scholarly journals Catchment Modelling Of Non – Point Source Pollution Accretion For Rivers

2016 ◽  
Vol 12 (2) ◽  
pp. 309
Author(s):  
O. E. Ekenta

Catchment process simulation models are designed to model the interaction of hydrological, geochemical and ecological processes and the effects of change. TOMCAT, a catchment scale model was applied in modeling the transport of determinands from non-point (diffuse) sources to Mimram river, a tributary of the river Thames. The magnitude and timing of the processes taking place is stochastic with the model representing as accurately as possible the systematic and random variability of various model inputs and their inter-relationships. The results indicate that the BOD, NH4N and Un-ionised NH3 loads which enter the rivers from non-point sources increased by 0.55mg/l, 0.024mg/l and 0.001mg/l respectively. These values are relatively small. The Dissolved Oxygen concentration along the reach increased by 2.5 mg/l indicating substantial re-aeration along the reach. The accretion value for the conservative determinand Chloride was 3.75mg/l. Non-point source pollutants accretion to the Mimram is influenced by agricultural and silvicultural practices in the catchment. The results of the investigation indicate that the model could be adopted by environmental pollution control agencies as a management tool for intervention in the area of pollution abatement for catchments.

1994 ◽  
Vol 29 (3) ◽  
pp. 95-106
Author(s):  
Alfred P. Benoist ◽  
Gerard H. Broseliske

For priority pollutants, the international Rhine Action Programme (RAP) aims to meet the quality objectives for the Rhine, set by the International Rhine Commission (IRC), by the year 2000. An assessment must be carried out to define additional measures exceeding best available technology (BAT) for point sources and best environmental practice (BEP) for diffuse sources for those priority pollutants still violating the quality objectives of the Rhine after implementing BAT and BEP only. To carry out the required assessments, an excessive amount of work and money is needed, including the application of sophisticated calculation models. For prioritizing reasons, the Institute for Inland Water Management and Waste Water Treatment (RIZA) initiated a project called EVER, which was conducted by DHV Water BV. EVER is the abbreviation of the Dutch equivalent for Effective Distribution of Emission Reductions (Effective Verdeling van Emissie Reducties). The aim of this project is to carry out a first and crude evaluation of the impact of abatement measures (BAT and BEP), as set by the IRC for the period 1985-1995. For those pollutants still showing a violation of the quality objectives for the Rhine in the year 1995, a range finding method is used, to predict the costs and impact of abatement measures exceeding BAT and BEP on the water quality of the Rhine. So, EVER is a management tool to prioritize the work to be done within the frame-work of the IRC, triggering the application of e.g. sophisticated calculation models for a selected number of priority pollutants. In EVER, the prognosis of the reduction of specific discharge rates for approximately forty priority pollutants is given for twelve sub-catchment areas for the year 1995. This prognosis is used to predict concentrations at eight international monitoring locations in the Rhine basin, using the discharges and concentrations of the year 1985 as a reference. The predicted concentrations for the year 1995 are compared with the (preliminary) water quality objectives as set by the IRC. The results indicate, that for six of the selected pollutants the number of available data is too small for sound predictions. Fifteen of the selected pollutants will satisfy the water quality objectives in 1995. Twenty (half) of the selected pollutants will still violate the quality objectives at several monitoring locations. These twenty pollutants are the basis for priorities to be set within the frame-work of the IRC for phase 3 (1995-2000) of the RAP. For these pollutants, additional abatement measures exceeding BAT and BEP are selected in EVER for the manageable groups of sources (anthropogenic non-point sources, industrial sources and municipal sources). Each measure is analyzed separately for costs and effectiveness. Finally the results of this project are integrated into a matrix system which will enable us to select the most effective mix of pollution abatement measures at the lowest costs. The result of the selected additional measures exceeding BAT and BEP shows that 17 pollutants will still violate the quality objectives.


2019 ◽  
Author(s):  
◽  
Seungyub Lee

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Water pollution caused by nutrients, and the resulting eutrophication, have increased over time. This water pollution is increasingly caused by non-point source pollution, both nutrients and erosion. Controlling non-point pollution is important for water quality. However, non-point source pollution is not easy to track and control. In this case, management efforts can be solutions for these environmental issues in both urban and agricultural areas. In this dissertation, I focus on phosphorous (P) fertilizer because P is the limiting nutrient in freshwater systems. If we can reduce P runoff from urban and agricultural non-point sources, water quality can be improved. ... By analyzing national water quality and political economy data and by investigating a national survey of soybean producers, this dissertation found implications to increase adoption of environmentally friendly policies and practices. Solving this problem will require efforts to limit both residential and agricultural nonpoint source pollution. The results could be helpful policy makers to target specific regions to initiate environmental policies and extension efforts for designing educational programs to increase adoption rate as well as environmental quality.


2019 ◽  
Vol 19 (12) ◽  
pp. 2767-2779 ◽  
Author(s):  
Gyumin Lee ◽  
Kyung Soo Jun ◽  
Minji Kang

Abstract. This study aimed to develop a risk-based approach for determining control areas to manage non-point source pollution, developing a framework to prioritize catchments by considering the characteristics of polluted runoff from non-point sources. The best management, decision-making, and scientific approaches, such as the technique for order of preference by similarity to ideal solution (TOPSIS) and the Delphi technique, are required for the designation of control areas and the application of the best management practices to the control areas. Multi-criteria decision-making (MCDM) methods can handle the diversity and complexity of non-point source pollution. The Delphi technique was employed for selecting the assessment criteria/sub-criteria and determining their weights. Sub-criteria for each catchment unit were scored with either a quantitative or qualitative scale. All non-point pollution sources in mainland Republic of Korea were included, with the exception of a few islands, with catchment prioritization and pollution vulnerability evaluations shown as thematic maps. This study contributes to the field by developing a new risk-based approach for ranking and prioritizing catchments; this provides valuable information for the Ministry of Environment to use to identify control areas and manage non-point source pollution.


2003 ◽  
Vol 19 (2) ◽  
Author(s):  
K. C. Stone ◽  
P. G. Hunt ◽  
J. M. Novak ◽  
M. H. Johnson

2005 ◽  
Vol 20 (29) ◽  
pp. 6765-6768
Author(s):  
A. CHILINGARIAN ◽  
G. GHARAGYOZYAN ◽  
G. HOVSEPYAN ◽  
G. KARAPETYAN

The estimation of the significance of the peaks in 1 and 2-dimensional distributions is one of the most important problems in high-energy physics and astrophysics. The physical inference from low-statistics experiments usually is biased and many discoveries lack further confirmation. We analyze the significance of the experimental evidence in the on-going efforts of detecting the point source of Cosmic Rays. The analysis is carried out in the framework of two models utilizing the extremum statistics: first – using the fixed grid of celestial coordinates, and second – using the tuned grid (introducing more degrees of freedom in the search). The test distributions for the significance estimation are obtained both from simulation models and from the analytical treatment of the problem.


2013 ◽  
Vol 10 (11) ◽  
pp. 14463-14493
Author(s):  
B. B. Huang ◽  
D. H. Yan ◽  
H. Wang ◽  
B. F. Cheng ◽  
X. H. Cui

Abstract. Under the background of climate change and human's activities, there has been presenting an increase both in the frequency of droughts and the range of their impacts. Droughts may give rise to a series of resources, environmental and ecological effects, i.e. water shortage, water quality deterioration as well as the decrease in the diversity of aquatic organisms. This paper, above all, identifies the impact mechanism of drought on the surface water quality of the basin, and then systematically studies the laws of generation, transfer, transformation and degradation of pollutants during the drought, finding out that the alternating droughts and floods stage is the critical period during which the surface water quality is affected. Secondly, through employing indoor orthogonality experiments, serving drought degree, rainfall intensity and rainfall duration as the main elements and designing various scenario models, the study inspects the effects of various factors on the nitrogen loss in soil as well as the loss of non-point sources pollution and the leaching rate of nitrogen under the different alternating scenarios of drought and flood. It comes to the conclusion that the various factors and the loss of non-point source pollution are positively correlated, and under the alternating scenarios of drought and flood, there is an exacerbation in the loss of ammonium nitrogen and nitrate nitrogen in soil, which generates the transfer and transformation mechanisms of non-point source pollution from a micro level. Finally, by employing the data of Nenjiang river basin, the paper assesses the impacts of drought on the surface water quality from a macro level.


2006 ◽  
Vol 510-511 ◽  
pp. 606-609 ◽  
Author(s):  
Seog Ku Kim ◽  
Sang Leen Yun ◽  
Young Im Kim ◽  
Sung Won Kang ◽  
Yong Jae Lee

While more attention has been paid in recent years to urban point source pollution control, no considerable measures have been taken to control urban non-point source pollution. Contaminants from non-point sources deposited on urban impermeable surfaces such as road and highway are easily released to the public waters by rainfall, leading to the deterioration in water quality in urban area. Experiments were performed using a reactor and real rainwater runoff obtained from road surfaces at various pollutant loading and rainfall intensity to determine the criteria for the first flush rainwater and to evaluate the applicability of the reactor for treating road runoff. The results at different rainfall intensities show that the medium PPB is superior to the other media for water permeability. PPB was not blocked at 10 mm/hr rainfall, and its permeability was stable. On the other hand, PVS and PPF resulted in a substantial overflow ratio even at 1 mm/hr rainfall intensity. Comparison of treatment efficiencies for suspended solids showed that all media showed similar removal efficiency ranging from 91% to 95%. However, PPB seems to be better than the other media considering its higher water permeability. PPB and PPF, both hydrophobic, yielded over 76% of heavy metal removal. But the hydrophilic media PVS showed much smaller removal efficiency ranging from 26% to 47%. The treatment efficiencies over PAHs (Poly Aromatic Hydrocarbons) showed the similar removal efficiency ranging from 66% to 97% for all three media. In this study a reactor using filter media was investigated to reduce the level of contamination in urban road runoff.


Author(s):  
Qian Li ◽  
Zhonghua Yang ◽  
Yao Yue ◽  
Hua Zhong ◽  
Da Li

Abstract Excessive phosphorus has become the primary reason for the deterioration of the water quality of the upper Yangtze River Basin. Here, we comprehensively study variations in total phosphorus (TP) concentration and TP loads in the upper reach of the Yangtze River during 2004–2017 (after the impoundment of the Three Gorges Dam). Non-point source TP loads flowing into the mainstream are also analyzed based on the base flow segmentation method. TP concentration in the mainstream showed a fluctuating trend of decreasing–increasing–decreasing from 2004 to 2017. TP loads from tributaries had a greater impact on TP concentration in the mainstream than the retention effect. Non-point source was an important source of TP loads. Average TP loads from non-point source pollution were 24.9 × 106 kg per year, contributing about 50.8% of the TP loads from 2004 to 2017. Non-point source TP loads were mainly from Jinsha River and Jialing River, accounting for 59.1% of total non-point TP loads, and they mainly occurred in the wet season. The long-term variation trend of TP loads from tributaries was affected by economic development, intensity of pollution control and significant discharge change. In terms of pollution control, we suggest comprehensive treatment of point and non-point source pollution.


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