This research used an Integrated Water Resource Management approach to investigate how Water Demand Management (WDM) measures at government, utility and end-user levels could contribute to providing sustainable water supply to Bahrain, which is in an arid to semiarid region. The main driver for this research was the supply-driven orientation favoured by policy makers and practitioners in Bahrain with little consideration for demand management. This leads to a high estimated gross per capita consumption 525 l/c/d as of 2010. There was also a need to investigate the institutional environment for managing water resources and delivering sustainable water supply to Bahrain. The research adopted a case study methodology which included qualitative analysis of interviews and documents from the water authority, and quantitative analysis of questionnaire surveys and pilot studies. The research adopted a cross-sectional approach to the analysis of activities associated with WDM practice in Bahrain. All findings and conclusions were evaluated/validated using surveys distributed to water experts and customers. Based on their feedback, findings and conclusions were revised. The main finding of this research was that the tariff is highly subsidized by the government and there is no encouragement for water savings. The low tariff leads to low revenue which in turn affects the budget allocated to the relevant departments and units at the Electricity and Water Authority (EWA). This impacts negatively on their activities. It was found that there is no effective strategy for integrated water resources management; there is a high level of Non Revenue Water (NRW) (38%); and limited reuse of grey water and water use saving devices. In addition there is a lack of public awareness and understanding of the benefits of WDM among all levels of society including professionals and water supply providers. The research concluded that improving water use efficiency in Bahrain should be a priority due to the current high water supply costs. There is a need for proper legislation that enforces the use of WDM; establishment of a national WDM committee with the Water Resources Directorate, and for water resource professionals to follow WDM oriented policies. The research proposed six areas to be further investigated to achieve more efficient use of water: (a) Water tariff reform to recover full water supply costs; (b) institutional reform through activating and enforcing Water Resources Council roles; (c) promoting public awareness about WDM and its benefits; (d) reducing non revenue water; (e) applying positive economic sliding scale incentives for customers who reduce their water consumption.

Miami-Dade County implemented a series of water conservation programs, which included rebate/exchange incentives to encourage the use of high efficiency aerators (AR), showerheads (SH), toilets (HET) and clothes washers (HEW), to respond to the environmental sustainability issue in urban areas. This study first used panel data analysis of water consumption to evaluate the performance and actual water savings of individual programs. Integrated water demand model has also been developed for incorporating property’s physical characteristics into the water consumption profiles. Life cycle assessment (with emphasis on end-use stage in water system) of water intense appliances was conducted to determine the environmental impacts brought by each practice. Approximately 6 to 10 % of water has been saved in the first and second year of implementation of high efficiency appliances, and with continuing savings in the third and fourth years. Water savings (gallons per household per day) for water efficiency appliances were observed at 28 (11.1%) for SH, 34.7 (13.3%) for HET, and 39.7 (14.5%) for HEW. Furthermore, the estimated contributions of high efficiency appliances for reducing water demand in the integrated water demand model were between 5 and 19% (highest in the AR program). Results indicated that adoption of more than one type of water efficiency appliance could significantly reduce residential water demand. For the sustainable water management strategies, the appropriate water conservation rate was projected to be 1 to 2 million gallons per day (MGD) through 2030. With 2 MGD of water savings, the estimated per capita water use (GPCD) could be reduced from approximately 140 to 122 GPCD. Additional efforts are needed to reduce the water demand to US EPA’s “Water Sense” conservation levels of 70 GPCD by 2030. Life cycle assessment results showed that environmental impacts (water and energy demands and greenhouse gas emissions) from end-use and demand phases are most significant within the water system, particularly due to water heating (73% for clothes washer and 93% for showerhead). Estimations of optimal lifespan for appliances (8 to 21 years) implied that earlier replacement with efficiency models is encouraged in order to minimize the environmental impacts brought by current practice.

With an ever-increasing population and global warming, fresh water resources are nearing depletion resulting in a global water crisis. As a consequence, cases of drought have been reported worldwide especially in sub-Saharan Africa. In addition to climate change, urbanisation adds strain to infrastructure as well as water supply and the management of water resources. As a result, most developing countries are faced with a water management challenge. There is thus a need for a paradigm shift towards an Integrated Water Management (IWM) approach. Worldwide, countries have responded to the Integrated Urban Water Management (IUWM) concept through the implementation of various management strategies; with Water Sensitive Urban Design (WSUD) emerging from Australia. Some closely allied management strategies in response to IUWM emerged in the USA as Low-Impact Development (LID), in the UK as Sustainable Drainage Systems (SuDS), and in New Zealand as Low-Impact Urban Design and Development (LIUDD). Namibia is situated along the south-west coast of Africa and is considered the driest country in sub-Saharan Africa. It is characterised by a semi-arid environment, with more than 80% covered by desert or semi-desert. The country is regularly afflicted by drought and has fluctuating and unreliable rainfall patterns, often accompanied by high evaporation rates. The City of Windhoek, as the capital city, the biggest municipality and also the largest densely populated town in Namibia, is faced with an ever-increasing shortage of water for its inhabitants. For close to 50 years, the water scarcity situation has led to direct waste water reclamation for potable re-use in Windhoek. Other measures implemented by the City of Windhoek (CoW) towards IUWM include Water Demand Management (WDM), Managed Aquifer Recharge (MAR) and Water Conservation (WC). In order for Windhoek to transform into a Water Sensitive City, the implementation of WSUD is imperative. Although the CoW has implemented measures towards IUWM, more options still need to be explored in order to contribute to IUWM processes and to ultimately become a Water Sensitive City. This research was aimed at conducting a comprehensive review of existing WSUD practices within the CoW and identifying gaps pertaining to WSUD implementation. The research confirmed, via a review of relevant literature, that the implementation of WSUD mainly flourishes when documented policies and regulations drive implementation. To review WSUD implementation in the CoW, this study followed a qualitative research approach by gathering data via online questionnaires using the SurveyMonkey platform. To validate the survey outcomes, structured interviews were conducted with selected survey participants to gain more insight into the outcomes. For the data collection, the study targeted a sample of managers and specialists from the three departments within the CoW that deal with urban infrastructure design and planning. A 72% response rate was achieved. The study revealed that there was a general understanding and knowledge of WSUD concepts among all the CoW stakeholders involved in water management, planning and design. This was mostly due to their academic knowledge and sometimes via exposure to existing WSUD practices within the city. Water Demand Management, Water Recycling, and Voluntary Green Roofs and Rainwater Harvesting were identified as existing WSUD options currently practised within the CoW. The study identified lack of capacity, lack of knowledge, lack of management support, a fragmented approach, the absence of policies and legislation, and no perceived financial benefits as barriers to WSUD implementation within the CoW. Based on the above findings, the study recommended that the City of Windhoek address existing barriers to WSUD implementation, increase awareness of WSUD within the city, secure government funding and apply for carbon credits to upscale the implementation of WSUD.

This paper analyzes the demand for water in case of a multiple-part tariff in Denton, Texas. The model used is developed from Billing & Agthe's model by using the following variables: marginal price, difference variable, tax assessed value, lot size, house size, temperature and rainfall.. The results indicate that temperature has the greatest effect on water demand, since this area is considered to be a very warm area. Also, marginal price seems to have a strong effect on water consumption indicating that customer is well-informed to a change in rate schedule. This test supports the original idea of the previous articles that the coefficient on difference variable and that on income should have the opposite sign. However, this test can not prove that those coefficients should be equal in magnitude, since the proxy of the income variable can not represent the individual monthly income. In addition, this article introduces another variable which can be a proxy of outdoor water use. That is lot size showing the effect on water demand. The last variable used in the model, house size,does not have much effect on water demand and is dropped out in the final model.

No description available.

The Department of Arequipa, in Peru, is a region with limited water resources making freshwater management critical and requiring the development of water-demand models, which can be valuable tools for policymakers. This study developed a monthly agricultural water-demand mapping algorithm for the agricultural districts surrounding the city of Arequipa. It was accomplished by:(1) developing a ground-reference data collection method;(2) creating a crop mapping algorithm, which incorporates supervised classification methods, as well as spatial-and temporal-consistency correction methods to create crop maps out of high resolution (~3 m) PlanetScope satellite images; (3) integrating a crop growth-stage prediction algorithm for the crop maps and; (4) applying an algorithm for the estimation of the agricultural-water-demand maps using the results of steps 2 and 3, local climate data, and an irrigation demand estimation tool. The crop mapping algorithm was shown to create maps with acceptable accuracy, with 5 out of 6 months with available data having mean monthly classification accuracies of 69% to 77%for those classes which had available data. Growth stage predictions had mean absolute prediction errors of 0.55 to 0.69 months in 5 out of 6 months.The6th month (the first with ground reference data collection) had a mean absolute prediction error of 0.90 months because it lacked prior month information to correctly identify planting month. Water demand maps were produced with high spatial (3.0m) and temporal (monthly) resolution, allowing for a detailed look at local agricultural water demands. This study provides a framework for future large-scale agricultural-water demand mapping for the Department of Arequipa and similar regions around the world.

Der Gegenstand des Projektes SAPHIR war die Untersuchung von Trockenstress, Wasserproduktivität und Bewässerungsbedarf landwirtschaftlicher und gemüsebaulicher Nutzpflanzen mit Hilfe von Bewässerungsexperimenten und Simulationswerkzeugen (virtuelles Feld). Das Hauptziel war die Bereitstellung relevanter Informationen, Schlußfolgerungen und Handlungsoptionen für wesentliche Akteure (Landwirte und Entscheidungsträger auf regionaler Ebene) aus der sächsischen Landwirtschaft. Einen einfachen Zugang zu den entwickelten Werkzeugen und Ergebnissen liefert ein webbasiertes Entscheidungshilfesystem mit maßgeschneiderten Schnittstellen für die verschiedenen Akteure, dass die Ermittlung der Bewässerungswürdigkeit beliebiger Standorte und angepasster Anbaumuster für Sachsen für gegenwärtige und zukünftige Klimabedingungen ermöglicht. Die Bestimmung der dafür wichtigen Datengrundlagen, nämlich kulturspezifische Ertragskurven erfolgte auf zwei Wegen: durch konkrete Feldversuche sowie simulationsbasierte Optimierung. Durch die Verwendung von prognostischen Simulationsmodellen ist die Übertragung der Ergebnisse auf andere klimatische Standorte möglich und wurde wird zur Zeit für die Vereinigte Arabische Emirate und den Oman erprobt. Im Rahmen von SAPHIR fand eine intensive Qualifizierung der Nachwuchsforscher statt. Dies umfaßte nicht nur eine umfassende Vermittlung von Spezialwissen über Bewässerungslandwirtschaft inklusive der Teilkomponenten Messung, Modellierung, Analyse und Darstellung sondern auch der Erwerb von Fähigkeiten in Projektmanagement und Kommunikation für eine erfolgreiche Zusammenarbeit innerhalb der interdisziplinär zusammengesetzten Forschergruppe. Die von uns durchgeführten Arbeiten erfolgten in zwei grundsätzlichen Richtungen. Zum einen entwickelten wir die Werkzeuge zur Entscheidungshilfe in der Reihenfolge: experimentelle Untersuchung → Modellierung und Simulation des Bewässerungssystems → simulationsbasierte Optimierung des Bewässerungssystems → Mikro- und Makroökonomische Bewertung und Optimierung. Zum anderen wurden die Arbeiten auf unterschiedlichen räumlichen Skalen durchgeführt: Mikroskala, Feldskala, Betriebsebene sowie regionale (Meso-) Skala.:1 Ziele/Teilziele des Projektes 1 1.1 Bewässerungsversuche und Übertragung von Ergebnissen 1 1.2 Informationserweiterung durch Modellierung 1 2 Regionale Einordnung 3 3 Angaben zur Teilnehmerstruktur 5 4 Durchgeführte Arbeiten 7 4.1 Feld- und Vegetationshallenversuche 7 4.1.1 F2012 Durchführung von spezifischen Feldversuchen 2012 7 4.1.2 F2013 Durchführung von spezifischen Feldversuchen 2013 7 4.1.3 F2014 Durchführung von spezifischen Feldversuchen 2014 7 4.1.4 G2014 Untersuchungen zu Unterschieden in der Strahlungsexposition bei Containerexperimenten in einer Vegetationshalle im Vergleich zu Feld- beständen 7 4.2 Arbeitspaket A1 8 4.2.1 A1.1 Sichtung und Analyse vorhandener Daten (Klima, Boden, Pflanzen, Bewirtschaftung) 8 4.2.2 A1.2 Modellwahl (Pflanzenwachstum, Bodenwasserhaushalt) 9 4.2.3 A1.3 Auswahl relevanter Leitböden und Kulturpflanzen 9 4.2.4 A1.4 Generierung langjähriger Klimazeitreihen 10 4.3 Arbeitspaket A2 10 4.3.1 A2.1 Modellerstellung und -kalibrierung 10 4.3.2 A2.2 Umfangreiche Simulations- und Optimierungsrechnungen10 4.3.3 A2.3 Optimales Bewässerungsmanagement 11 4.3.4 A2.4 Kosten-Nutzen-Analysen 11 4.4 Arbeitspaket A3 11 4.4.1 A3.1 Anwendung prognostischer Klimaszenarienrechnungen 11 4.4.2 A3.2 Erstellung von stochastischen Ertragsfunktionen 12 4.4.3 A3.2 Erstellung von stochastischen Bodenkennfunktionen 12 4.4.4 A3.3 Erstellung des Entscheidungshilfesystems 12 5 Methoden 13 5.1 Messexperimente Freising 13 5.1.1 Bewässerungsversuche F2013 13 5.1.2 Bewässerungsversuche F2014 14 5.1.3 Strahlungsmessungen F2014 16 5.2 Messexperimente Brandis 18 5.3 Messexperimente Pillnitz 21 5.4 Modellierung auf der Mikroskala 25 5.4.1 Einfluss des Wurzelmodells auf den Wurzelwasserentzug 25 5.4.2 Lysimetermodell 27 5.5 Modellierung auf der Feldskala 29 5.5.1 Klimadaten in Dresden Pillnitz 30 5.5.2 Modellanalyse und Modellkalibrierung 31 5.5.3 Modellkalibrierung für den Standort Pillnitz 34 5.5.4 Stochastische Ertragsfunktionen – SCWPF 35 5.6 Modellierung auf der Regionalskala 36 5.6.1 Klimadaten 36 5.6.2 Regionale Pflanzenmodellierung 37 5.6.3 Ableitung des Wasserdargebotes 39 5.7 Agrarökonomische Bewertung 41 5.7.1 Spline-Interpolation der SCWPF 42 5.7.2 Feldskala 44 5.7.3 Regionalskala 45 5.7.4 Optimierung 46 5.8 Prototypische Umsetzung des Entscheidungshilfesystems 49 5.8.1 Konzept des Entscheidungshilfesystems 49 5.8.2 IT-Konzept 50 5.8.3 Software 50 6 Ergebnisse und deren Dokumentation 53 6.1 Messexperimente Freising 53 6.2 Feldexperimente in Brandis 59 6.3 Feldexperimente in Pillnitz 62 6.4 Auswertung von Klimadaten 67 6.4.1 Projizierte Niederschlagsänderung 67 6.4.2 Trockenheitsindizes – Methode für eine erste Gefährdungsanalyse 67 6.4.3 Beispielhafte Entwicklung von Temperatur und Niederschlag 69 6.5 Einfluss des Wurzelmodells auf den Wurzelwasserentzug 70 6.6 Modellierungsergebnisse auf der Feldskala 76 6.7 Stochastische Ertragsfunktion – dateninduzierte Unsicherheit 79 6.8 Modellierungsergebnisse auf der Regionalskala 80 6.8.1 Ertrag und Wasserbedarf 80 6.8.2 Wasserdargebot 83 6.8.3 Gegenüberstellung von Wasserdargebot und -bedarf 83 6.8.4 Erträge weiterer Kulturen 85 6.8.5 Wasserproduktivitäten 87 6.9 Agrarökonomie 87 6.10 Entscheidungshilfesystem 90 6.10.1 Restriktionen 94 6.11 Dokumentation der Ergebnisse 96 7 Nachhaltigkeit 99 7.1 Technologieentwicklung und -transfer 99 7.2 Persönliche Qualifikation der Mitarbeiter 99 A Anhang: Durchgeführte Arbeiten 103 B Anhang: Ergebnisse 105 B.1 Messexperimente 105 B.2 Ertragssicherheit 106 B.3 Wasserproduktivität 111 B.4 Entscheidungshilfesystem 116 Abbildungsverzeichnis 119 Tabellenverzeichnis 125 Literaturverzeichnis 127

No description available.

The occurrence of water crises in many parts of the world raises the need to consider more efficient and sustainable consumption of water resources. As such, many cities have prioritised water demand management strategies, which are based on price and non-price mechanisms. The literature shows no consensus as to which of these measures are most effective for managing residential water demand. To understand the impact and effectiveness of these mechanisms, there is a need to understand how people respond to them. This requires understanding materials, meanings and competences (skills and know how) that people have, which constitute elements of social practice. In 2017 and 2018, the City of Cape Town (CoCT) ramped up their price and non-price mechanisms to encourage people to save water in response to a severe drought. These mechanisms included water restrictions, increased water tariffs, and the Day Zero communication campaign. However, little is known about how effective these measures were at encouraging people to save water. There is no clear documentation of how the public understands, interprets and incorporates these mechanisms into their own household water use practices. This study explores the impacts and effectiveness of the City of Cape Town’s price and non-price mechanisms on household water use practices during the water crisis. Using information obtained through semi-structured interviews with 20 individuals living in houses where they paid their water bills, a version of social practice theory is used as a lens to understand how respondents interpreted and responded to these mechanisms when it comes to residential water use practices. This allows for an assessment of which of the CoCT’s actions are more effective in achieving sustainable water use practices. Results show that price mechanisms (water tariffs) were considered to be ineffective and did not encourage people to save water. Non-price mechanisms (water restrictions and Day Zero communication campaign) were seen as having more impact on respondents, encouraging water conservation behaviour; especially when it comes to household indoor water use activities related to hygiene. Compared to other studies which have used estimates for the water demand function, this study conducted interviews directly with households on the impact of the mechanisms. This enabled this study to explain how and why household water use practices change in response to these measures. Such qualitative information is important and contributes to a field that often uses quantitative data to suggest whether price or non-price mechanisms are effective.

No description available.