Die Wasserknappheit wird aufgrund des Klimawandels voraussichtlich häufiger und intensiver auftreten, wodurch die Wasserkonkurrenz zunimmt und die Nahrungsmittelproduktion gefährdet wird. Höhere Temperaturen und längere Dürren können auch die Wasserverfügbarkeit der Tierhaltung beeinflussen. In Folge dessen kann es zu einer Verringerung des Futterangebots und damit zu einer Beeinträchtigung der Produktion kommen. Auch aus diesem Grund sind nachhaltige und resiliente Produktionssysteme erforderlich, um den Nahrungsmittelbedarf einer wachsenden Bevölkerung zu decken. Auf Pflanzenproduktion und Tierhaltung entfallen 72 % der weltweit entnommenen Wassermenge. Der Löwenanteil des Wasserbedarfs in der Tierhaltung besteht bei der Futtermittelproduktion. Weiterhin wird Wasser für die Trinkwasserbereitstellung sowie für die Reinigung und die Kühlung der Ställe benötigt. Tierproduktionssysteme müssen zukünftig mit betrieblichen Maßnahmen die Wasserressourcen besser ausnutzen. Die Steigerung der Wasserproduktivität in der Pflanzenproduktion und der Tierhaltung durch eine integrierte Bewirtschaftung und Steuerung der eingesetzten Wasserressourcen sind hierfür von entscheidender Bedeutung. Die Wasserproduktivität beschreibt das Verhältnis von Output zu Input: das Verhältnis von Output (z. B. kg Milch) zu produktivem Wasserinput (z. B. m³ Transpiration). Das Wasserinput umfasst den direkten Wassereinsatz und den indirekten Wassereinsatz, z.B. für zugekaufte Futtermittel. Die Ermittlung der Wasserproduktivität wird vor allem bei der Bewertung von landwirtschaftlichen Maßnahmen zur Verbesserung des Niederschlags- und technischen Wassereinsatzes in der Tier- und Pflanzenproduktion benötigt. Zur Steigerung der Wasserproduktivität und auch um die Umweltwirkungen der Tierhaltungssysteme zu verringern, bedarf es einheitlicher Methoden. Im Jahr 2019 hat die Food and Agriculture Organization of the United Nations (FAO) mit dem Livestock Environmental Assessment and Performance (LEAP) Partnership Richtlinien für die Bewertung der Wassernutzung in Tierproduktionssystemen und zugehöriger Lieferketten veröffentlicht. Zielsetzung ist die Ermittlung der Wasserflüsse auf betrieblicher Ebene, um einerseits die Wasserproduktivität zu ermitteln und andererseits den Beitrag der Tierhaltung zu einer möglichen Wasserknappheit zu bewerten. In dieser kumulativen Dissertationen werden die Ergebnisse der ersten Anwendung dieser Leitlinien der FAO in landwirtschaftliche Betriebe in Brasilien vorgestellt. In referierten Fachzeitschriften wurden bereits drei Originalarbeiten veröffentlicht. Im Rahmen der drei Veröffentlichungen wurde die Wasserproduktivität wurde für 115 Betriebe (Schweine-, Geflügel- und Milchviehbetriebe) im Einzugsgebiet des Lajeado Tacongava in Südbrasilien berechnet, wobei die Auswirkungen der Viehzucht auf die Wasserknappheit bewertet wurden. Die Ergebnisse der ersten und zweiten bereits veröffentlichten Originalarbeiten zeigen den großen Einfluss von Futtermitteln auf die Wasserproduktivität tierischer Erzeugnisse. Die Ergebnisse unterstreichen daher die Notwendigkeit einer engen Zusammenarbeit zwischen Pflanzenproduktion und Tierhaltung. Die Niederschlagswasserproduktivität der Futterproduktion muss verbessert werden, um das Management der Tierernährung zu optimieren. Darüber kann eine höhere Wasserproduktivität der Tierhaltung insgesamt erreicht werden. In Milchviehbetrieben zeigen die Ergebnisse, dass die Wasserproduktivität direkt von den Indikatoren für eine höhere Milchproduktivität des Betriebs abhängt, unabhängig von der Art des Produktionssystems, und unterstreichen die Bedeutung der Bewertung dieses Indikators WP auf Betriebsebene. Die dritte Veröffentlichung standen die Umweltauswirkungen der Wassernutzung der Tierhaltung im Fokus. Die Bewertung der Auswirkungen der Wassernutzung ergab eine geringe Wasserknappheit im untersuchten Wassereinzugsgebiet. Die Wasserknappheit ist nicht alarmierend, selbst bei den Szenarien mit geringerer Verfügbarkeit von Wasser. Die Produktion von Schweinen wies den größten „Fußabdruck der Wasserknappheit“ im Wassereinzugsgebiet auf, gefolgt von der Milch- und Geflügelproduktion. Diese Dissertation trägt dazu bei, das Wissen über die Wasserflüsse, die Wasserproduktivität der Schweine- und Geflügelproduktion und die Milchproduktion in verschiedenen Produktionssystemen auf betrieblicher Ebene zu erweitern. Es sind die ersten Berechnungen der Wasserproduktivität dieser Tierproduktionssysteme in brasilianischen Betrieben und die erste Bewertung der Auswirkungen der Wasserknappheit in der Tierproduktion in einem brasilianischen Einzugsgebiet. Zudem wurde das Land Brasilien damit in die internationale wissenschaftliche Diskussion zu diesem Thema eingeführt. Die LEAP-Richtlinien der FAO wurden in dieser ersten Studie in Brasilien erfolgreich angewandt. Auf der Grundlage der Ergebnisse wird eine breite Anwendung der Leitlinien empfohlen, um die Berechnung von zuverlässigen und vergleichbaren Ergebnissen zu gewährleisten und die Entscheidungsfindung von Regierung, Wirtschaft und Gesellschaft im Hinblick auf eine resiliente und nachhaltige landwirtschaftliche Produktionssysteme zu unterstützen. / Water shortages caused by persistent and severe droughts and changes in rainfall patterns are expected to be more frequent and intense due to climate change, increasing water competition and posing food production at risk. Therefore, sustainable and resilient food systems are needed to meet the demand of a growing population. Plant production and animal husbandry account for 72% of the water withdrawn worldwide. Most water consumed in livestock production is for animal feed production. Water is also needed to provide drinking water and to clean and cool the stables. In this context, increasing agriculture and livestock water productivity (WP) is crucial, along with integrated management and governance of water resources. WP describes the ratio of output (e.g. kg milk) to water input (e.g. m³ evapotranspiration). Water input includes direct (e.g. water intake) and indirect (e.g., water for purchased feed) water use. WP calculations are used primarily in evaluating agricultural measures to improve rainfall and technical WP in livestock and crop production. Consistent methods are needed to increase WP and also to reduce the water-related environmental impact of livestock systems. Recently, the Food and Agriculture Organization of the United Nations (FAO), through the Livestock Environmental Assessment and Performance (LEAP) Partnership, launched reference guidelines for assessing water use in livestock production systems and supply chains. The FAO LEAP guidelines aim to understand the water flows on a farm scale and evaluate the contribution of livestock activities to water scarcity, supporting the identification of opportunities to reduce the potential water use impacts in this sector. This cumulative thesis presents the results of the first application of the FAO LEAP guidelines on farms located in Brazil. Three original publications were published in peer-reviewed journals. The WP was calculated based on primary data collected on 115 farms (pig, poultry and dairy) located within the Lajeado Tacongava watershed in southern Brazil, where the water scarcity impact associated with livestock production was assessed. The results of the first two original papers published show the high influence of feed production on the WP of animal products. Therefore, the results emphasize the need for close cooperation between feed production and livestock production to improve WP. Rainfall WP of feed production can be improved to optimize animal nutrition management. In addition, higher livestock WP can be achieved. In dairy farms, results indicate that WP is directly dependent on dairy productivity indicators of the farm, regardless the type of production system, and reinforce the importance of assessing this indicator on a farm scale. In the third publication, the environmental impact of water use in livestock production was investigated. The water scarcity impact assessment demonstrated a low water scarcity in the watershed and it is not alarming even in the driest water flow scenarios. Pig production presented the highest water scarcity footprint in the watershed, followed by dairy farming and poultry production. This dissertation contributes to the advancement of knowledge on the water flows, WP of pig, poultry and milk produced under different production systems on farm scale, which are the first WP benchmarks for these animal production systems in Brazilian farms. It also introduced Brazil to the international scientific discussion on this topic. Some suggestions of potential improvements for the guidelines are presented in this study. The FAO LEAP guidelines were successfully applied in its first study in Brazil. Based on the results of this study, the guidelines’ widespread use is recommended to ensure reliable and comparable results to support government, business and society decision-making toward a more resilient and sustainable food supply chain.

South Africa is a water-scarce country and receives less rainfall than the average rainfall of the World. As population increases, and development calls for increased allocation of ground water and surface water for the domestic, agriculture and industrial sectors, the pressure on water resources intensifies. This is exacerbated by the wastages that occur in schools and homes. Conservation of water by all consumers is essential. The study attempts to identify practices that lead to wastage of water and indicate strategies for the reduction of water wastage and conservation strategy. / Educational Studies / M.Ed. (Environmental Education)

Many parts of the world, but South Africa specifically, are facing a water crisis, not only because of the scarcity of water, but also the quality of the water that is available. Companies are the primary users of water and can therefore have the most significant impact on saving water. It is thus imperative to determine how companies are measuring, managing, engaging with their stakeholders and disclosing water-related risks in their businesses. This study was conducted on the premise that South African companies have not as yet grasped the seriousness of the water crisis. Thirty JSE-listed companies classified as being water intensive were selected for the study. Their sustainability/integrated/annual reports for 2011 and 2013 were downloaded from the internet and analysed to determine if and how they were mitigating their water-related risks. The Ceres Aqua Gauge™ was used as the framework for this study. It was established during the analysis of the selected companies’ reports that, with the exception of food producers and food retailers, the companies had grasped the seriousness of the water crisis. One area of particular concern that was evident in all the companies was the lack of attention directed towards supply chain water management. Companies need to address water risks in their supply chain, and to also turn the water crisis from a threat into an opportunity. Investors need to engage with and put pressure on companies to improve their water management practices. / Business Management / M. Ph. Accounting Sciences (Management Accounting)

Wasser ist eine der wichtigsten Ressourcen. Jedoch schätzt man, dass sich das globale Wasserdefizit schon im Jahr 2030 auf ca. 40 Prozent belaufen wird. Klimawandel, veränderte Lebensweisen, und Bevölkerungswachstum verstärken das Nachfrage-Angebot-Defizit. Als Konsequenz leiden immer mehr Regionen unter Wasserknappheit. Eine reduzierte Wassernachfrage bedingt durch verstärktes Wassersparen kann das Problem verringern. Das Ziel dieser Dissertation ist es daher, zu einem besseren Verständnis der sozio-demographischen und psychologischen Determinanten von Wassersparverhalten beizutragen. Basierend auf drei Datensätzen aus Deutschland und Jordanien wurden die verschiedenen Facetten von Wassersparverhalten und deren Determinanten beleuchtet. Das Verhältnis zwischen Wassersparen und Umwelteinstellung, einem latenten Konstrukt, das kooperative, prosoziale und sogar moralische Tendenzen widerspiegelt, wurde konzeptionell untersucht. Zusätzlich wurde Wassersparen in Deutschland als ein Repräsentant für moralisches Verhalten verwendet. In diesem Zusammenhang wurden Umwelteinstellung und der Persönlichkeitsfaktor Ehrlichkeit-Bescheidenheit auf ihr Vermögen hin verglichen, moralisches Verhalten vorherzusehen. Eine ausführliche Analyse zur Bewertung einer Kampagne zur Förderung des Wassersparbewusstseins hat detaillierte Informationen zu ihren tatsächlichen Effekten gezeigt. Eine weitere Analyse hat sich auf die Determinanten von Wassersparverhalten in Jordanien konzentriert. Die Ergebnisse zeigen, dass Wassersparverhalten nicht durch Alter, Bildungsgrad und Einkommen beeinflusst wird, sondern eher durch die Ausprägung der Umwelteinstellung. Diese Dissertation liefert wertvolle Informationen für Forscher und Politiker. Die detaillierte Untersuchung von verschiedenen Wasserspardeterminanten birgt großes Potenzial für ein verbessertes Wassermanagement. / Water is one of the most important resources. However, the global water deficit was estimated to reach about 40% by 2030. Climate change, changing lifestyles, and population growth increase the supply and demand gap further. As a consequence, more and more regions experience water scarcity. In that context, reduced household water demand due to enhanced water conservation could alleviate the problem or, at least, reduce the pressure on water resources. Thus, this thesis aims to contribute to a better understanding of the socio-demographic and psychological determinants of water conservation behavior. Based on three distinct datasets from Germany and Jordan, the manifold facets of water conservation and its determinants were examined. From a conceptual perspective, the relationship between water conservation and environmental attitude, a latent construct representing cooperative, prosocial, and even moral tendencies, were investigated. Furthermore, water conservation in Germany was used as a proxy for moral behavior. In that respect, environmental attitude and the personality factor Honesty-Humility were compared in order to determine, which factor constitutes the better predictor of moral behavior. Using original data from Jordan, a comprehensive impact evaluation of a water conservation awareness campaign revealed detailed information on its actual effects. Another analysis focused on a wide variety of water conservation determinants in Jordan. The results indicate that water conservation does not differ with respect to age, education, and income, but rather with different levels of environmental attitude. This thesis provides valuable information for researchers and policy makers alike. The detailed examination of various water conservation determinants offer a great potential for an improved management of household water demand.

South Africa is a water-scarce country and receives less rainfall than the average rainfall of the World. As population increases, and development calls for increased allocation of ground water and surface water for the domestic, agriculture and industrial sectors, the pressure on water resources intensifies. This is exacerbated by the wastages that occur in schools and homes. Conservation of water by all consumers is essential. The study attempts to identify practices that lead to wastage of water and indicate strategies for the reduction of water wastage and conservation strategy. / Educational Studies / M.Ed. (Environmental Education)

Many parts of the world, but South Africa specifically, are facing a water crisis, not only because of the scarcity of water, but also the quality of the water that is available. Companies are the primary users of water and can therefore have the most significant impact on saving water. It is thus imperative to determine how companies are measuring, managing, engaging with their stakeholders and disclosing water-related risks in their businesses. This study was conducted on the premise that South African companies have not as yet grasped the seriousness of the water crisis. Thirty JSE-listed companies classified as being water intensive were selected for the study. Their sustainability/integrated/annual reports for 2011 and 2013 were downloaded from the internet and analysed to determine if and how they were mitigating their water-related risks. The Ceres Aqua Gauge™ was used as the framework for this study. It was established during the analysis of the selected companies’ reports that, with the exception of food producers and food retailers, the companies had grasped the seriousness of the water crisis. One area of particular concern that was evident in all the companies was the lack of attention directed towards supply chain water management. Companies need to address water risks in their supply chain, and to also turn the water crisis from a threat into an opportunity. Investors need to engage with and put pressure on companies to improve their water management practices. / Business Management / M. Ph. Accounting Sciences (Management Accounting)

MPH / Department of Public Health

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

MENVSC / Department of Geography and Geo-Information Sciences / Many rural communities of South Africa are living without adequate water supplies mainly due to historical lack of infrastructure and effective water reticulation systems. Day to day challenges of accessing water from distant boreholes and rivers are a reality particularly for women and children in rural Limpopo. This study investigates the nature and extent of water supply problems and how communities are living without adequate water in three rural communities of Greater-Giyani Local Municipality in South Africa. The study area lies in a semi-arid region which regularly experiences climate extremes such as droughts and floods which can reduce the ability of the municipality to supply water. Primary data was collected through questionnaires, key informant interviews and field observations while population, climate and hydrological data are also analyzed. A mixed methods research design was employed using qualitative methods such as content analysis whilst quantitative methods were dominated by time series analysis techniques and online interactive climate platforms such as the Climate Engine. It was found that households, schools and clinics in the study area rely mainly on boreholes for water supply but sometimes rivers supply those living nearby. An incomplete and poor water reticulation system coupled with erratic and shortening summer rainfall seasons are some of the major causes of water shortages in the study area. In order to cope with inadequate water, community members and public institutions in the study area have drilled boreholes and the sustainability of groundwater in the area is not well established. During summer, most households and institutions practise rainwater harvesting while a few resort to purchasing water from vendors. Despite these challenges which are not well documented, it was concluded that most of the rural poor households and institutions in the study area are well adapted to cope with water scarcity in the short term, while being vulnerable in the long term due to population growth and climate change. The study recommends the need for government and municipalities to invest in water reticulation systems in the long term whilst providing water to affected rural communities through water tankers, drilling more boreholes and maintenance of existing ones. Lessons learnt from this study may be useful to other municipalities across South Africa that are grappling with challenges of water access and supply. / NRF

In this thesis, the potential to purify water utilizing waste heat from a unit which stores thermal energy and converts it to electricity is studied. The unit, called TES.POD, is developed by Azelio AB and is in this thesis used as a heat source to drive an air gap membrane distillation (AGMD) unit developed by Scarab Development AB. Heat from the TES.POD and ambient air temperature constitutes a temperature difference over a membrane used as a driving force to vaporize a part of the water that transfer through the membrane, and later condensates as clean distilled water as the contaminations stays in the hot stream of feed water. An analysis has been conducted to determine quasi-steady performance of the combined system for estimating the amount of purified water that can be supplied when the TES.POD unit is in peak electricity discharge mode. The 26 kW of waste heat accessible from the TES.POD is shown to enable two AGMD-modules producing purified water at a production of 7, 1l/h per unit having the feed water at 50°C and cooling water at 25°C. A correlation between the amount of waste heat and distilled water production is determined, as the TES.POD could be configured to produce less electricity and more waste heat at a higher temperature. The correlation showed that an 9% increase in cooling temperature, lead to an 30% increase in pure water output and a 33% decrease in electricity output. The results show that when implementing the two companies’ units together, a system that both provides electricity and distilled water is obtained. This is a system with a high demand, especially in off-grid areas with lack of both resources but with accessible renewable energy sources. Moreover, by using waste heat to purify water, it can also reduce the production cost compared to cases where conventional energy sources are used. The potential revenue of the production was estimated to 673 790 SEK/year with an implementation cost of 93 861 SEK with yearly operational expenses estimated to 14 080 SEK/year. / I detta arbete undersöks möjligheten att rena vatten med spillvärme från ett system vilket lagrar termisk energi och av den producerar elektricitet, när det behövs. Systemet är utvecklat av Azelio AB och har produktnamnet TES.POD. Vattendestillationen utförs med en så kallad air gap membrane distillation (AGMD) modul, utvecklad av Scarab Development AB. Värmen från TES.POD och omgivningstemperaturen utgör, i AGMD-modulen, en temperaturdifferens vilken i sin tur skapar en partielltryckskillnad över membranet. Denna partielltryckskillnad låter en del av det förorenade vattnet som flödar i AGMD-modulen att förångas och passera genom membranet. Föroreningarna stannar kvar i det strömmande vattnet och ångan kondenserar som renat vatten.  Arbetet visar att de 26kW som finns att tillgå i form av spillvärme är tillräckligt för att driva två AGMD-moduler att producera 7,1 l/h destillerat vatten per modul. Detta är under förutsättningar att det förorenade vattnet är 50°C och kylvattnet är 25°C. I rapporten återfinns också ett samband mellan mängden spillvärme och produktionen av destillerat vatten, eftersom TES.POD kan konfigureras till att producera spillvärme vid en högre temperatur. Sambandet visade på att 9% ökning av spillvärmens temperatur motsvarar 30% ökning i produktionen av destillerat vatten och en minskad elektricitetsproduktion på 33%.  Resultatet visar på att integrationen av dessa två produkter bildar ett system som både producerar rent vatten och elektricitet när så önskas. Detta system har till synes en stor efterfrågan, speciellt i områden utanför fast el- och vattennätverk men med goda förnyelsebara energikällor. Dessutom, eftersom vattendestillationen sker med spillvärme, kan produktionskostnaderna vara lägre än då konventionella energikällor används. Den potentiella inkomsten från produktionen estimeras till 673 790 SEK/year med en inköpskostnad om 93 861 SEK samt årliga omkostnader om 14 080 SEK/year.