (16,35), but these studies have been too coarse in grain (low resolution) to detect spatial structure at scales ranging from hundreds to thousands of meters.…”

Climate change, aquatic ecosystems, and fishes in the Rocky Mountain West: implications and alternatives for management

“…Using these new statistical techniques in conjunction with a large stream temperature database (n = 780) compiled from several resource agencies, Isaak and others (2010) built stream temperature models that explained 93 percent of the variation in temperatures over a 13-year period across an extensive river network. Similar results have been achieved using spatial stream techniques with other water quality attributes (Gardner and McGlynn 2009;Peterson and Urquhart 2006) and fish population attributes , and those results suggest a future wherein bioclimatic relationships in streams can be examined in great detail (McIntire and Fajardo 2009).…”