The impact of changes in nutrient loading on cyanobacterial dominance in Lake Peipsi (Estonia/ Russia)

2004 ◽  
Vol 160 (2) ◽  
pp. 261-279 ◽  
Author(s):  
T. Nõges ◽  
I. Tõnno ◽  
R. Laugaste ◽  
E. Loigu ◽  
B. Skakalski
Keyword(s):  
Nutrient Loading ◽  
Lake Peipsi ◽  
The Impact ◽  
Cyanobacterial Dominance

Predicting change in biogeochemical potential of subsurface systems with changing hydrogeological conditions

2021 ◽  
Author(s):  
Swamini Khurana ◽  
Falk Heße ◽  
Martin Thullner
Keyword(s):  
Water Quality ◽  
Preferential Flow ◽  
Nutrient Loading ◽  
Temporal Dynamics ◽  
Reaction Network ◽  
Climate Scenario ◽  
Ecosystem Functions ◽  
External Forcing ◽  
Spatio Temporal ◽  
The Impact

<p>In a changing climate scenario, we expect weather event patterns to change, both in frequency and in intensity. The subsequent impacts of these changing patterns on ecosystem functions are of great interest. Water quality particularly is critical due to public health concerns. Already, seasonal variation of water quality has been attributed to varying microbial community assemblages and nutrient loading in the corresponding water body but the contribution of the variations in the quantity of groundwater recharge is a missing link. It is thus beneficial to establish links between external forcing such as changing infiltration rate or recharge on nutrient cycling in the subsurface. We undertake this study to investigate the impact of temporal variation in external forcing on the biogeochemical potential of spatially heterogeneous subsurface systems using a numerical modeling approach. We used geostatistical tools to generate spatial random fields by considering difference combinations of the variance in the log conductivity field and the anisotropy of the domain. Tuning these two parameters assists in effective representation of a wide variety of geologic materials with varying intensity of preferential flow paths in the heterogeneous domain. We ran simulations using OGS#BRNS that enables us to combine a flexibly defined microbial mediated reaction network with the mentioned spatially heterogeneous domains in transient conditions. We propose that a combination of estimated field indicators of Damköhler number, Peclet number (transformed Damköhler number: Da<sub>t</sub>), and projected temporal dynamics in surface conditions can assist us in predicting the change in biogeochemical potential of the subsurface system. Preliminary results indicate that we miss potentially critical variations in reactive species concentration if we neglect spatio-temporal heterogeneities for regimes where 1<Da<sub>t</sub><40. For regimes characterized by values outside this range, we propose that spatio-temporal heterogeneities due to subsurface structure and changing hydrological forcing may not be relevant.</p>

Neural networks modelling of streamflow, phosphorus, and suspended solids: application to the Canadian Boreal forest

2006 ◽  
Vol 53 (10) ◽  
pp. 91-99 ◽  
Author(s):  
M.H. Nour ◽  
D.W. Smith ◽  
M. Gamal El-Din ◽  
E.E. Prepas
Keyword(s):  
Suspended Solids ◽  
Nutrient Loading ◽  
Meteorological Data ◽  
Low Cost ◽  
Toxin Production ◽  
Oxygen Depletion ◽  
Climate Change Scenarios ◽  
Careful Manipulation ◽  
Canadian Boreal Forest ◽  
The Impact

Sediment has long been identified as an important vector for the transport of nutrients and contaminants such as heavy metals and microorganisms. The respective nutrient loading to water bodies can potentially lead to dissolved oxygen depletion, cyanobacteria toxin production and ultimately eutrophication. This study proposed an artificial neural network (ANN) modelling algorithm that relies on low cost readily available meteorological data for simulating streamflow (Q), total suspended solids (TSS) concentration, and total phosphorus (TP) concentration. The models were applied to a 130-km2 watershed in the Canadian Boreal Plain. Our results demonstrated that through careful manipulation of time series analysis and rigorous optimization of ANN configuration, it is possible to simulate Q, TSS, and TP reasonably well. R2 values exceeding 0.89 were obtained for all modelled data cases. The proposed models can provide real time predictions of the modelled parameters, can answer questions related to the impact of climate change scenarios on water quantity and quality, and can be implemented in water resources management through Monte Carlo simulations.

Sediment microbes mediate the impact of nutrient loading on blue carbon sequestration by mixed seagrass meadows

2017 ◽  
Vol 599-600 ◽  
pp. 1479-1484 ◽  
Author(s):  
Songlin Liu ◽  
Zhijian Jiang ◽  
Jingping Zhang ◽  
Yunchao Wu ◽  
Xiaoping Huang ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Nutrient Loading ◽  
Blue Carbon ◽  
Seagrass Meadows ◽  
The Impact ◽  
Sediment Microbes

scholarly journals Long-Term Biosolids Application on Land: Beneficial Recycling of Nutrients or Eutrophication of Agroecosystems?

Soil Systems ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 9
Author(s):  
Murray B. McBride
Keyword(s):  
Trace Metals ◽  
Organic Carbon ◽  
Nutrient Loading ◽  
Agricultural Soils ◽  
Soil Health ◽  
Water Soluble ◽  
Amended Soils ◽  
The Impact ◽  
Biosolids Application

The impact of repeated application of alkaline biosolids (sewage sludge) products over more than a decade on soil concentrations of nutrients and trace metals, and potential for uptake of these elements by crops was investigated by analyzing soils from farm fields near Oklahoma City. Total, extractable (by the Modified Morgan test), and water-soluble elements, including macronutrients and trace metals, were measured in biosolids-amended soils and, for comparison, in soils that had received little or no biosolids. Soil testing showed that the biosolids-amended soils had higher pH and contained greater concentrations of organic carbon, N, S, P, and Ca than the control soils. Soil extractable P concentrations in the biosolids-amended soils averaged at least 10 times the recommended upper limit for agricultural soils, with P in the amended soils more labile and soluble than the P in control soils. Several trace elements (most notably Zn, Cu, and Mo) had higher total and extractable concentrations in the amended soils compared to the controls. A radish plant assay revealed greater phytoavailability of Zn, P, Mo, and S (but not Cu) in the amended soils. The excess extractable and soluble P in these biosolids-amended soils has created a long-term source of slow-release P that may contribute to the eutrophication of adjacent surface waters and contamination of groundwater. While the beneficial effects of increased soil organic carbon on measures of “soil health” have been emphasized in past studies of long-term biosolids application, the present study reveals that these benefits may be offset by negative impacts on soils, crops, and the environment from excessive nutrient loading.

scholarly journals Remediation of Nitrogen and Phosphorus from Nursery Runoff during the Spring via Free Water Surface Constructed Wetlands

2010 ◽  
Vol 28 (4) ◽  
pp. 209-217 ◽  
Author(s):  
Sarah A. White ◽  
Milton D. Taylor ◽  
Stewart L. Chandler ◽  
Ted Whitwell ◽  
Stephen J. Klaine
Keyword(s):  
Water Quality ◽  
Water Surface ◽  
Nutrient Loading ◽  
Free Water ◽  
Surface Water Quality ◽  
Phosphorus Loading ◽  
Late Winter ◽  
Nitrogen And Phosphorus ◽  
Free Water Surface ◽  
The Impact

Abstract Agricultural operations face increasing pressure to remediate runoff to reduce deterioration of surface water quality. Some nursery operations use free water surface constructed wetland systems (CWSs) to remediate nutrient-rich runoff. Our objectives were twofold, first to examine the impact of two hydraulic retention times (HRT, 3.5 and 5.5 day) on CWS performance, and second to determine if increased nutrient loading from internal CWS and nursery sources during the spring contributed to nutrient export in excess of regulatory limits. We quantified nutrient loading and removal efficiency in a free water surface CWS from late winter through late spring over three years and monitored various water quality parameters. Total nitrogen in runoff was reduced from 20.6 ± 2.8 mg·liter−1 (ppm) to 4.1 ± 1.3 mg·liter−1 (ppm) nitrogen after CWS treatment. Phosphorus dynamics in the CWS were more variable and unlike nitrogen dynamics were not consistently influenced by water temperature and hydraulic loading rate. Phosphorus concentrations were reduced from 1.7 ± 0.8 mg·liter−1 (ppm) PO4-P in influent to 1.2 ± 0.6 mg·liter−1 (ppm) PO4-P in CWS effluent, but substantial variability existed among years in both phosphorus loading and removal rates. The CWS was able to efficiently remediate nitrogen even under high spring loading rates.

scholarly journals Impact of fires on eutrophication in rivers (the Simmy River, the Bolon Nature Reserve)

2021 ◽  
Vol 895 (1) ◽  
pp. 012014
Author(s):  
G V Kharitonova ◽  
A V Ostrouhov ◽  
Z Tyugai ◽  
V O Krutikova
Keyword(s):  
Bottom Sediments ◽  
Nutrient Loading ◽  
Nature Reserve ◽  
Far East ◽  
Remote Sensing Data ◽  
River System ◽  
River Watershed ◽  
Phosphate Ions ◽  
East Russia ◽  
The Impact

Abstract Compared to research on eutrophication in lakes, our understanding of eutrophication in rivers remains extremely limited. This is especially true of the impact of fires, which have become much more frequent in recent decades. Since the risks of eutrophication in rivers as a result of fires increase, it is important to timely assess the impact of fires on the state of rivers draining fire-prone territories. The aim of the study is to select and evaluate the reliability of criteria for impact of fires on eutrophication in stream on the example of the Simmi River (Bolon Nature Reserve, Far East, Russia). The tasks of the work are to assess the fire-prone of the territory from remote sensing data and and to identify markers of the impact of fires on the Simmi River. The fire-prone of the river watershed was estimated by the fire repeatability. The in situ study dealt with river bottom sediments. The sampling was carried out in in three month and the third year after the fire. To assess the impact of fires on eutrophication in the Simmi River, we used the P content in bottom sediments as a marker of the nutrient loading. The obtained results indicate high fire-prone and repeatability of fires the river watershed. In the first months after the fire, the response of the river system is the sequestration of P soluble compounds as a result of the binding of phosphate ions to vivianite. Vivianite is formed on the surface of clay microaggregates, which are removed by the stream over time. In three years after fire, vivianite-clay microaggregates were not detected. Flushing in flow system tends to reduce the scale of the fire impact.

scholarly journals Modelling microbiological water quality in the Seine river drainage network: past, present and future situations

2007 ◽  
Vol 11 (5) ◽  
pp. 1581-1592 ◽  
Author(s):  
P. Servais ◽  
G. Billen ◽  
A. Goncalves ◽  
T. Garcia-Armisen
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Nutrient Loading ◽  
Large River ◽  
Population Increase ◽  
Wastewater Management ◽  
Drainage Network ◽  
Seine River ◽  
Microbiological Water Quality ◽  
The Impact

Abstract. The Seine river watershed is characterized by a high population density and intense agricultural activities. Data show low microbiological water quality in the main rivers (Seine, Marne, Oise) of the watershed. Today, there is an increasing pressure from different social groups to restore microbiological water quality in order to both increase the safety of drinking water production and to restore the possible use of these rivers for bathing and rowing activities, as they were in the past. A model, appended to the hydro-ecological SENEQUE/Riverstrahler model describing the functioning of large river systems, was developed to describe the dynamics of faecal coliforms (FC), the most usual faecal contamination indicator. The model is able to calculate the distribution of FC concentrations in the whole drainage network resulting from land use and wastewater management in the watershed. The model was validated by comparing calculated FC concentrations with available field data for some well-documented situations in different river stretches of the Seine drainage network. Once validated, the model was used to test various predictive scenarios, as, for example, the impact of the modifications in wastewater treatment planned at the 2012 horizon in the Seine watershed in the scope of the implementation of the european water framework directive. The model was also used to investigate past situations. In particular, the variations of the microbiological water quality in the Parisian area due to population increase and modifications in wastewater management were estimated over the last century. It was shown that the present standards for bathing and other aquatic recreational activities are not met in the large tributaries upstream from Paris since the middle of the 1950's, and at least since the middle of the XIXth century in the main branch of the Seine river downstream from Paris. Efforts carried out for improving urban wastewater treatment in terms or organic matter and nutrient loading resulted in a sensible reduction of microbiological contamination, but were not specific enough toward bacteriological contamination for achieving the objective of restoring levels compatible with bathing activities in the Parisian area.

scholarly journals Small Reservoir Impact on Simulated Watershed-Scale Nutrient Yield

2007 ◽  
Vol 2007 ◽  
pp. 1-4 ◽  
Author(s):  
Shane J. Prochnow ◽  
Joseph D. White ◽  
Thad Scott ◽  
Christopher Filstrup
Keyword(s):  
Total Phosphorus ◽  
Nutrient Loading ◽  
Assessment Tool ◽  
Agricultural Runoff ◽  
Surface Flow ◽  
Long Term Storage ◽  
Nutrient Yield ◽  
Potential Strategy ◽  
The Impact

The soil and water assessment tool (SWAT) is used to assess the influence of small upland reservoirs (PL566) on watershed nutrient yield. SWAT simulates the impact of collectively increasing and decreasing PL566 magnitudes (size parameters) on the watershed. Totally removing PL566 reservoirs results in a 100%increase in total phosphorus and an 82%increase in total nitrogen, while a total maximum daily load (TMDL) calling for a 50%reduction in total phosphorus can be achieved with a 500%increase in the magnitude of PL566s in the watershed. PL566 reservoirs capture agriculture pollution in surface flow, providing long-term storage of these constituents when they settle to the reservoir beds. A potential strategy to reduce future downstream nutrient loading is to enhance or construct new PL566 reservoirs in the upper basin to better capture agricultural runoff.

Aquaculture impacts on the algal and bacterial communities in a small boreal forest lakeThis paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 1936-1948 ◽  
Author(s):  
David L. Findlay ◽  
Cheryl L. Podemski ◽  
Susan E.M. Kasian
Keyword(s):  
Water Quality ◽  
Nutrient Loading ◽  
Stocking Density ◽  
Freshwater Ecosystem ◽  
Experimental Lakes Area ◽  
Fish Food ◽  
Total N ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Northwestern Ontario ◽  
The Impact

A whole-lake experiment to examine the impacts of aquaculture on a freshwater ecosystem was conducted at the Experimental Lakes Area in northwestern Ontario, Canada. From 2003 to 2006, a 10 tonne fish capacity aquaculture cage stocked with rainbow trout ( Oncorhynchus mykiss ) was operated in Lake 375 and the impact of excess nutrients on the algal and bacteria communities was examined. The experiment was designed as a nutrient loading experiment with fish food and fish excretion the source of nutrients. Total N and P concentrations increased over the 4 years (15× and 4×, respectively). Phytoplankton biomass increased 4× annually following the start of aquaculture operation in 2003. The most dramatic responses occurred during spring and fall mixing, with blooms of chrysophytes and dinoflagellates increasing biomass by up to 12×. Bacteria biomass and densities were unaffected except for increases in late fall. Periphyton biomass was relatively unaffected except for an increase in biomass in the fourth year. The combination of a long water residence time in the lake coupled with an extremely high fish stocking density in Lake 375 resulted in an immediate impact on water quality. The results suggest that the impacts of aquaculture are accumulative and continual stocking will further impact water quality.

Sign in / Sign up

Export Citation Format

Share Document