thesis on water analysis

• Skip to main content
• Accessibility information

• Enlighten Enlighten

Enlighten Theses

• Latest Additions
• Browse by Year
• Browse by Subject
• Browse by College/School
• Browse by Author
• Browse by Funder
• Login (Library staff only)

In this section

Evaluation of sampling and monitoring designs for water quality

Haggarty, Ruth Alison (2012) Evaluation of sampling and monitoring designs for water quality. PhD thesis, University of Glasgow.

Assessing water quality is of crucial importance to both society and the environment. Deterioration in water quality through issues such as eutrophication presents substantial risk to human health, plant and animal life, and can have detrimental effects on the local economy. Long-term data records across multiple sites can be used to investigate water quality and risk factors statistically, however, identification of underlying changes can only be successful if there is a sufficient quantity of data available. As vast amounts of resources are required for the implementation and maintenance of a monitoring network, logistically and financially it is not possible to employ continuous monitoring of all water environments. This raises the question as to the optimal design for long-term monitoring networks which are capable of capturing underlying changes. Two of the main design considerations are clearly where to sample, and how frequently to sample. The principal aim of this thesis is to use statistical analysis to investigate frequently used environmental monitoring networks, developing new methodology where appropriate, so that the design and implementation of future networks can be made as effective and cost efficient as possible. Using data which have been provided by the Scottish Environment Protection Agency, several data from Scottish lakes and rivers and a range of determinands are considered in order to explore water quality monitoring in Scotland. Chapter 1 provides an introduction to environmental monitoring and both existing statistical techniques, and potential challenges which are commonly encountered in the analysis of environmental data are discussed. Following this, Chapter 2 presents a simulation study which has been designed and implemented in order to evaluate the nature and statistical power for commonly used environmental sampling and monitoring designs for surface waters. The aim is to answer questions regarding how many samples to base the chemical classification of standing waters, and how appropriate the currently available data in Scotland are for detecting trends and seasonality. The simulation study was constructed to investigate the ability to detect the different underlying features of the data under several different sampling conditions. After the assessment of how often sampling is required to detect change, the remainder of the thesis will attempt to address some of the questions associated with where the optimal sampling locations are. The European Union Water Framework Directive (WFD) was introduced in 2003 to set compliance standards for all water bodies across Europe, with an aim to prevent deterioration, and ensure all sites reach `good' status by 2015. One of the features of the WFD is that water bodies can be grouped together and the classification of all members of the group is then based on the classification of a single representative site. The potential misclassification of sites means one of the key areas of interest is how well the existing groups used by SEPA for classification capture differences between the sites in terms of several chemical determinands. This will be explored in Chapter 3 where a functional data analysis approach will be taken in order to investigate some of the features of the existing groupings. An investigation of the effect of temporal autocorrelation on our ability to distinguish groups of sites from one another will also be presented here. It is also of interest to explore whether fewer, or indeed more groups would be optimal in order to accurately represent the trends and variability in the water quality parameters. Different statistical approaches for grouping standing waters will be presented in Chapter 4, where the question of how many groups is statistically optimal is also addressed. As in Chapter 3, these approaches for grouping sites will be based on functional data in order to include the temporal dynamics of the variable of interest within any analysis of group structure obtained. Both hierarchical and model based functional clustering are considered here. The idea of functional clustering is also extended to the multivariate setting, thus enabling information from several determinands of interest to be used within formation of groups. This is something which is of particular importance in view of the fact that the WFD classification encompasses a range of different determinands. In addition to the investigation of standing waters, an entirely different type of water quality monitoring network is considered in Chapter 5. While standing waters are assumed to be spatially independent of one another there are several situations where this assumption is not appropriate and where spatial correlation between locations needs to be accounted for. Further developments of the functional clustering methods explored in Chapter 4 are presented here in order to obtain groups of stations that are not only similar in terms of mean levels and temporal patterns of the determinand of interest, but which are also spatially homogenous. The river network data explored in Chapter 5 introduces a set of new challenges when considering functional clustering that go beyond the inclusion of Euclidean distance based spatial correlation. Existing methodology for estimating spatial correlation are combined with functional clustering approaches and developed to be suitable for application on sites which lie along a river network. The final chapter of this thesis provides a summary of the work presented and discussion of limitations and suggestions for future directions.

Actions (login required)

Downloads per month over past year

View more statistics

The University of Glasgow is a registered Scottish charity: Registration Number SC004401

• Water Science
• Agricultural Science
• Drinking Water

BACTERIOLOGICAL ANALYSIS OF DRINKING WATER

• Conference: BIOSYM-2013
• This person is not on ResearchGate, or hasn't claimed this research yet.

• MLSU university udaippur

• Indira Gandhi National Open University (IGNOU)

Abstract and Figures

Discover the world's research

• 25+ million members
• 160+ million publication pages
• 2.3+ billion citations
• Joan Danquah

• Solomon Boachie
• Benson Kwabena Owusu
• Darin El-Bolok

• Syed Tasleem Hussain

• Sompal Singh

• Madhav Prasad Baral
• D.H. Tambekar

• Bhokare D.D

• Roland Persaud
• John Caesar

• AFR J MICROBIOL RES

• T. Mukutirwa

• M.H. McCrady
• Smruti Sohani
• Iqbal Sanjeeda
• Recruit researchers
• Join for free
• Login Email Tip: Most researchers use their institutional email address as their ResearchGate login Password Forgot password? Keep me logged in Log in or Continue with Google Welcome back! Please log in. Email · Hint Tip: Most researchers use their institutional email address as their ResearchGate login Password Forgot password? Keep me logged in Log in or Continue with Google No account? Sign up

File(s) under embargo

until file(s) become available

Optimizing Irrigation and Fertigation for Watermelon Production in Southern Indiana

Watermelon [ Citrullus lanatus (Thunb.) Matsum. & Nakai] is one of the world's top three most consumed fruits. Indiana cultivates approximately 7,000 acres of watermelons every year, ranking 6 th in the nation. More than 70% of this production is concentrated in and around Knox County, making Southern Indiana a key region for watermelon production in the States. Despite its significance, watermelon production faces many challenges, including erratic rainfall patterns exacerbated by climate change. Enhanced irrigation management has emerged as a critical strategy in mitigating negative environmental effects and in optimizing fertilizer applications.

Currently, Southern Indiana farmers have incorporated different irrigation and fertilization practices into watermelon production, yet the effects on production outcomes remain poorly understood. To bridge this gap in knowledge, this study aims to explore the effects of existing practices on watermelon yield and develop irrigation guidelines for optimal production in the region. The experiment was conducted at Southwest Purdue Agricultural Center, Vincennes, Indiana, in 2022 and 2023. Four treatments were applied: High Irrigation, Low Irrigation, No Irrigation, and Fertigation. Fertigation treatment received the same water application as the High Irrigation treatment. Fertilizers were applied pre-plant in the High, Low, and No irrigation treatments, while frequent fertigation was applied to the Fertigation Treatment. Soil moisture sensors measuring volumetric water content were used for irrigation decisions. In 2022, the irrigation thresholds were set at 15% water depletion at 1-ft depth for High Irrigation and Fertigation treatment, and 2-ft depth for Low Irrigation. In 2023, the irrigation threshold for Low Irrigation was adjusted to 40% water depletion at 1-ft depth.

While soil moisture levels in the bed at the different depths varied notably among treatments, no significant differences in yield by weight were observed. The minimal impact of irrigation on watermelon yield suggests that rainfall provides sufficient water, preventing yield-reducing stress. However, the Fertigation and High Irrigation treatments yielded more fruit than the Low Irrigation and No Irrigation treatments. The dry periods in both years coincided with the watermelon fruit setting stages that may have contributed to the lower fruit set in the Low Irrigation and No Irrigation treatments. Fertigation showed a higher early yield than the other treatments in 2022. Analysis of soil and tissue nitrogen levels indicated that sole nitrogen application before planting could result in excessive soil nitrogen levels during vegetative growth. This excess nitrogen might delay flowering and harvest. This project offers insights into enhancing irrigation and fertilization practices for watermelon production in southern Indiana.

Degree Type

• Master of Science
• Horticulture

Campus location

• West Lafayette

Advisor/Supervisor/Committee Chair

Additional committee member 2, additional committee member 3, additional committee member 4, usage metrics.

• Horticultural crop growth and development
• Agricultural management of nutrients

Chemtrade Logistics Offers A 7.2% Yield With A 48% Payout Ratio

• Chemtrade Logistics focuses on sulfur and water chemicals and electrochemicals.
• Q1 results show a decrease in revenue but strong distributable cash flow and manageable payout ratio.
• Series H convertible debentures offer a 7% yield with potential for conversion if the share price increases.
• Looking for a helping hand in the market? Members of European Small-Cap Ideas get exclusive ideas and guidance to navigate any climate. Learn More »

LSOphoto/iStock via Getty Images

Introduction

I have a substantial long position in a convertible debenture issued by Chemtrade Logistics ( OTC:CGIFF ) ( TSX: CHE.UN:CA ), a company focusing on two specific divisions: S ulfur and water chemicals and electrochemicals. I don’t mind being a creditor of a strong company, but I definitely plan to follow up on my investments at least once per quarter to make sure I have nothing to worry about.

Chemtrade Investor Relations

This article is an update to previous articles, so to get a better understanding of the company’s business model and past performance, I’d like to refer you to the older articles on Chemtrade. This recent presentation ( published in May ) also will be very helpful to get a better understanding of Chemtrade’s business.

The sustaining free cash flow remained strong in Q1

While the income statement is not as important as the sustaining free cash flow result, it obviously does provide a good look behind the scenes to ensure the company’s performance remains strong.

As you can see below, the total revenue of Chemtrade was C$418M in the first quarter of the year, which is a decrease of in excess of 10% compared to the revenue in Q1 of last year. Fortunately, Chemtrade was also able to reduce its COGS, resulting in a gross profit of C$98M but I was slightly disappointed when I saw the SG&A expenses increased by almost C$10M on a YoY basis.

As the income statement above shows, SG&A expenses increased to C$38.2M and this definitely put pressure on the bottom line result. The pre-tax income decreased to C$54.2M resulting in a net profit of C$42M. Not bad in the greater scheme of things, but definitely much worse than the almost C$80M in net profit in Q1 2023. That being said, the company was able to record a non-recurring finance income in Q1 2023 and this had a rather sizeable impact on the pre-tax and net income. That being said, the Q1 EPS of C$0.36 per share is still quite decent compared to the current share price of Chemtrade, which is currently trading below C$10/share.

In Chemtrade’s case, not the reported EPS but the distributable cash flow is what really matters. And as you can see below, the company generated almost C$60M in distributable cash flow and this represents C$0.51 per unit.

Chemtrade currently pays a monthly distribution of C$0.055 per share which means that based on the Q1 result, the payout ratio was just 32%. While that was indeed higher than the payout ratio of just 20% in Q1 2023, let’s not forget Chemtrade’s financial performance is now normalizing after a few years of tailwinds.

Looking at the full-year guidance, Chemtrade expects to generate C$415M in adjusted EBITDA (I am using the midpoint of the guidance shown below ) and after deducting C$50M in interest payments, C$60M in lease payments and C$40M in cash taxes, Chemtrade will generate C$265M in cash flow.

We see total capex will be C$195M which at the very least means Chemtrade will generate C$70M in free cash flow, but as you can see above, there's up to C$90M earmarked for growth. Using the high end of the maintenance capex (C$105M), the underlying distributable cash flow would be C$160M, or C$1.37 per share.

And that makes the current share price of just over C$9 still attractive.

I'm still overweight the debentures

I have a pretty substantial long position in the Series H convertible debentures issued by Chemtrade. Those debentures mature on June 30, 2028, (so in four years from now) and have a 7% coupon . This series of debentures is currently trading around par. As you can see below, the conversion price is C$12.85 per share which means the share price would have to increase by approximately 40% before the debentures are "in the money" and converting it into stock makes more sense.

For now, I'm considering the convertible debentures to be "straight" debentures: Considering the conversion price is substantially higher than the current share price, I will just assume the debentures won’t be converted. This means I’m receiving a 7% yield on this debt security (there's no withholding tax on interest payments made by Canadian companies).

I'm quite confident Chemtrade will have no issue to continue to cover its interest payments: In the first quarter of this year, the company booked a C$10.5M total interest expense, including C$7.3M on the four different issues of convertible debentures. That’s about C$42M in total interest expenses on an annualized basis, which should be very well covered by the anticipated C$265M in operating cash flow.

Secondly, the balance sheet also looks pretty decent from a creditor’s perspective. As you can see below, Chemtrade has C$27.5M in cash and a net debt of C$730M. This represents just over two times the adjusted EBITDA (also adjusted for lease payments) which isn’t too big of a deal, while the total amount of equity on the balance sheet is approximately C$741M.

And in case there's any need, Chemtrade could simply just suspend or lower the distributions on the common equity to save cash, but I don’t expect that will be necessary.

Investment thesis

I have a long position in the Series H convertible debentures issued by Chemtrade. I think the 7% yield is a fair compensation given the very strong EBITDA, reported free cash flow result and distributable cash flow result of Chemtrade. According to the analyst consensus, Chemtrade’s EBITDA will remain relatively flat in the next few years which obviously is a good situation for the debenture holders as the cash flows will remain strong.

The common units are currently yielding 7.2% which still is an attractive compensation considering the distributable cash flow will likely come in around C$1.37 per share, resulting in a payout ratio of just around 50%. I may consider adding the common units to my portfolio as well, despite the recent share price increase since my previous article.

Editor's Note: This article discusses one or more securities that do not trade on a major U.S. exchange. Please be aware of the risks associated with these stocks.

Consider joining European Small-Cap Ideas to gain exclusive access to actionable research on appealing Europe-focused investment opportunities, and to the real-time chat function to discuss ideas with similar-minded investors!

This article was written by

The Investment Doctor is a financial writer, highlighting European small-caps with a 5-7 year investment horizon. He strongly believes a portfolio should consist of a mixture of dividend and growth stocks.

Analyst’s Disclosure: I/we have no stock, option or similar derivative position in any of the companies mentioned, and no plans to initiate any such positions within the next 72 hours. I wrote this article myself, and it expresses my own opinions. I am not receiving compensation for it (other than from Seeking Alpha). I have no business relationship with any company whose stock is mentioned in this article. I have no position in Chemtrade's common units, but I have a substantial long position in Chemtrades Series H convertible debentures.

Seeking Alpha's Disclosure: Past performance is no guarantee of future results. No recommendation or advice is being given as to whether any investment is suitable for a particular investor. Any views or opinions expressed above may not reflect those of Seeking Alpha as a whole. Seeking Alpha is not a licensed securities dealer, broker or US investment adviser or investment bank. Our analysts are third party authors that include both professional investors and individual investors who may not be licensed or certified by any institute or regulatory body.

Recommended For You

About cgiff stock.

More on CGIFF

Related stocks.

Trending Analysis

Trending news.