[ES] El Reino de Arabia Saudí está experimentando un importante crecimiento económico, industrial, comercial y demográfico. Este crecimiento, a su vez, provoca un aumento de la demanda de agua en la región. Además del crecimiento demográfico, también la industrialización y la modernización han ejercido una presión cada vez mayor sobre las infraestructuras hídricas del país. Urge aumentar la disponibilidad de agua para satisfacer la demanda prevista y mantener la seguridad y fiabilidad de los sistemas hídricos. Por lo tanto, es imperativo encontrar soluciones que mejoren la eficiencia del sistema hídrico del país. Un elemento clave en este esfuerzo es comprender y clasificar cómo se consume el agua con sus microcomponentes dentro de varios segmentos. La tesis recopila conocimientos precisos sobre las pautas y tendencias del consumo municipal de agua para comprender mejor los patrones de consumo y los comportamientos de los consumidores, así como desarrollar estimaciones e hipótesis preliminares. De este modo, se impulsará el modelo de demanda de agua municipal en el país para que sea capaz de hacer frente a diferentes escenarios y limitaciones. El desarrollo del modelo municipal de demanda de agua ha mostrado la necesidad de disponer de datos estadísticos y de facturación del agua fiables. Éstos constituyen el punto de partida de la previsión y deben estar disponibles con una resolución suficientemente alta. El modelo aquí presentado proporciona un marco para que nuevos desarrollos futuros. Los resultados del análisis también determinarán los factores y categorías utilizados en el modelo. El modelo se centra en la demanda de agua no residencial. No obstante, se incluyen previsiones separadas para la categoría residencial a fin de permitir la extrapolación de los resultados y el análisis top-down para un enfoque más preciso de las previsiones y, también, para una mejor comprensión general de los comportamientos de consumo de agua de la población. / [CA] El Regne de l'Aràbia Saudita està experimentant un important creixement econòmic, industrial, comercial i demogràfic. Aquest creixement, al seu torn, provoca un augment de la demanda d'aigua a la regió. A més del creixement demogràfic, també la industrialització i la modernització han exercit una pressió cada vegada major sobre les infraestructures hídriques del país. Urgeix augmentar la disponibilitat d'aigua per a satisfer la demanda prevista i mantindre la seguretat i fiabilitat dels sistemes hídrics. Per tant, és imperatiu trobar solucions que milloren l'eficiència del sistema hídric del país. Un element clau en aquest esforç és comprendre i classificar com es consumeix l'aigua amb els seus microcomponents dins de diversos segments. La tesi recopila coneixements precisos sobre les pautes i tendències del consum municipal d'aigua per a comprendre millor els patrons de consum i els comportaments dels consumidors, així com desenvolupar estimacions i hipòtesis preliminars. D'aquesta manera, s'impulsarà el model de demanda d'aigua municipal al país perquè siga capaç de fer front a diferents escenaris i limitacions. El desenvolupament del model municipal de demanda d'aigua ha mostrat la necessitat de disposar de dades estadístiques i de facturació de l'aigua fiables. Aquests constitueixen el punt de partida de la previsió i han d'estar disponibles amb una resolució prou alta. El model ací presentat proporciona un marc perquè nous desenvolupaments futurs. Els resultats de l'anàlisi també determinaran els factors i categories utilitzats en el model. El model se centra en la demanda d'aigua no residencial. No obstant això, s'inclouen previsions separades per a la categoria residencial a fi de permetre l'extrapolació dels resultats i l'anàlisi *top-*down per a un enfocament més precís de les previsions i, també, per a una millor comprensió general dels comportaments de consum d'aigua de la població. / [EN] The Kingdom of Saudi Arabia is undergoing substantial economic, industrial, commercial, and population growth. This growth, in turn, leads to increased water demand in the region. In addition to population growth, industrialization and modernization have placed increasing pressure on KSA's water infrastructure. There is an urgent need to increase the water capacity to meet the projected demand and maintain the water systems' security and reliability. Therefore, it is imperative to find solutions that improve the efficiency of the Kingdom's water system. A key element in this effort is understanding and classifying how water is consumed with its micro-components within various segments. The thesis aims to collect precise knowledge about municipal water consumption patterns and trends to understand water consumption patterns and consumer behaviours better and develop preliminary estimates and assumptions. This will drive the municipal water demand model in KSA to be capable of dealing with different scenarios and constraints. The development of the municipal water demand model highlighted the need for reliable statistical and water billing data. These form the starting point of the forecast and need to be available at a high enough resolution. The model provides a framework for the required data to be built on further. The analysis results will also determine the drivers and categories used in the model. The model focuses on the non-Residential water demand. Still, separate forecasts are included for the residential category to enable the extrapolation of the results and downward analysis for a more accurate and cost-effective bottom-up approach to forecasting and an overall better understanding of the population's water consumption behaviours. / Alhudaithi, M. (2023). A Sectorial Analysis of Municipal Water Consumption and Management in Saudi Arabia [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/201553

An approach to hybrid cooling technique is proposed using air jets which impinge on a triangular grooved surface with dry grooves and grooves containing water. One major application is for condensers of thermoelectric power plants. The heat and mass transfer analogy were successfully used to evaluate the simultaneous heat and mass transfer. Results showed that hybrid jet impingement produced high heat flux levels at low jet velocities and flow rates. Experimental results were used to characterize the resulting heat transfer under different conditions such as flow open area percentage, array orifices diameter and array to surface stand-off distance. The results have shown that jet impingement is capable of delivering high transfer rates with lower cooling cost rates compared to current industry conventional techniques. Water is efficiently used in hybrid jet impingement because evaporative energy is absorbed directly from the surface instead of cooling air to near wet-bulb temperature. / Master of Science / Array jet impingement cooling experiments were conducted on a triangular grooved surface with the surface at a constant temperature. Results showed that jet impingement can provide high transfer rates with lower rates of cooling cost in comparison to contemporary conventional techniques in the industry. Experiments on the triangular grooved surfaces were performed at dry and wet surface conditions. Under the dry conditions, the objective is to characterize the resulting heat transfer under varying operational conditions such as jet speed, array orifice diameter, array to surface stand-off distance, and flow open area percentage. Results from the triangular surface when dry showed less improvement in heat transfer than the rectangular grooved surface. A hybrid cooling technique approach was proposed and developed by using air jets impinging on a triangular grooved surface with the grooves containing water. The approach is being suggested and experimentally tested for its viability as an alternative to thermoelectric power plant cooling towers. Convection heat and mass transfer coefficients were experimentally measured for different wet coverage of the surface. Results showed that the hybrid jet impingement produced high heat flux levels at low jet velocities and flow rates. The highest heat transfer was consistently found with a 50% coverage of the surface. Hybrid jet impingement showed an improvement up to 500% in heat transfer as compared to jet impingement on a dry grooved surface.

Array jet impingement cooling experiments were performed on flat and grooved surfaces with the surface at a constant temperature. For the flat surface, power and temperature measurements were performed to obtain convection coefficients under a wide range of operating conditions such as jet speed, orifice to surface stand-of distance, and open area percentage. Cooling performance (CP) was calculated as the ratio between heat transfer and fan power. An empirical model was developed to predict jet impingement heat transfer taking into account the entrainment effects. Experimental results showed that jet impingement can provide high transfer rates with lower rates of cooling cost in comparison to contemporary conventional techniques in the industry. CP values over 279 were measured which are significantly higher than the standard values of 70 to 95 in current technology. The model enhanced prediction accuracy by taking into account the entrainment effects; an effect that is rarely considered in the literature. Experiments on the grooved surfaces were performed at dry and wet surface conditions. Under dry conditions, results showed 10%~55% improvement in heat transfer when compared to the flat surface. Improvement percentage tends to be higher at wider gaps between the array of orifices and the grooved surface. An improvement of 30%~40% was observed when increasing Re either by increasing orifice diameter or jet speed. Similar improvement was observed at higher flow open area percentages. No significant improvement in heat transfer resulted from decreasing the size of the grooves from 3.56mm to 2.54mm. Similarly, no noticeable change in heat transfer resulted from changing the relative position of the jets striking the surface at the top of the grooves to the bottom of the grooves. Deeper grooves with twice the depth gave statistically similar average heat transfer coefficients as shallower grooves. Under wet conditions, a hybrid cooling technique approach was proposed by using air jets impinging on a grooved surface with the grooves containing water. The approached is proposed and evaluated experimentally for its feasibility as an alternative for cooling towers of thermoelectric power plants. Convection heat and mass transfer coefficients were measured experimentally using the heat mass transfer analogy. Results showed that hybrid jet impingement provided high magnitudes of heat flux at low jet speeds and flow rates. High coefficients of performance CP > 3000, and heat fluxes > 8,000W/m2 were observed. Hybrid jet impingement showed 500% improvement as compared to jet impingement on a dry flat surface. CP values of hybrid jet impingement is 600% to 1,500% more as compared to performance of air-cooled condensers and wet cooling towers. Water use for hybrid jet impingement cooling is efficient since evaporation energy is absorbed from the surface directly instead of cooling air to near wet-bulb temperature. / PHD / This thesis explored the possibility of using air jets on the outside surface of a device that is used to condense steam. An experiment apparatus was used to imitate the conditions of steam condensation in the lab. A flat metallic surface was heated by placing an electric heater beneath it. The metallic surface was cooled using air jets coming out of orifices situated above the hot metallic surface. A fan, connected to an electric motor, was used to create the air jets. The amount of heat transfer was measured by measuring the electric power the heater consumed. This measured power was compared to the power needed to run the fan. The ratio of heat transfer to fan power is called the coefficient of performance CP. The CP values of more than 200 were obtained when air jets were used meaning that we need one kilowatt of mechanical power to remove 200 kilowatts of heat. This CP value is 300% more than the current technology used in the industry where CP ranges from 70 to 90. This means that we can build very efficient steam condensers for power plants. This type of condensers that uses air jets allows the power plant to be efficient and to be able to increase the amount of power generated without extra cost. Further enhancement of the CP can be achieved by making the hot surface grooved instead of flat with the grooves containing water. Air jets, coming out of orifices situated above the grooved surface, were used for cooling. The CP values of more than 3,000 were obtained when air jets were used with wet grooved surface. This CP values is 1,500% more than the current technology used in the industry. This type of condensers that uses air jets on wet grooves allows the power plant to be efficient and to be able to tremendously increase the amount of power generated without extra power and water costs.

No / his book explores a new framework of Adaptive Water Management (AWM) for evaluating existing approaches in urban water management. It highlights the need to adopt multidisciplinary strategies in water management while providing an in-depth understanding of institutional interactions amongst different water related sectors. The key characteristics of AWM i.e. polycentric governance, organisational flexibility and public participation are investigated and described through a critical review of the relevant literature. The book presents an empirical case study undertaken in a selected developing-country city to investigate the potential gaps between the current water management approaches and possible implementation of AWM. Feasibility of AWM operations is examined in an environment surrounded by established water management structure with centralised governance and an institutional process based on technical flexibility. The key elements of AWM performance are (re)structured and transformed into decision support systems. Multi criteria decision models are developed to facilitate quantification and visualization of the elements derived from the case study, which is involved with water companies and water consumers. The book describes how the concept of AWM, along with structuring suitable decision support systems, can be developed and applied to developing-country cities. The book highlights the barriers for applying the AWM strategies that include established centralised decision making, bureaucratic interactions with external organisations, lack of organisational flexibility within the institutions, and lack of recognition of public role in water management. The findings outline that despite the lack of adaptability in the current water management in the case study, as an example of developing countries, there are positive attitudes among water professionals and the public towards adaptability through public-institutional participation.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Concerns about the sufficiency of freshwater supplies and the impact of water shortages have placed sustainable water management on the global agenda. This is particularly relevant in South Africa, a country with precipitation rates well below the global average and water resources that have become highly polluted. The scarcity of water for consumption use and of unpolluted water bodies as recreational and environmental good highlights the need for an economic analysis of these issues. This dissertation investigates some economic aspects of water management in the South African context in two distinctive parts. Part One (Chapters 2 to 5) aims to provide an understanding of urban water demand and analyses water pricing as demand management tool. Part Two (Chapters 6 and 7) analyses the values people attach to water resources for recreational and environmental purposes. Quantitative methodological approaches are predominantly used to inform an economic perspective on water demand management. The extent of water scarcity is discussed in Chapter Two. South Africa is approaching physical water scarcity, but many poor households do not yet have access to water and basic sanitation facilities, i.e. there is also economic water scarcity. Given this background, Chapter Three focuses on water demand management as part of an integrated water management approach. The role of water prices is discussed, in particular the Increasing Block Tariff (IBT) structure which is predominantly used in South Africa. Chapter Four estimates the price elasticity of demand for water using household water consumption records obtained from the City of Cape Town (CCT). A distinctive feature of this case study is a survey undertaken to collect household information on demographic and water-use characteristics, as water databases are severely lacking in South Africa. The results show water demand to be mostly price inelastic, which concurs with findings from international empirical literature. Furthermore, higher-income households are found to be more sensitive to price changes, thus some reduction in water consumption can be achieved by increasing marginal prices at the upper end of the IBT structure. Chapter Five analyses the IBT structure as a redistributive tool. Particular attention is given to the Free Basic Water policy of South Africa, which allows each household to receive six kilolitres of water free per month. Empirical modelling indicates that the IBT structure in its current form holds limited benefits for the poor, given the state of service delivery in South Africa: the lack of access to the water network prevents the poorest households from being the recipients of the cross-subsidisation occurring in an IBT structure. Part Two studies urban water resources as recreational and environmental goods. The literature review of environmental valuation techniques in Chapter Six places particular emphasis on the Contingent Valuation Method. This method is applied in Chapter Seven, where the value of improving the environmental quality of a freshwater urban lake is analysed in a middle- to low-income urban area. Another survey was undertaken specifically for this purpose of gauging the willingness to pay for improved recreational facilities and water quality of Zeekoevlei. The results show that low-income households do attach value to urban environmental goods, a result which adds to our knowledge of willingness to pay for environmental goods in developing countries. / AFRIKAANSE OPSOMMING: Besorgdheid oor die toereikenheid van varswaterbronne en die impak van watertekorte het volhoubare waterbestuur op die wêreldagenda geplaas. Dit is veral relevant vir Suid- Afrika, 'n land met neerslagkoerse ver onder die wêreld gemiddelde en waterbronne wat hoogs besoedeld geword het. Die skaarsheid van water vir verbruik en van onbesoedelde waterbronne as ontspannings- en omgewingsproduk, beklemtoon die noodsaaklikheid vir 'n ekonomiese analise van hierdie kwessies. Hierdie proefskrif ondersoek sekere ekonomiese aspekte van waterbestuur in die Suid-Afrikaanse konteks, in twee dele. Deel Een (Hoofstukke Twee tot Vyf) beoog om insig te verskaf oor die stedelike vraag na water en analiseer die prys van water as 'n vraagbestuursmaatstaf. Deel Twee (Hoofstukke Ses en Sewe) ontleed die waarde wat mense heg aan waterbronne vir ontspannings- en omgewingsdoeleindes. Kwantitatiewe metodologiese benaderinge word hoofsaaklik gebruik om 'n ekonomiese perspektief op watervraag bestuur toe te lig. Die omvang van waterskaarsheid in Suid-Afrika word in Hoofstuk Twee bespreek. Hierdie hoofstuk dui aan dat Suid-Afrika besig is om fisiese waterskaarste te bereik, maar die land het ook baie arm huishoudings wat nog nie toegang tot water en basiese sanitasiefasiliteite het nie, dw.s. wat daar is ook ekonomiese waterskaarsheid. Gegewe hierdie agtergrond, fokus Hoofstuk Drie op watervraagbestuur, as deel van 'n geïntegreerde waterbestuursbenadering. Die rol van waterpryse word bespreek, veral die Stygende-Blok-Tarief (SBT) struktuur wat grotendeels in Suid-Afrika gebruik word. Hoofstuk Vier bepaal die pryselastisiteit van vraag vir water met behulp van huishoudelike waterverbruiksdata, verkry vanaf die Stad Kaapstad. 'n Kenmerkende eienskap van hierdie gevallestudie is die ingesamelde huishoudelike inligting oor demografiese en waterverbruik-eienskappe, aangesien daar ‘n groot tekort aan water-databasisse in Suid- Afrika is. Die uitslae toon dat watervraag meestal prysonelasties is, wat ooreenstem met bevindinge van ander empiriese literatuur. Verder word gevind dat hoё-inkomste huishoudings meer sensitief is vir prysveranderinge. Dus sal 'n afname in waterverbruik bewerkstellig kan word deur marginale pryse aan die hoёr kant van die SBT struktuur te verhoog. Hoofstuk Vyf ondersoek die SBT struktuur as 'n effektiewe herverdelingsmaatstaf. Spesifieke aandag word aan die Gratis Basiese Water-beleid van Suid-Afrika geskenk, wat voorsiening maak dat elke huishouding ses kiloliter water per maand verniet ontvang. Die bevindinge van empiriese modellering is dat die SBT struktuur, soos dit tans in Suid-Afrika toegepas word, beperkte voordele vir die armes inhou, gegewe die huidige stand van watervoorsiening in Suid-Afrika. As gevolg van die agterstand met betrekking tot toegang tot water, ontvang die heel armes nie die voordele van kruissubsidiёring wat plaasvind onder 'n SBT struktuur nie. Deel Twee bestudeer stedelike waterbronne as ontspannings- en omgewingsprodukte. Hoofstuk Ses verskaf 'n literatuur oorsig oor omgewingswaardasie tegnieke, met 'n spesieke fokus op die Kontingente Waardasie-metode. Hierdie metode word in Hoofstuk Sewe toegepas, waar die waarde van verbeteringe in die omgewingskwaliteit van 'n varswatermeer in 'n middel- tot lae-komste stedelike gebied ondersoek word. Nog 'n opname is gedoen met die doel om die bereidwilligheid om te betaal vir verbeterde ontspanningsfasiliteite en die waterkwaliteit van Zeekoevlei te meet. Die bevindinge toon dat lae-inkomste huishoudings wel waarde heg aan stedelike omgewingsprodukte.

Energy and environmental impacts are two factors that will influence urban region composition in the near future. One emerging issue is the effect on water usage resulting from changes in regional or urban transportation trends. With many regions experiencing stresses on water availability, transportation planners and users need to combine information on transportation-related water consumption for any region and assess potential impacts on local water resources from the expansion of alternative transportation modes. This thesis will focus on use-phase water consumption factors for multiple vehicle modes, energy and fuel pathways, roads, and vehicle infrastructure for a given transportation network. While there are studies examining life cycle impacts for energy generation and vehicle usage, few repeatable models exist for assessing overall water consumption across several transportation modes within urban regions. As such, the question is: is it possible to develop a traceable decision support model that combines and assesses water consumption from transportation modes and related mobility infrastructure for a given mobility network? Based on this, an object-oriented system model of transportation elements was developed using the Systems Modeling Language (SysML) and Model-Based Systems Engineering principles to compare water consumption across vehicle modes for assessing the resiliency of existing infrastructure and water resources. To demonstrate the intent of this model, daily network usage water consumption will be analyzed for current and alternative network scenarios projected by policies regarding the expansion of alternative energy. The model is expected to show variations in water consumption due to fluctuations in energy pathways, market shares, and driving conditions, from which the model should help determine the feasibility of expanding alterative vehicles and fuels in these networks. While spatially explicit data is limited compared to the national averages that are used as model inputs, the analytical framework within this model closely follows that of existing assessments and the reusable nature of SysML model elements allows for the future expansion of additional transportation modes and infrastructure as well as other environmental analyses.

Water is a vital component for human survival but unsustainable patterns of water consumption are still evident internationally. In South Africa, water conservation has traditionally been limited to the responsibility of the state, with little effort being made by the consumers. However, as water scarcity increasingly becomes a problem, government and residents need to find out how urban South Africans can access water and implement water conservation methods in their homes without the support of government supervision programmes. This study explores the relationship between urban residences in two different parts of Johannesburg (Meadowlands in Soweto and Florida in Roodepoort) and their consumption, perception and usage of water and its conservation. Based on interviews with residents from different backgrounds, the results of this research show that residents have varied but generally limited concern for water issues. Findings from this study indicate that for a resident to conserve water, the type of abode in which he/she lives is irrelevant. Whether the resident lives in suburban home or small government funded housing, the attitudes of the interviewees and the perceptions which they expressed regarding solutions to the water dilemma proved to be similar: people in these urban areas are aware of the importance of water conservation, however, there is limited practice thereof. / Geography / M. Sc. (Geography)

MPH / Department of Public Health

MENVM / Department of Geography and Geo-Information Science / See the attached abstract below

MESHWR / Department of Hydrology and Water Resources / Water scarcity has become a constraint for sustainable development in the higher education institutions in South Africa including University of Venda. Water infrastructure is one of the major challenges within higher education institutions, the existing water supply infrastructure is over 20 years old and was not planned for the current population. This study aimed at developing a water management plan for higher education institutions in South Africa using the University of Venda as a case study. A water resource management plan provides a road map for reducing water consumption while encouraging sustainable water utilisation. Evaluation was done within the institution to identify water sources, water resources infrastructure and water utilisation. The study employed questionnaire survey to collect data on water consumption, to evaluate issues of the institutional participation in resolving the water problems within the institution and deduce water wastage. Water supply data was obtained from meter readings and water invoices obtained from Vhembe District Municipality and University of Venda. The latter were used to determine water consumption within the institution. Based on the sample size, the results indicated the estimated amount of water consumed daily by UNIVEN population is 66 341.9 l/d excluding water utilised at the cafeteria, car wash and auditorium. The average water supplied to UNIVEN in 2017 was 67 642. 25 mega litres/month, this indicates that more water is supplied to the institution since the estimated institutional water demand excluding illegal students in the residence halls ranged between 415 740 l/d and 597 620 l/d of water while the estimated institutional water demand including illegal students varied between 282 2610 l/d and 406 6580 l/d. The latter further indicates that there is water wastage within the institution because the water supplied monthly to the institution was in mega litres as indicated in the invoices, but the results indicated that the amount of water utilised daily within the institution was in litres, this clearly shows that the respondents under estimated the amount of water they utilise. The average amount of water used by students residing on campus was 271 l/p/d to 735.5 l/p/d while day scholars and university staff use 55 l/p/d to 142.5 l/p/d. The average amount of water used for cleaning ranged between 1 318.5 l/d to 3 909 l/d while gardening usage ranged between 4600 l/d and 8 600 l/d. The School of Agriculture experimental farm uses 9 270.4 l/d and the university laundry was found to utilise 5 186 l/d. The university laboratories were found to utilise 125 l/d to 215 l/d per practical session with 3 to 4 practical sessions conducted per week. The study found that the total water used by construction workers for domestic purposes iv is 800 l/d. The utilisation trends showed that during the dry seasons, the university population generally used about twice as much water as compared to wet season because municipal water was supplemented by rain water for watering plants and washing the pavement. The survey results indicated that students residing in the university residences waste more water by allowing the tap to run while brushing teeth, washing dishes, excessive use of water to rinse clothes while doing laundry, opening showers and leaving the water running while waiting for a desired water temperature. Activities such as watering flowers and lawn in an unmonitored manner and pavement washing in which the hose pipe runs for several hours during watering and pavement washing result in water wastage. The university does not have an environmental or water education projects that encourage students and staff to use water efficiently. Water conservation measures are lacking in the institution because there are no policies and procedures that outline how water should be utilised. The developed water management plan for University of Venda outline the current water consumption, targets for reduction, drivers for reducing water consumption and water reduction strategies. This study recommends that the University targets to reduce potable water usage by 12% in the next 5 years. The latter has been highlighted in the proposed water management plan. The proposed plan further presents a suite of strategies to reduce water usage, improve institution water resources data and to plan for the future. Water utilisation within the institution has not been efficient due to water not being utilised in a sustainable manner. Sub-metering of each building, water awareness campaign, introduction of water utilisation policies, routine inspection and maintenance of infrastructure and appointing an environmental coordinator or working with water experts in the School of Environmental Sciences will help reduce water consumption within the institution. / NRF