Agricultural Nitrogen and Phosphorus Pollution in Surface Waters

2019 ◽  
Author(s):  
Marianne Bechmann ◽  
Per Stålnacke
Keyword(s):  
Surface Waters ◽  
Algal Blooms ◽  
Negative Impact ◽  
Spatial Scales ◽  
Mitigation Measures ◽  
Nutrient Pollution ◽  
Nutrient Loads ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Pollution ◽  
Basin Scale

Nutrient pollution can have a negative impact on the aquatic environment, with loss of biodiversity, toxic algal blooms, and a deficiency in dissolved oxygen in surface waters. Agricultural production is one of the main contributors to these problems; this article provides an overview of and background for the main biogeochemical processes causing agricultural nutrient pollution of surface waters. It discusses the main features of the agricultural impact on nutrient loads to surface waters, focusing on nitrogen and phosphorus, and describes some of the main characteristics of agricultural management, including processes and pathways from soil to surface waters. An overview of mitigation measures to reduce pollution, retention in the landscape, and challenges regarding quantification of nutrient losses are also dealt with. Examples are presented from different spatial scales, from field and catchment to river basin scale.

scholarly journals Source Apportionment of Nutrient Loads to a Mediterranean River and Potential Mitigation Measures

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 577 ◽  
Author(s):  
Anna Maria De Girolamo ◽  
Antonio Lo Porto
Keyword(s):  
Water Quality ◽  
Low Flow ◽  
Treated Wastewater ◽  
Mitigation Measures ◽  
Organic N ◽  
N Fixation ◽  
Nutrient Loads ◽  
Total Load ◽  
Total Input ◽  
Basin Scale

The aims of the study were to quantify nutrient loads from point and diffuse pollution sources in the Rio Mannu stream and to simulate mitigation measures for reducing nutrient loads delivered to the Santa Gilla wetland. The Soil and Water Assessment Tool model was used for simulating hydrology, nutrient balance and water quality. At the basin scale, the input from fertilisers was 80.3 kg ha−1 year−1 total nitrogen (TN) (87.6% of the total input) and 27.6 kg ha−1 year−1 of total phosphorus (TP) (99.8% of the total input). Atmospheric deposition and biological N-fixation together accounted for about 12% of the total TN input. The TN and TP from wastewater treatment plants (WWTPs) were about 14.2 t year−1 and 3.1 t year−1, respectively. Nutrient loads delivered to the river system differed among the sub-basins, with TP ranging from 0.2 kg ha−1 year−1 to 2.7 kg ha−1 year−1, and the sum of organic N and NO3-N ranging from 1.8 kg ha−1 year−1 to 22.9 kg ha−1 year−1. Under high flow conditions, NO3-N and TP accounted for 89% and 99% of the total load, respectively. The low flow contribution to the total load was very low, with NO3-N and TP accounting for 2.8% and 0.7%, respectively. However, the natural hydrological regime in the study area is intermittent, and low flow represents a critical condition for the water quality due to the high concentrations of TP and NO3-N from WWTP discharge. To improve the water quality, the reuse of treated wastewater from three WWTPs for irrigation purposes on olive cultivation, coupled with a 20% reduction in fertiliser application, was simulated. The results showed a reduction in nutrient loads at the outlet for all hydrological conditions. However, additional measures are needed for improving water quality.

The influence of drained peat soils on diffuse nitrogen pollution of surface water

2012 ◽  
Vol 43 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Anatoli Vassiljev ◽  
Irina Blinova
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
Nitrogen Pollution ◽  
Mineral Fertilizers ◽  
Nutrient Loads ◽  
Agricultural Lands ◽  
Nitrogen And Phosphorus ◽  
Peat Soils ◽  
Nitrogen Export ◽  
Drastic Decrease

Eutrophication caused by excess nutrient loads is the main problem for Estonian surface waters. Even after the drastic decrease in the application of mineral fertilizers at the beginning of the 1990s, the concentrations of nitrogen and phosphorus in many rivers remained at undesirable and unexpectedly high levels. The investigation showed that drained peat soils are an important source of nitrogen export to the surface waters. Runoff of nitrogen from drained peat soils is, on average, 1.5-fold higher than from agricultural lands in Estonia.

scholarly journals Improving the agricultural erosion management in Finland through high-resolution data

2021 ◽  
Author(s):  
Timo A. Räsänen ◽  
Mika Tähtikarhu ◽  
Jaana Uusi-Kämppä ◽  
Sirpa Piirainen ◽  
Eila Turtola
Keyword(s):  
High Resolution ◽  
Soil Erosion ◽  
Surface Waters ◽  
Management Practices ◽  
Agricultural Land ◽  
Spatial Scales ◽  
Mitigation Measures ◽  
High Resolution Data ◽  
Erosion Risk ◽  
Resolution Data

Abstract. Soil erosion reduces the sustainability of agricultural sector by loss of productive soil and through negative impacts on surface waters. In Finland, considerable efforts have been made to reduce soil erosion, but the suspended sediment loads to surface waters have not markedly reduced. A major limitation has been the lack of high-resolution data on erosion risk for efficient targeting of the erosion management efforts. In this study, by using the Revised Universal Soil Loss Equation (RUSLE) a two-meter resolution erosion risk data was developed and consequently the spatial distribution of the erosion risk of Finnish agricultural land was analysed. With agricultural management practices of 2019, the average erosion of agricultural land was estimated to be 430 kg ha−1 yr−1, and it varied at the municipality scale from 100 to 1290 kg ha−1 yr−1. At more local scales the erosion risk had even greater variability, and areas with high erosion risk were differently located in terms distances to water bodies. The results also suggest that the past erosion management efforts have not been well-targeted according to the actual erosion risk. Altogether, the results indicate that erosion mitigation measures can be improved by inclusion of high-resolution data in the planning and implementation of the measures, by considering the spatial variability of the erosion risk over multiple spatial scales, and by implementation of location specific erosion reduction measures.

Water Quality Trends in Hamilton Harbour: 1987 to 1995

1996 ◽  
Vol 31 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Murray N. Charlton ◽  
Robin Le Sage
Keyword(s):  
Algal Blooms ◽  
Action Plan ◽  
Secchi Depth ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Hamilton Harbour ◽  
Near Shore ◽  
The Media ◽  
Park Area ◽  
Water Quality Trends

Abstract A series of water samples and Secchi depth measurements were conducted in Hamilton Harbour between 1987 and 1995. The data indicate little recent improvement in the harbour generally. Detection of real improvements may require high frequency sampling and a more extensive sample grid once a cause for improvement is in place. Some measures, such as chlorophyll and Secchi depth, approach RAP initial goals sometimes during recent years, but algal blooms still occur, which prevent attainment of satisfactory average conditions. The cause of aesthetic improvements in water clarity reported in the media was investigated with sampling along an inshore-offshore transect and intense Secchi measurements in the LaSalle Park area. The data are consistent with a transient clarifying effect of zebra mussels on structures near shore. The need to reduce nutrient loads as recommended in the Remedial Action Plan continues.

scholarly journals Performance of a Handheld Chlorophyll-a Fluorometer: Potential Use for Rapid Algae Monitoring

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1409
Author(s):  
Hamdhani Hamdhani ◽  
Drew E. Eppehimer ◽  
David Walker ◽  
Michael T. Bogan
Keyword(s):  
Chlorophyll A ◽  
Surface Waters ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Water Quality Monitoring ◽  
Ambient Light ◽  
Calibration Equation ◽  
Field Samples ◽  
Potential Use

Chlorophyll-a measurements are an important factor in the water quality monitoring of surface waters, especially for determining the trophic status and ecosystem management. However, a collection of field samples for extractive analysis in a laboratory may not fully represent the field conditions. Handheld fluorometers that can measure chlorophyll-a in situ are available, but their performance in waters with a variety of potential light-interfering substances has not yet been tested. We tested a handheld fluorometer for sensitivity to ambient light and turbidity and compared these findings with EPA Method 445.0 using water samples obtained from two urban lakes in Tucson, Arizona, USA. Our results suggested that the probe was not sensitive to ambient light and performed well at low chlorophyll-a concentrations (<25 µg/L) across a range of turbidity levels (50–70 NTU). However, the performance was lower when the chlorophyll-a concentrations were >25 µg/L and turbidity levels were <50 NTU. To account for this discrepancy, we developed a calibration equation to use for this handheld fluorometer when field monitoring for potential harmful algal blooms in water bodies.

scholarly journals Phosphorous runoff risk assessment and its potential management using wollastonite according to geochemical modeling

2019 ◽  
Vol 4 (1) ◽  
pp. 787-794 ◽  
Author(s):  
Aneela Hayder ◽  
Stephen Vanderburgt ◽  
Rafael M. Santos ◽  
Yi Wai Chiang
Keyword(s):  
Risk Analysis ◽  
Algal Blooms ◽  
Agricultural Land ◽  
Algal Bloom ◽  
Risk Mitigation ◽  
Geochemical Modeling ◽  
Geochemical Modelling ◽  
Water Runoff ◽  
Phosphorus Pollution ◽  
Contaminate Drinking Water

AbstractLoss of phosphorus from agricultural land through water runoff causes serious detrimental effects on the environment and on water quality. Phosphorous runoff from excessive use of fertilizers can cause algal blooms to grow in nearby water systems, producing toxins that contaminate drinking water sources and recreational water. In this study, a risk analysis of the algal toxin micro-cystin-LR and the mitigation of phosphorus from agriculture runoff is discussed. A risk analysis was performed on the algal bloom toxin microcystin-LR considering the Lake Erie algal bloom event of 2011 as a case study. Toxicity risk analysis results show that relatively low concentrations of microcystin-LR compared to recent case studies pose an acute health risk to both children and adults, and a significant increase in the risk of developing cancer is suggested but subject to further study given the assumptions made. This study investigated the potential of using wollastonite to mitigate phosphorus pollution, considering thermodynamic conditions of a constructed wetland receiving influent water from agriculture runoff, by using geochemical modelling. Geochemical modelling results show that wollastonite can react with phosphorus and capture it in the stable mineral form of hydroxyapatite, offering a possible strategy for risk mitigation of phosphorous runoff. A removal efficiency of 77% of phosphorus using wollastonite is calculated with the help of geochemical modelling.

scholarly journals A Review of SWAT Model Application in Africa

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1313
Author(s):  
George Akoko ◽  
Tu Hoang Le ◽  
Takashi Gomi ◽  
Tasuku Kato
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Hydrological Modeling ◽  
Assessment Tool ◽  
Swat Model ◽  
Data Availability ◽  
Mitigation Measures ◽  
Model Parameterization ◽  
Basin Scale

The soil and water assessment tool (SWAT) is a well-known hydrological modeling tool that has been applied in various hydrologic and environmental simulations. A total of 206 studies over a 15-year period (2005–2019) were identified from various peer-reviewed scientific journals listed on the SWAT website database, which is supported by the Centre for Agricultural and Rural Development (CARD). These studies were categorized into five areas, namely applications considering: water resources and streamflow, erosion and sedimentation, land-use management and agricultural-related contexts, climate-change contexts, and model parameterization and dataset inputs. Water resources studies were applied to understand hydrological processes and responses in various river basins. Land-use and agriculture-related context studies mainly analyzed impacts and mitigation measures on the environment and provided insights into better environmental management. Erosion and sedimentation studies using the SWAT model were done to quantify sediment yield and evaluate soil conservation measures. Climate-change context studies mainly demonstrated streamflow sensitivity to weather changes. The model parameterization studies highlighted parameter selection in streamflow analysis, model improvements, and basin scale calibrations. Dataset inputs mainly compared simulations with rain-gauge and global rainfall data sources. The challenges and advantages of the SWAT model’s applications, which range from data availability and prediction uncertainties to the model’s capability in various applications, are highlighted. Discussions on considerations for future simulations such as data sharing, and potential for better future analysis are also highlighted. Increased efforts in local data availability and a multidimensional approach in future simulations are recommended.

scholarly journals A cost-effectiveness analysis of water security and water quality: impacts of climate and land-use change on the River Thames system

2013 ◽  
Vol 371 (2002) ◽  
pp. 20120413 ◽  
Author(s):  
P. G. Whitehead ◽  
J. Crossman ◽  
B. B. Balana ◽  
M. N. Futter ◽  
S. Comber ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Cost Effectiveness ◽  
Land Use Change ◽  
Algal Blooms ◽  
Economic Benefits ◽  
Point Sources ◽  
Mitigation Measures ◽  
Mitigation And Adaptation ◽  
River Thames

The catchment of the River Thames, the principal river system in southern England, provides the main water supply for London but is highly vulnerable to changes in climate, land use and population. The river is eutrophic with significant algal blooms with phosphorus assumed to be the primary chemical indicator of ecosystem health. In the Thames Basin, phosphorus is available from point sources such as wastewater treatment plants and from diffuse sources such as agriculture. In order to predict vulnerability to future change, the integrated catchments model for phosphorus (INCA-P) has been applied to the river basin and used to assess the cost-effectiveness of a range of mitigation and adaptation strategies. It is shown that scenarios of future climate and land-use change will exacerbate the water quality problems, but a range of mitigation measures can improve the situation. A cost-effectiveness study has been undertaken to compare the economic benefits of each mitigation measure and to assess the phosphorus reductions achieved. The most effective strategy is to reduce fertilizer use by 20% together with the treatment of effluent to a high standard. Such measures will reduce the instream phosphorus concentrations to close to the EU Water Framework Directive target for the Thames.

GEOPHYSICAL MONITORING: NEW OPPORTUNITIES TO PRESERVE ARCHITECTURAL MONUMENTS AND GREEN DESIGN IN URBAN AREAS

2020 ◽  
Author(s):  
Zakhar Slepak
Keyword(s):  
Urban Areas ◽  
Negative Impact ◽  
Technical Condition ◽  
Green Design ◽  
World Heritage Site ◽  
Mitigation Measures ◽  
Operating Life ◽  
Geophysical Monitoring ◽  
Railway Systems ◽  
Geological Processes

A new geophysical prospecting technique developed by the author was effectively applied for these purposes in 1994–2005 within the architectural complex of the Kazan Kremlin, a UNESCO World Heritage Site. The author has developed and successfully employed a unique gravity monitoring technique consisting in independent measurements at set points and at certain time intervals in the architectural complex of the Kazan Kremlin. The results of the geophysical monitoring and geodetic surveys conducted in open areas and inside architectural monuments offer new opportunities in preserving ancient buildings. Because geophysical monitoring can identify the negative impact of active geological processes on foundations of buildings, mitigation measures can be taken in timely manner. However, because the Kazan Kremlin is a state historical and architectural museum reserve, another objective is to maintain its exterior and renovate its green design. The above technology can also be used to analyze the technical condition of high-rise buildings, industrial facilities, underground railway systems and other structures, and significantly prolong their operating life.

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