scholarly journals Stormwater management in nutrient-sensitive watersheds: a case study investigating impervious cover limits and pollutant-load regulations

2018 ◽  
Vol 78 (3) ◽  
pp. 664-675
Author(s):  
Charles C. Stillwell ◽  
William F. Hunt ◽  
Jonathan L. Page ◽  
Joshua B. Baird ◽  
Shawn G. Kennedy
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Stormwater Management ◽  
Management Strategies ◽  
Control Measures ◽  
Nutrient Export ◽  
Pollutant Load ◽  
Loading Rates ◽  
Impervious Cover

Abstract The objective of this research project was to compare two stormwater management strategies within a nutrient-sensitive watershed: impervious cover limits versus pollutant-load regulations. A case study was conducted in the nutrient-sensitive Falls Lake watershed in North Carolina, USA, where a commercial fitness complex was constructed in a zone previously restricted to low-density housing. The Falls Lake watershed has a stormwater regulation that limits total nitrogen and total phosphorus export loads to 2.47 kg/ha/yr and 0.37 kg/ha/yr, respectively. Hydrology and water quality were monitored pre- and post-development to quantify changes to stormwater volumes, pollutant concentrations, and annual export loading rates. On-site stormwater control measures (SCMs) reduced nutrient export loading rates below the regulatory standard. However, increased stormwater volumes and nutrient export loading rates were observed from pervious surfaces that were disturbed during construction (total nitrogen increased from 2.06 to 4.24 kg/ha/yr, total phosphorus increased from 0.41 to 0.73 kg/ha/yr). Results from this case study suggest that (1) impervious cover limits do not adequately account for a parcel's nutrient export loads and (2) SCMs that reduce volume and treat pollutants can reduce nutrient export loads below regulatory levels in the Falls Lake watershed.

Influence of climate change and human activity on total nitrogen and total phosphorus: a case study of Lake Taihu, China

2020 ◽  
Vol 36 (2) ◽  
pp. 186-202 ◽  
Author(s):  
Xiaojuan Xu ◽  
Huiyu Liu ◽  
Fusheng Jiao ◽  
Yujia Ren ◽  
Haibo Gong ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Lake Taihu

scholarly journals Management strategies for aflatoxin risk mitigation in maize, dairy feeds and milk value chains—case study Kenya

2021 ◽  
Vol 5 ◽  
Author(s):  
Vesa V Joutsjoki ◽  
Hannu J Korhonen
Keyword(s):  
Risk Mitigation ◽  
Global Climate ◽  
Management Strategies ◽  
Aflatoxin Contamination ◽  
Control Measures ◽  
Value Chains ◽  
Small Scale ◽  
African Countries ◽  
Food And Feed

Abstract Widespread aflatoxin contamination of a great number of food and feed crops has important implications on global trade and health. Frequent occurrence of aflatoxin in maize and milk poses serious health risks to consumers because these commodities are staple foods in many African countries. This situation calls for development and implementation of rigorous aflatoxin control measures that encompass all value chains, focusing on farms where food and feed-based commodities prone to aflatoxin contamination are cultivated. Good agricultural practices (GAP) have proven to be an effective technology in mitigation and management of the aflatoxin risk under farm conditions. The prevailing global climate change is shown to increase aflatoxin risk in tropical and subtropical regions. Thus, there is an urgent need to devise and apply novel methods to complement GAP and mitigate aflatoxin contamination in the feed, maize and milk value chains. Also, creation of awareness on aflatoxin management through training of farmers and other stakeholders and enforcement of regular surveillance of aflatoxin in food and feed chains are recommended strategies. This literature review addresses the current situation of aflatoxin occurrence in maize, dairy feeds and milk produced and traded in Kenya and current technologies applied to aflatoxin management at the farm level. Finally, a case study in Kenya on successful application of GAP for mitigation of aflatoxin risk at small-scale farms will be reviewed.

A Strategy for Estimating Nutrient Concentrations Using Remote Sensing Datasets and Hydrological Modeling

2012 ◽  
Vol 3 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Vladimir J. Alarcon ◽  
William H. McAnally
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Hydrological Modeling ◽  
Northern Region ◽  
Nutrient Concentrations ◽  
Nutrient Export

This paper presents a methodology for estimating nutrient concentrations of total phosphorus (TP) and total nitrogen (TN) through the use of hydrological modeling, remote sensing datasets, and nutrient export coefficients. The strategy is applied to the Upper Tombigbee watershed, located in the northern region of the states of Mississippi and Alabama, USA. USGS GIRAS (1986), NASA MODIS MOD12Q1 (2001-2004) land use datasets, and USGS-DEM topographical datasets were used to characterize the physiography of the watershed. TN and TP concentration values estimated using the methodology were compared to values reported in the literature.

A Case Study of Pollutant Load Trading on the Truckee River

2001 ◽  
Author(s):  
Steve McDonald ◽  
Seema Bhimani ◽  
Greg Dennis ◽  
Randall Gray ◽  
Steve Walker
Keyword(s):  
Truckee River ◽  
Pollutant Load

Effect of Financial Control Mechanisms on Performance of Income Generating Units in Selected Public Universities in Kenya

2019 ◽  
Vol 3 (V) ◽  
pp. 286-304
Author(s):  
Shadrack Musunkui Towett ◽  
Isaac Naibei ◽  
Williter Rop
Keyword(s):  
Risk Management ◽  
Internal Control ◽  
Public Universities ◽  
Management Strategies ◽  
Internal Audit ◽  
Simple Random Sampling ◽  
Target Population ◽  
Control Measures ◽  
Financial Control ◽  
Control Mechanisms

In an attempt to bridge the gap between the budgetary allocations and actual expenditures most universities have started income generating units with the aim of boosting their operational expenses. Whereas there is the potential of the use of Income Generating Units (IGUs) to generate additional funds, most universities still experience challenges in full implementation and realization of the revenue goal. This study therefore sought to determine the financial control mechanisms affecting performance of income generating units among selected public universities. The study sought to determine the effect of internal controls, credit policies, financial risk management and internal audit on performance of income generating units in selected universities. Targeted population was all the 290 employees in the IGU departments of selected public universities. The respondents were sampled using simple random sampling so as to enable equal representation of the target population without any biasness. Data collection was done using the questionnaire to ensure sufficient data was collected from the respondents. Descriptive statistics assisted in the determination of respondent’s views and opinions on every variable. Qualitative data was analysed using content analysis into meaningful, precise and comprehensive statements and presented in quotations. Data analysis was done using SPSS version 21 and data presented in form of figures and tables. The study ensured that all ethical considerations were considered by the study. The findings were that most employed Income Generating Units in Public Universities were Collection of rental fees, Evening and executive programs and Trainings of both short and long courses while the least was established to be Sales of memorabilia and books. All the financial control mechanism investigated namely internal audit, internal control measures, risk management strategies and credit policies had large extents of adoption in the selected universities. The results of the regression analysis showed that the financial control mechanisms investigated had a significant positive relationship on performance of the IGUs. Specifically, 47% of the variation of the performance of IGUs was established to be explained by the studied factors. The study concluded that the performance of the IGUs among the selected public universities was largely accounted for by the implemented financial control measures. Therefore effective financial control mechanisms is concluded to lead to better IGU performance whereas shortcomings in the financial control mechanisms is concluded to lead to diminished returns in the IGUs. The study recommended that the management in charge of the IGU department in the public universities to prioritize the formulation, implementation and monitoring of financial control mechanisms in the IGUs. To facilitate effective financial controls, the study recommended that the management especially those in the audit section to conduct regular checks and inspections on the IGUs. Additionally, frequent reforms were recommended to address the shortcomings experienced in integrating financial control measures in IGUs.

IPM—A Problem-based Learning Approach

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509e-509
Author(s):  
Robert P. Rice
Keyword(s):  
Pest Control ◽  
Test Performance ◽  
Management Strategies ◽  
Ornamental Plants ◽  
Real Life ◽  
Problem Based Learning ◽  
Control Measures ◽  
Learning Approach ◽  
Pest Monitoring ◽  
Use Of Resources

The Cal Poly philosophy of “Learn and Understand by Doing” has been integrated with problem-based learning and the use of the latest technology to produce a class that closely simulates real-life pest control situations. Goals of the class, Disease and Pest Control Systems for Ornamental Plants, are to teach students pest monitoring, control and problem solving techniques, the use of resources including the internet and journals, and the use of the latest pest control equipment and application techniques. Students are shown pest situations and then work in groups to diagnose the problem, investigate management strategies, apply control measures, and monitor results. Weekly class presentations inform the class of the various projects and help to teach the class organization and presentation skills. Student evaluations and test performance have demonstrated that students achieve class objectives substantially better with the problem-based learning approach than with the previous lecture-based approach to the class.

Danish Experience with Emergent Hydrophyte Treatment Systems (EHTS) and Prospects in the Light of Future Requirements on Outlet Water Quality

1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix
Keyword(s):  
Wastewater Treatment ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Reed Beds ◽  
Effluent Quality ◽  
Multi Stage ◽  
Run Off ◽  
Stage System

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

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