scholarly journals Nitrogen concentrations and loads for the Connecticut River at Middle Haddam, Connecticut, computed with the use of autosampling and continuous measurements of water quality for water years 2009 to 2014

2018 ◽  
Author(s):  
John R. Mullaney ◽  
Joseph W. Martin ◽  
Jonathan Morrison
Keyword(s):  
Water Quality ◽  
Connecticut River ◽  
Continuous Measurements ◽  
Nitrogen Concentrations

Streamflow nitrogen loss following forest fertilization in a southern Vancouver Island watershed

1985 ◽  
Vol 15 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Eugene D. Hetherington
Keyword(s):  
Water Quality ◽  
Nitrogen Loss ◽  
Vancouver Island ◽  
Soil Permeability ◽  
Creek Watershed ◽  
Second Growth ◽  
Nitrogen Concentrations ◽  
Steep Slopes ◽  
Fall Application ◽  
Small Tributary

Water quality was monitored in the Lens Creek watershed on southern Vancouver Island to determine nitrogen loss following fall application of 224 kg N/ha urea fertilizer on a second-growth Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) forest. Peak nitrogen concentrations measured in two small tributary streams were 14 mg/L as urea, 1.9 mg/L as ammonia, and 9.3 mg/L as nitrate. For the first 14 months, estimated nitrogen outputs in excess of background amounts were 5.9 and 14.5% of the total applied nitrogen for the two subsidiary watersheds with 46 and 80% of their drainage areas fertilized, respectively. These losses were considerably higher than amounts of less than 1% previously reported for western North America. Increased levels of urea N and ammonia N were short-lived, while nitrate N remained above background levels for the study duration. Reasons for the high nitrogen loss include nitrification of the urea during 7 weeks of mild, dry weather following fertilization, presence of alder and swampy areas adjacent to the streams, high soil permeability, steep slopes, and abundant, above average early winter rainfall. The watersheds had been previously fertilized, but any influence of this first fertilization on nitrogen loss during the present study is unknown. Lens Creek water quality was not adversely affected by the fertilization in terms of drinking water standards or toxicity to fish.

scholarly journals Modelling of nitrogen concentrations in water from drained peat soils

2019 ◽  
Vol 69 (3) ◽  
pp. 288-297 ◽  
Author(s):  
Anatoli Vassiljev ◽  
Ivar Annus ◽  
Nils Kändler ◽  
Katrin Kaur
Keyword(s):  
Water Quality ◽  
Significant Source ◽  
Agricultural Activity ◽  
Large Share ◽  
Peat Soils ◽  
Nitrate Concentrations ◽  
Nitrogen Concentrations ◽  
Improve Water Quality ◽  
Model Water

Abstract In addition to traditional sources, drained peat soils have been found to be a significant source of nitrogen in Estonia. As a result, supplementary measures are required to improve water quality in rivers. Modelling is a widespread method to select means for improving water quality. At present, modelling of nitrogen in rivers has been concentrated on the influence of agricultural activity. However, drained peat can increase nitrogen concentrations even without fertilization and farming activities. This investigation describes the attempt to model water quality in the watershed with a large share of drained peat soils. The results showed a good alignment between measured and modelled nitrate concentrations using the MACRO and the SOILN for MACRO models. Some measures to improve water quality were tested using these models.

scholarly journals Modelling of the Effect of Drained Peat Soils to Water Quality Using MACRO and SOILN Models

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 619 ◽  
Author(s):  
Anatoli Vassiljev ◽  
Ivar Annus ◽  
Nils Kändler ◽  
Katrin Kaur
Keyword(s):  
Water Quality ◽  
Significant Source ◽  
Agricultural Activity ◽  
Large Share ◽  
Peat Soils ◽  
Nitrate Concentrations ◽  
Nitrogen Concentrations ◽  
Improve Water Quality ◽  
Model Water

Investigations have indicated that in addition to traditional sources, drained peat soils can be considered as a significant source of nitrogen in Estonia. This changes the measures to improve water quality in rivers. At present modelling of nitrogen in rivers has been concentrated on influence of agricultural activity. However, drained peat can increase nitrogen concentrations even without fertilization and farming activities. This investigation describes the attempt to model water quality in the watershed with large share of drained peat soils. A good alignment between measured and modelled nitrate concentrations using the MACRO and the SOILN for MACRO models was shown.

Biological and physicochemical characteristics of the Ross River Dam, Townsville

1982 ◽  
Vol 33 (5) ◽  
pp. 811 ◽  
Author(s):  
CM Finlayson ◽  
JC Gillies
Keyword(s):  
Water Quality ◽  
Water Level ◽  
Chlorophyll A ◽  
Aquatic Vegetation ◽  
Physicochemical Characteristics ◽  
Artificial Lake ◽  
Management Planning ◽  
Nitrogen Concentrations ◽  
Low Nitrogen ◽  
Future Management

The biological and physicochemical characteristics of the Ross River Dam, an artificial lake near Townsville in northern Queensland, are described. The lake is characterized by a sodium and chloride ionic dominance, may be polymictic, and contains a relatively low ratio of total phosphorus to total nitrogen due to the low nitrogen concentrations. The aquatic vegetation is widespread and dominated by the submerged Hydrilla verricillata and Potamogeton javanicus. Both species are plentiful in the lake but are not, at present, major weeds. The phytoplankton were not found in bloom conditions despite chlorophyll a concentrations near 10 mg m-3. The main fish species of 11 recorded was Glossamia gilli. The results from this survey will provide a useful basis for future management planning, especially if the water level or water-quality conditions were to vary.

scholarly journals Long-Term Impacts of Reservoir Operation on the Spatiotemporal Variation in Nitrogen Forms in the Post-Three Gorges Dam Period (2004–2016)

2021 ◽  
Author(s):  
Bei Nie ◽  
Yuhong Zeng ◽  
Lanhua Niu ◽  
Xiaofeng Zhang
Keyword(s):  
Water Quality ◽  
Reservoir Operation ◽  
Yangtze River ◽  
Ammonia Nitrogen ◽  
Three Gorges ◽  
The Yangtze River ◽  
Engineering Construction ◽  
Nitrogen Concentrations ◽  
Essential Nutrient

Abstract Nitrogen (N) is an essential nutrient limiting life, and its biochemical cycling and distribution in rivers have been markedly affected by river engineering construction and operation. Here, we comprehensively analyzed the spatiotemporal variations and driving environmental factors of N distributions based on the long-term observations (from 2004 to 2016) of seven stations in the Three Gorges Reservoir (TGR). In the study period, the overall water quality status of the river reach improved, whereas N pollution was severe and tended to be aggravated after the TGR impoundment. The anti-seasonal reservoir operation strongly affected the variations in N forms. The total nitrogen (TN) concentration in the mainstream of the Yangtze River continuously increased, although it was still lower than that in the incoming tributaries (Wu and Jialing rivers). Further analysis showed that this increase occurred probably because of external inputs, including the upstream (76%), non-point (22%), and point source pollution inputs (2%). Besides, different N forms showed significant seasonal variations; among them, the TN and nitrate nitrogen concentrations were the lowest in the impoundment season (October–February), and the ammonia nitrogen concentrations were the highest in the sluicing season (March–May). These parameters varied likely because of internal N transformation. Redundancy analysis revealed that the water level regulated by the anti-seasonal operation was the largest contributor. Our findings could provide a basis for managing and predicting the water quality in the Yangtze River.

scholarly journals Dispersed urban-stormwater control improved stream water quality in a catchment-scale experiment

2021 ◽  
Author(s):  
Christopher John Walsh ◽  
Sam Imberger ◽  
Matthew J Burns ◽  
Darren G Bos ◽  
Tim D Fletcher
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Control Measure ◽  
Urban Streams ◽  
Septic Tank ◽  
Stream Water Quality ◽  
Urban Stormwater ◽  
Catchment Scale ◽  
Nitrogen Concentrations ◽  
Stormwater Control

Traditional approaches to urban drainage degrade receiving waters. Alternative approaches have potential to protect downstream waters and provide other benefits to cities, including greater water security. Their widespread adoption requires robust demonstration of their feasibility and effectiveness. We conducted a catchment-scale, before-after-control-reference-impact experiment to assess the effect of dispersed stormwater control on stream ecosystems. We used a variant of effective imperviousness (EI), integrating catchment-scale stormwater runoff impact and stormwater-control-measure (SCM) performance, as the measure of experimental effect. We assessed the response of water quality variables in 6 sites on 2 streams, following SCM implementation in their catchments. We compared changes in those streams over 7 years, as SCM implementation increased, to the 12 preceding years, and over the 19 years in 3 reference and 2 control streams. SCMs reduced phosphorus and nitrogen concentrations and temperature, and increased electrical conductivity; with effect size negatively correlated with antecedent rain. SCM-induced reductions in phosphorus and temperature were of a similar magnitude to increases from urban development, when assessed as a function of change in EI. Nitrogen reductions were observed, even though concentrations among sites were not correlated with EI, being more influenced by septic tank seepage. SCMs had no effect on suspended solids concentrations, which were lower in urban streams than in reference streams. This experiment strengthens the inference that urban stormwater drainage increases contaminant concentrations in urban streams, and demonstrates that such impacts are reversible and likely preventable. SCMs reduce contaminant concentrations by reducing the frequency and magnitude of uncontrolled drainage flows and augmenting reduced baseflows. Increased EC and reduced temperature are likely a result of increased contribution of groundwater to baseflows. The stormwater control achieved by the experiment did not fully return phosphorus or nitrogen concentrations to reference levels, but their responses indicate such an outcome is possible in dominant conditions (up to ~20 mm of 24-h antecedent rain). This would require nearly all impervious surfaces draining to SCMs with large retention capacity, thus requiring more downslope space and water demand. EI predicts stream water quality responses to SCMs, allowing better catchment prioritization and SCM design standards for stream protection.

scholarly journals Land Use and Stream Nitrogen Concentrations in Agricultural Watersheds Along the Central Coast of California

2001 ◽  
Vol 1 ◽  
pp. 615-622 ◽  
Author(s):  
Marc Los Huertos ◽  
Lowell E. Gentry ◽  
Carol Shennan
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Shallow Groundwater ◽  
Surface Water Quality ◽  
Spatial And Temporal Patterns ◽  
Total N ◽  
Nitrogen Concentrations ◽  
High Concentrations ◽  
N Loading

In coastal California nitrogen (N) in runoff from urban and agricultural land is suspected to impair surface water quality of creeks and rivers that discharge into the Monterey Bay Sanctuary. However, quantitative data on the impacts of land use activities on water quality are largely limited to unpublished reports and do not estimate N loading. We report on spatial and temporal patterns of N concentrations for several coastal creeks and rivers in central California. During the 2001 water year, we estimated that the Pajaro River at Chittenden exported 302.4 Mg of total N. Nitrate-N concentrations were typically <1 mg N l–1in grazing lands, oak woodlands, and forests, but increased to a range of 1 to 20 mg N l–1as surface waters passed through agricultural lands. Very high concentrations of nitrate (in excess of 80 mg N l–1) were found in selected agricultural ditches that received drainage from tiles (buried perforated pipes). Nitrate concentrations in these ditches remained high throughout the winter and spring, indicating nitrate was not being flushed out of the soil profile. We believe unused N fertilizer has accumulated in the shallow groundwater through many cropping cycles. Results are being used to organize landowners, resource managers, and growers to develop voluntary monitoring and water quality protection plans.

scholarly journals Distribution and abundance of Chironomidae (Diptera, Insecta) in an impacted watershed in South-east Brazil

1999 ◽  
Vol 59 (4) ◽  
pp. 553-561 ◽  
Author(s):  
M. M. G. S. M. MARQUES ◽  
F. A. R. BARBOSA ◽  
M. CALLISTO
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Principal Component ◽  
Total Alkalinity ◽  
Pollution Levels ◽  
Sampling Points ◽  
Genus Richness ◽  
Nitrogen Concentrations ◽  
Chironomid Midges ◽  
Abundant Genus

Patterns of abundance and distribution of chironomid midges (Diptera, Chironomidae) in the middle Rio Doce basin were analysed. Human activities (mining, steel processing, and Eucalyptus spp. forestry) contribute to environmental degradation and low water quality in this watershed. Physical and chemical water traits (dissolved oxygen, pH, total alkalinity, electric conductivity, phosphorus and nitrogen concentrations) of 20 sampling points were used in a Principal Component Analysis (PCA) to establish the best and worst water quality. Sampling points recorded as the most polluted showed low genus richness of Chironomidae, less than five genera from the total 23, and dominance of the genus Chironomus, a bioindicator of environmental stress. Following Chironomus, the second most frequent and abundant genus was Cricotopus, whose distribution could not be related to pollution levels. The Tanypodinae sub-family showed certain sensitivity to low dissolved oxygen concentrations and high nutrients levels, and was not found at points of high pollution levels.

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