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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Assessing the potential risk of failing to maintain water supply in the Rand Water area / Londani Phillip Lithole

Lithole, Londani Phillip January 2015 (has links)
The research study focused on assessing the potential risk of failing to maintain water supply in the Rand Water area. The study analysed all factors and areas that contributes to water supply in the Rand Water area; this included municipalities supplied by Rand Water, the Department of Water Affairs and other factors that directly affect Rand Water supply such as population growth, increased urbanisation and acid mine drainage. The objectives of the study were: (a) is to determine the potential risk of failing to maintain supply in the Rand Water supply area, in other words, the likeliness of water not being supplied adequately to customers. (b) generate timely and credible information to determine the understanding, awareness, and acknowledgement by the sampled management group of the existence of the potential water supply risk in the Rand Water supply area. This will be done through a quantitative study. The research study approach that was utilized was a quantitative methodology; this approach included the distribution of questionnaires to all relevant stakeholders in the Rand Water supply area. To address the problems that are highlighted in the problem statement and achieve the objectives of the study these answered questionnaires were then sent to a Statistical consultant at North-West University‟s Potchefstroom Campus, to be analysed using an SPSS Version 21 statistical program. The questionnaires were divided into the three big municipal customers, these municipalities combined takes a total of 74.35% of Rand Water supply; these are Johannesburg Water which is part of the City of Johannesburg Metropolitan Municipality, Ekurhuleni Metropolitan Municipality, Tshwane Metropolitan Municipality and other small municipalities and the Department of Water Affairs‟ officials. Many previous studies also were assessed to be able to help this study establish the seriousness of the water challenge, the amount of work that has already been done, factors contributing to the problem and finally, measures that can be put in place to address the problem. The results that were obtained for this study provided many relationships between this study‟s selected variables and also highlighted the need to put certain strategies in place to be able to control the growing demand for water in the Rand Water system. The name of the Department of Water Affairs has changed many times over the year. It used to be called DWAF (Department of Water Affairs and Forestry, then DWEA (Department of Water and Environmental Affairs, then DWA (Department of Water Affairs) and it has recently been changed to DWS (Department of Water and Sanitation. For the purposes of this study this department will be called DWA (The Department of Water Affairs) The results were very relevant as most of the relationships were found between variables that are practically supposed to be related in order for the problem to be dealt with fruitfully. From these results it could be concluded that the risk of failing to maintain water supply in the Rand Water supply area does exist, if certain factors were allowed to trend the way they‟ve been trending without measures in place to counteract them. It could also be concluded that certain measures have been initiated to deal with the problem; this included water demand management. Results indicated that collective efforts from all stakeholders in the Rand Water supply area will be crucial in addressing the water supply challenge and avoid future failure to supply. To close the gap between previous research studies and this research study recommendations were made. Areas of future research were also highlighted; these are areas that can add value in providing valued information to help the challenge of water shortage in the Rand Water supply area. This area of future research studies will also be crucial in identifying other external factors that were not highlighted in the study but contribute to the problem. This area of future research studies will also help when implementing turnaround strategies to avoid the risk of failing to maintain supply in the Rand Water area as it will be able to highlight a different strategy that deals with the problem holistically. / MBA, North-West University, Potchefstroom Campus, 2015
42

Inventory Optimization through Integration of Marketing and Supply Chain Management

Karimipour Hadadan, Elham January 2016 (has links)
Purpose: This study aims to find how the integration between marketing and operations can improve demand management in order to have efficient inventory level and avoid excess inventory. Method used: In order to have optimize inventory level and managing demand, integrating business process between marketing, supply planning and inventory management team was considered in this study. Qualitative data from nine interviews among three direct sales cosmetics companies was gathered. Findings: Empirical findings address excess inventory is caused by several issue in the company as poor management of demand forecasting, wide product portfolio, long lead time, the lack of sharing information between the company and its suppliers and ineffective strategy to avoid excess inventory within the company. Regarding to improve forecast accuracy and manage demand, findings indicate the role of marketing in obtaining knowledge about customer insight is not good enough. Practical Implication: It is critical that works and plans from each function be integrated to optimize inventory. In order to support optimize inventory strategy all pertinent departments must continue reviewing meeting with the aim to reach a consensus about the products planning for the both side of demand and operation align with overall strategic goals of the company. Contribution: Empirical data demonstrate the best way for effective implication of demand management occurs when marketing can provide demand information in time, as well as supply chain management can react flexibly to demand changes in time. Moreover, the lack of integration between marketing and supply chain management is a major barrier in optimizing inventory.
43

Probabilistic analysis of monthly peak factors in a regional water distribution system

Kriegler, Benjamin Jacobus 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The design of a water supply system relies on the knowledge of the water demands of its specific end-users. It is also important to understand the end-users’ temporal variation in water demand. Failure of the system to provide the required volume of water at the required flow-rate is deemed a system failure. The system therefore needs to be designed with sufficient capacity to ensure that it is able to supply the required volume of water during the highest demand periods. In practice, bulk water supply systems do not have to cater for the high frequency, short duration high peak demand scenarios of the end-user, such as the peak hour or peak day events, as the impact of events is reduced by the provision of water storage capacity at the off-take from the bulk supply system. However, for peak demand scenarios with durations longer than an hour or a day, depending on the situation, the provision of sufficient storage capacity to reduce the impact on the bulk water system, becomes impractical and could lead to potential water quality issues during low demand periods. It is, therefore, a requirement that bulk water systems be designed to be able to meet the peak weekly or peak month end-user demands. These peak demand scenarios usually occur only during a certain portion of the year, generally concentrated in a two to three month period during the drier months. Existing design guidelines usually follow a deterministic design approach, whereby a suitable DPF is applied to the average annual daily system demand in order to determine the expected peak demand on the system. This DPF does not account for the potential variability in end-user demand profiles, or the impact that end-storage has on the required peak design factor of the bulk system. This study investigated the temporal variations of end-user demand on two bulk water supply systems. These systems are located in the winter rainfall region of the Western Cape province of South Africa. The data analysed was the monthly measured consumption figures of different end-users supplied from the two systems. The data-sets extended over 14 years of data. Actual monthly peak factors were extracted from this data and used in deterministic and probabilistic methods to determine the expected monthly peak factor for both the end-user and the system design. The probabilistic method made use of a Monte Carlo analysis, whereby the actual recorded monthly peak factor for each end-user per bulk system was used as an input into discrete probability functions. The Monte Carlo analysis executed 1 500 000 iterations in order to produce probability distributions of the monthly peak factors for each system. The deterministic and probabilistic results were compared to the actual monthly peak factors as calculated from the existing water use data, as well as against current DPFs as published in guidelines used in the industry. The study demonstrated that the deterministic method would overstate the expected peak system demand and result in an oversized system. The probabilistic method yielded good results and compared well with the actual monthly peak factors. It is thus deemed an appropriate tool to use to determine the required DPF of a bulk water system for a chosen reliability of supply. The study also indicated the DPFs proposed by current guidelines to be too low. The study identified a potential relationship between the average demand of an end-user and the expected maximum monthly peak factor, whereas in current guidelines peak factors are not indicated as being influenced by the end-user average demand. / AFRIKAANSE OPSOMMING: Die ontwerp van ‘n watervoorsiening stelsel berus op die kennis van die water aanvraag van sy spesifieke eindverbruikers. Dit is ook belangrik om ‘n begrip te hê van die tydelike variasie van die eindverbruiker se water-aanvraag. Indien die voorsieningstelsel nie in staat is om die benodigde volume water teen die verlangde vloeitempo te kan lewer nie, word dit beskou as ‘n faling. Die stelsel word dus ontwerp met voldoende kapasiteit wat dit sal in staat stel om die benodigde volume gedurende die hoogste aanvraag periodes te kan voorsien. In die praktyk hoef grootmaat water-voorsiening stelsels nie te voldoen aan spits watergebeurtenisse met hoë frekwensie en kort duurtes, soos piek-dag of piek-uur aanvraag nie, aangesien hierdie gebeurtenisse se impak op die grootmaat stelsel verminder word deur die voorsiening van wateropgaring fasiliteite by die aftap-punte vanaf die grootmaatstelsels. Nieteenstaande, vir piek-aanvraag gebeurtenisse met langer duurtes as ‘n uur of dag, raak die voorsiening van voldoende wateropgaring kapasiteit by die aftap-punt onprakties en kan dit selfs lei tot waterkwaliteits probleme. Dit is dus ‘n vereiste dat grootmaat watervoorsienings stelsels ontwerp moet word om die piek-week of piek-maand eindverbruiker aanvrae te kan voorsien. Hierdie piek-aanvraag gebeurtenisse vind algemeen in gekonsentreerde twee- of drie maand periodes tydens die droeër maande plaas. Bestaande ontwerpsriglyne volg gewoonlik ‘n deterministiese ontwerp benadering, deurdat ‘n voldoende ontwerp spits faktor toegepas word op die gemiddelde jaarlikse daaglikse stelsel aanvraag om sodoende te bepaal wat die verwagte spits aanvraag van die stelsel sal wees. Hierdie ontwerp spits faktor maak nie voorsiening vir die potensiële variasie in die eindverbruiker se aanvraag karakter of die impak van die beskikbare water-opgaring fasiliteit op die benodigde ontwerp spits faktor van die grootmaat-stelsel nie. Hierdie studie ondersoek die tydelike variasie van die eindverbruiker se aanvraag op twee grootmaat watervoorsiening stelsels. Die twee stelsels is geleë in die winter reënval streek van die Wes-Kaap provinsie van Suid-Afrika. Die data wat geanaliseer is was die maandelikse gemeterde verbruiksyfers van verskillende eindverbruikers voorsien deur die twee stelsels. Die datastelle het oor 14 jaar gestrek. Die ware maand piekfaktore is bereken vanaf die data en is in deterministiese en probabilistiese metodes gebruik om die verwagte eindverbruiker en stelsel ontwerp se maand spits-faktore te bereken. Die probabilistiese metode het gebruik gemaak van ‘n Monte Carlo analise metode, waardeur die ware gemeette maand spits-faktor vir elke eindverbruiker vir elke grootmaatstelsel gebruik is as invoer tot diskrete waarskynlikheids funksies. Die Monte Carlo analise het 1 500 000 iterasies voltooi om waarskynlikheids-verdelings van elke maand spitsfaktor vir elke stelsel te bereken. Die deterministiese en probabilistiese resultate is vergelyk met die ware maand spits faktore soos bereken vanuit die bestaande waterverbruik data, asook teen huidige gepubliseerde ontwerp spits-faktore, wat in die bedryf gebruik word. Die studie het aangetoon dat die deterministiese metode te konserwatief is en dat dit die verwagte piekaanvraag van die stelsel sal oorskat en dus sal lei tot ‘n oorgrootte stelsel. Die probabilistiese metode het goeie resultate opgelewer wat goed vergelyk met die ware maand piek-faktore. Dit word gereken as ‘n toepaslike metode om die benodigde ontwerp spits-faktor van ‘n grootmaat-watervoorsiening stelsel te bepaal vir ‘n gekose voorsieningsbetroubaarheid. Die studie het ook aangedui dat die ontwerps piek-faktore voorgestel deur die huidige riglyne te laag is en dat dit tot die falings van ‘n stelsel sal lei. Die studie het ‘n moontlike verwantskap tussen die gemiddelde daaglikse wateraanvraag van die eindverbruiker en die verwagte maksimum maand spits faktor geïdentifiseer, nademaal die piek-faktore soos voorgestel deur die huidige riglyne nie beïnvloed word deur die eindverbruiker se gemiddelde verbruik nie.
44

Guideline for a robust assessment of the potential savings from water conservation and water demand management

Wegelin, Willem Adriaan 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Water loss in water distribution systems has been studied for many years in many countries and is continuously leading to the development of new concepts and theories, publications, guidelines and software models. Despite these developments, 45 % of water utilities in South Africa still do not understand the extent of water losses in the distribution systems that they operate (Wegelin et al., 2012:27). It is important, in terms of water services planning, that a realistic estimate of the potential savings from individual water conservation and water demand management (WC/WDM) measures is made as it impacts directly on water security and business matters. If the potential savings were incorrectly or inaccurately calculated, additional resources might have to be developed at short notice to be able to supply in the demand. Advanced software models, such as BENCHLEAK, PRESMAC, SANFLOW, AQUALITE and ECONOLEAK (McKenzie & Bhagwan, 2000) have been developed to quantify the extent of physical and commercial losses in water supply systems. Similar advanced models are available for estimating water demand. Such advanced models require numerous input parameters, each of which needs to be described accurately. The predicament is that such complex models are often simply not applicable in certain areas with limited resources and limited input data. In contrast, robust guidelines that are relatively insensitive to input parameters are useful in developing countries, where all input values for complex water demand models may be unavailable or inaccurate. No robust method has yet been developed for estimating the potential water savings that would result from WC/WDM interventions. A need thus exists to estimate water savings in a robust way with relatively few inputs. This guideline promotes the development of a robust WC/WDM strategy, based on a systematic and pragmatic approach, which requires less initial funding and develops with time. The methodologies developed by the Water Loss Task Force (WLTF) of the International Water Association (IWA), were used to develop six basic steps, which need to be followed to develop a WC/WDM strategy. During the six steps, the minimum requirements for implementing WC/WDM will be defined, the current water losses and efficiencies will be determined, and potential targets will be set based on national and international benchmarks. Once targets have been set, 20 key interventions were identified to address water use efficiency, and commercial and physical losses. The motivation behind each intervention is provided based on best practice, case studies and legal requirements. The model ensures that the potential savings from the various interventions are sufficient to ensure that targets are achieved, and if not, that targets must be revised. The potential savings from interventions are based on literature reviews and new formulas developed as part of this guideline. The results from the various interventions would enable the water utility to prioritise interventions. The guideline concludes with a flow diagram describing the methodology.
45

The impact of domestic water user cultures on water efficiency interventions in the South East of England : lessons for water demand management

Knamiller, C. January 2011 (has links)
The need for a more sustainable approach to water consumption has increasingly gained attention in the last decade. The domestic sector accounts for over half of abstracted water in the UK and, as such, has become a major target for water efficiency interventions. Current research and water efficiency interventions are dominated by a positivist approach, focusing on a limited range of factors that can be quantitatively measured. This thesis questions the dominant approach and argues that a more holistic overview of water efficiency can be achieved through the consideration of socio-technical and behavioural theories. Taking a more constructivist approach, this research draws on four theories from socio-technical and behavioural fields and combines them to create a framework for the analysis of water efficiency interventions. The framework is applied to two case studies, exploring water users' perceptions of water, water supply, personal water use, and their responses to the water efficiency interventions. The case studies were selected to provide examples of current mainstream approaches to water demand management. Research methods used included semi-structured interviews and observation. The research findings support the argument that the current dominant approach to domestic water efficiency interventions is limited and, in some cases, ineffectual. Issues of trust, knowledge, motivation and the relationships between water users and water companies were raised. The thesis concludes that the use of a constructivist perspective could help to provide a more effective approach to understanding and improving water demand management.
46

Residential Outdoor Water Use in Tucson, Arizona: Geospatial, Demographic and Temporal Perspectives

Halper, Eve Brook January 2011 (has links)
Outdoor water use by single-family residences in the desert city of Tucson, Arizona is investigated as a multi-scaled coupled human-environment system, using remotely sensed images, GIS data, household water use records and survey responses. Like many desert cities, Tucson's municipal water system faces stresses at multiple spatial and temporal scales: rising demand, limited supplies, competition for distant resources and the likelihood of shortages due to regional climate change. Though the need for demand management is recognized, conflict between the long-term regional scale of the ecosystem that sustains Tucson's water supply and the short-term, local scale of the municipal utility results in a "lack of fit", shown here as the inability to reduce consumption to sustainable levels.While direct regulation of outdoor water use has not been successful, geographic research suggests that modification of the built environment, the focus of the three studies comprising this dissertation, holds promise as a demand management strategy. The first study is a spatial analysis of survey responses on outdoor water use practices during a drought. Next, the potential for substituting common amenities (irrigated landscapes and swimming pools) for private ones is investigated. Residential use was found to be sensitive to park proximity, greenness (proxied by the Normalized Difference Vegetation Index), size and presence of a park pool. Most small parks were net water savers; large parks offered the opportunity to substitute reclaimed water for potable supplies.The last study correlates long-term Landsat-based vegetation and water use trends and integrates these with a spatial analysis of kinetic temperatures. Findings indicate that despite reduced water use, Tucson became greener over the 1995 - 2008 period. This effect is attributed to a pulse of vegetation establishment in response to a shift in the El Niño - Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) around 1976 and to irrigation prior to the study period. I conclude that although the coupled human-environment system of Tucson's municipal water supply and use practices is complex, there are scale-dependent competitive advantages to be gained through thoughtful modification of the built environment.
47

Stakeholder accountability in water demand management in South-east Botswana.

Boitumelo-Mfula, Tumisang Sanggy January 2006 (has links)
<p>Botswana's population and water demand are growing at a high rate particularly in the dry south eastern part of the country. In 1999, a Water Conservation Policy and Strategy framework document was formulated to guide a transition from a supply driven water management approach to water demand management. This study investigated whether there was a disparity between the framework policy and strategy recommendations and their actual implementation.</p>
48

Rainwater harvesting in the UK : a strategic framework to enable transition from novel to mainstream

Ward, Sarah January 2010 (has links)
The approach to water management worldwide is currently in transition, with a shift evident from purely centralised infrastructure to greater consideration of decentralised technologies, such as rainwater harvesting (RWH). Initiated by recognition of drivers including increasing water demand and increasing risk of flooding, the value of RWH is beginning to filter across the academic-policy boundary. However, in the UK, implementation of RWH systems is not straight forward; social and technical barriers, concerns and knowledge gaps exist, which currently restrict its widespread utilisation. Previously, these issues have been examined independently. The research described in this thesis highlights the need for interdisciplinary working to lower the barriers and resolve the concerns. Consequently, a combination of social and engineering research perspectives, methods and analysis is utilised to achieve the aim of the research: the production of a strategic framework to support the implementation of RWH in the UK. The framework is the culmination of empirically derived social and technical evidence bases including: surveys with householders and architects; interviews with small to medium enterprises (SMEs); a design and performance evaluation of a non-domestic RWH system; non-domestic water closet (WC) monitoring to develop a demand profile and a water quality study and health impact assessment (HIA) of a non-domestic RWH system. Results indicate that householders were willing but not able to implement RWH, due to financial constraints and perceived maintenance burdens. For SMEs 5 ‘implementation deficit categories’ were identified, which undermined their ability to implement. The use of continuous simulation tools, with appropriate data, need to be promoted and the non-domestic demand profile derived was distinctly different to the well-established domestic profile, yielding implications for system design. The non-domestic RWH system was able to achieve an average water saving efficiency of 97% for the period monitored and the HIA quantified the risk to health as being within the recognised screening level. Triangulation of the results into an integrated socio-technical evidence base facilitated the identification of three core strategy aims, their corresponding actions and actors (stakeholder groups). The overall strategic framework is presented in the form of a Venn diagram. It is unlikely the comprehensive nature of the strategic framework would have been achieved, if the interdisciplinary process had not been undertaken. Therefore adoption of a socio-technical approach to implementation is vital, if RWH in the UK is to transition from novel to mainstream.
49

QUICK LINK SELECTION METHOD BY USING PRICING STRATEGY BASED ON USER EQUILIBRIUM FOR IMPLEMENTING AN EFFECTIVE URBAN TRAVEL DEMAND MANAGEMENT

Zargari, Shahriar Afandizadeh, Mirzahossein, Hamid, Chiu, Yi-Chang 02 March 2017 (has links)
This paper presents a two-stage model of optimization as a quick method to choose the best potential links for implementing urban travel demand management (UTDM) strategy like road pricing. The model is optimized by minimizing the hidden cost of congestion based on user equilibrium (MHCCUE). It forecasts the exact amount of flows and tolls for links in user equilibrium condition to determine the hidden cost for each link to optimize the link selection based on the network congestion priority. The results show that not only the amount of total cost is decreased, but also the number of selected links for pricing is reduced as compared with the previous toll minimization methods. Moreover, as this model just uses the traffic assignment data for calculation, it could be considered as a quick and optimum solution for choosing the potential links.
50

Stakeholder accountability in water demand management in South-east Botswana

Boitumelo-Mfula, Tumisang Sanggy January 2006 (has links)
Magister Philosophiae - MPhil / Botswana's population and water demand are growing at a high rate particularly in the dry south eastern part of the country. In 1999, a Water Conservation Policy and Strategy framework document was formulated to guide a transition from a supply driven water management approach to water demand management. This study investigated whether there was a disparity between the framework policy and strategy recommendations and their actual implementation. / South Africa

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