The upside-down river: Reservoirs, algal blooms, and tributaries affect temporal and spatial patterns in nitrogen and phosphorus in the Klamath River, USA

Oliver, A. J.; Dahlgren, Randy A.; Deas, Michael L.

doi:10.1016/j.jhydrol.2014.06.025

Cited by 43 publications

(21 citation statements)

References 50 publications

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“…The weaker correlations in our study for nitrate compared to phosphate may have resulted from the more dynamic nature of nitrate cycling (with respect to phosphate) in small waterbodies. The study areas covered a range of climate conditions, with large differences in temperature, residence time, oxygen conditions, groundwater inputs and surface temperatures, all with important impacts on dissolved nitrate dynamics [ 42 – 44 ]. As these variables were not evaluated in the present study, key drivers of nitrate dynamics were left out of the present analysis.…”

Section: Discussionmentioning

confidence: 99%

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America

et al. 2016

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Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = –0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river ecosystems.

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Section: Discussionmentioning

confidence: 99%

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America

et al. 2016

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“…In our system, water depth covaried with water clarity (Figure 4), largely as a result of the tributaries entering the Klamath River below Iron Gate Dam which tend to contribute relatively clearer water to the main stem, creating higher water clarity with distance downstream from the dam [75]. Deepening river channels created by high winter flows follow a similar longitudinal trend associated with these tributary inputs [76].…”

Section: Uav Monitoring Of Benthic Primary Producersmentioning

confidence: 93%

Application of UAV Imagery to Detect and Quantify Submerged Filamentous Algae and Rooted Macrophytes in a Non-Wadeable River

et al. 2020

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Imagery from unoccupied aerial vehicles (UAVs) is useful for mapping floating and emerged primary producers, as well as single taxa of submerged primary producers in shallow, clear lakes and streams. However, there is little research on the effectiveness of UAV imagery-based detection and quantification of submerged filamentous algae and rooted macrophytes in deeper rivers using a standard red-green-blue (RGB) camera. This study provides a novel application of UAV imagery analysis for monitoring a non-wadeable river, the Klamath River in northern California, USA. River depth and solar angle during flight were analyzed to understand their effects on benthic primary producer detection. A supervised, pixel-based Random Trees classifier was utilized as a detection mechanism to estimate the percent cover of submerged filamentous algae and rooted macrophytes from aerial photos within 32 sites along the river in June and July 2019. In-situ surveys conducted via wading and snorkeling were used to validate these data. Overall accuracy was 82% for all sites and the highest overall accuracy of classified UAV images was associated with solar angles between 47.5 and 58.72° (10:04 a.m. to 11:21 a.m.). Benthic algae were detected at depths of 1.9 m underwater and submerged macrophytes were detected down to 1.2 m (river depth) via the UAV imagery in this relatively clear river (Secchi depth > 2 m). Percent cover reached a maximum of 31% for rooted macrophytes and 39% for filamentous algae within all sites. Macrophytes dominated the upstream reaches, while filamentous algae dominated the downstream reaches closer to the Pacific Ocean. In upcoming years, four proposed dam removals are expected to alter the species composition and abundance of benthic filamentous algae and rooted macrophytes, and aerial imagery provides an effective method to monitor these changes.

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“…It computes water surface elevations and horizontal velocity components for subcritical, free-surface flow in two-dimensional flow fields [13]. The RMA2 model is frequently used in physical oceanography to represent processes such as tides and currents in coastal regions and estuaries, its use has been documented by [14][15][16][17][18][19][20][21]. RMA2 solves the depth-averaged equations of fluid mass and momentum conservation in two horizontal directions.…”

Section: Implementation Of the Modelmentioning

confidence: 99%

Effect of bathymetric changes on residence time in Buenaventura bay (Colombia)

Rentería

Chirino

2019

DYNA

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In order to study the effects of dredging on the residence time of the water in Buenaventura Bay, a 2D finite elements hydrodynamic model was coupled with a particle tracking model. After calibrating and validating the hydrodynamic model, two scenarios that represented the bathymetric changes generated by the dredging process were simulated. The results of the comparison of the simulated scenarios, showed an important reduction in the velocities fields that allow an increase of the residence time up to 12 days in some areas of the bay. In the scenario without dredging, that is, with original bathymetry, residence times of up to 89 days were found.

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The upside-down river: Reservoirs, algal blooms, and tributaries affect temporal and spatial patterns in nitrogen and phosphorus in the Klamath River, USA

Cited by 43 publications

References 50 publications

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America

Application of UAV Imagery to Detect and Quantify Submerged Filamentous Algae and Rooted Macrophytes in a Non-Wadeable River

Effect of bathymetric changes on residence time in Buenaventura bay (Colombia)

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