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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.
261

Insamling, rening och användning av vatten i den hållbara hemträdgården.

Wedrén, Malin January 2009 (has links)
Utan vatten inget liv. Människor är beroende av rent vatten för sin överlevnad. I många länder orsakar idag bristen på rent vatten sjukdomar och för tidig död. Världens problem med sötvatten i form av brist och svåra föroreningar orsakade av människan kan te sig kolossala. Befolkningsökning och ändrade levnadssätt påverkar. Industrier och jordbruk har stor påverkan men också den enskilda människans vattenanvändning har betydelse.   I Sverige tycks den allmänna inställningen vara att vi inte har ett problem med vårt användande av vatten. Men vid en närmare undersökning av vårt innanhav Östersjöns problem med exempelvis övergödning och syrebrist och utsläppen av näringsämnen ifrån våra enskilda avlopp kan man ställa sig frågande. Även svenskens nyttjande av grundvattenreserver kan te sig olämpligt utifrån ett ekologiskt hållbart perspektiv. Att sedan detta vatten renas till dricksvattenkvalitet för att sedermera användas till att vattna fuktälskande växter som är planterade i gassande sol i en sandig torr jord kan vara förbryllande. Medvetenhet utifrån det lilla perspektivet, till exempel den svenska hemträdgården, kan vara åskådligt. Samtidigt kan det kanske också bidra till en i framtiden miljövänligare politik där målet är att rent sötvattnen skall finnas tillgängligt för alla i ett långt perspektiv.   I denna litteraturstudie, möjligheten till en rationell vattenanvändning i den privata hemträdgården ur ett ekologiskt hållbart perspektiv. Flertalet olika metoder att hushålla med vatten och att tillvarata, rena och använda sig av nederbörd och gråvatten belyses. Resultatet är indelat i två delar; hushållning och rening. I den första redogörs på vilka sätt en effektivisering av vattenanvändandet kan gå till. Lättast och effektivast görs detta genom att dra ner på förbrukningen. Detta går enkelt att göra med några få tekniker. Till exempel att bättra på jordstruktur med organisktmaterial, att placera växter på platser som liknar deras naturliga habitat, minska avdunstning och forma platsen så att nederbörd kan ledas dit den behövs. Att se över hur extrabevattning ska tillämpas på effektivast sätt samt vilken vattenkälla detta vatten kommer ifrån tillhör också detta hushållande stycke. I den andra delen redogörs för olika metoder som kan tillämpas i en trädgård för att rena grå- och dagvatten så att trädgårdens naturliga potential till att vara en del av jordens naturliga kretslopp främjas. Lättast görs detta genom en begränsning av föroreningar redan vid deras källa. Därefter kan infiltrationsytor, infiltrationsplanteringar, biodiken, gröna tak, dammar, konstruerade våtmarker, rotzoner, UV-ljus och aquakulturer vara mer eller mindre användbara metoder som kan tillämpas i hemträdgården.   Vattenfrågan bör klarläggas redan vid planeringen av byggnader och trädgård. Varje tomt måste sättas in i sitt sammanhang då dessa unika med speciella förutsättningar och problem. Hemträdgården är en utmärkt plats för experiment och utvecklingsarbete av ett hållbart vattenanvändande. / Without water there would be no life on earth. People depend of clean water for their survival. Today in many countries the lack of clean water is causing disease and premature death. World problems with fresh water in the form of shortage and severe pollution caused by humans may seem colossal. Industries and agriculture have a major impact but also the individual’s water-use has consequences.   In Sweden the public opinion seems to be that we do not have a problem with our use of water. But with a closer look on facts that is not the case. For example our inland sea, Östersjön, and our contribution to its problems with euthrophication, lack of oxygen with the spillage of nutrients from the sewers and agriculture. Also the Swedish use of ground water may seem inappropriate in an ecological sustainable perspective. What is even more puzzling is that this water gets cleaned to a drinking water quality and then gets used for watering plants in the garden or to wash the car. Consciousness from the small perspective (as the Swedish private garden) can contribute to a future environmentally friendly politic that will lead to a sustainable water-use in a long perspective.     With this paper I would like to demonstrate, in a literature study, the possibility of a rational water-use in the private home garden from an ecological sustainable perspective.  Different methods of economising the water-use, gathering and cleaning stormwater and greywater will be illustrated. The result part will be divided into two parts; economization of water and cleaning of water.   The first part describes the ways in which an efficiency of water-use can be preceded. The easiest way this is done is to cut down the consumption of water. This can easily be done with a few techniques. For example to improve the soil structure with organic material, placing of plants in places that resemble their natural habitat, reduction of evaporation and shaping pf the site so that precipitation can be managed where it is needed. Also to in which way irrigation is applied in the most efficient way and from which source this water is taken is presented in this part. The second part describes different methods of cleaning grey- and stormwater so the home garden’s natural potential to be a part of the earth’s natural rhythm is promoted. Most easily this is done by stopping the pollution at the source. After that infiltration areas, bioswales, green roofs, ponds, constructed wetlands, reed beds, UV light and aquacultures can be more or less potential methods to be applied in the home garden.   Water issues should be clarified already at the design process with homes and gardens. Each plot and garden is unique with its particular conditions and problems. Therefore needs every case to be seen in its particular context in order to obtain the optimal solution for that particular place.The home garden is a suitable place for experimental development of a sustainable water-use.
262

The effect of pulse crops on arbuscula mycorrhizal fungi in a durum-based cropping system

Fraser, Tandra 07 April 2008 (has links)
Pulses are an important component in crop rotations in the semiarid Brown soil zone of southern Saskatchewan, Canada. Besides their capability to fix nitrogen, pulse crops establish a strong symbiotic relationship with arbuscular mycorrhizal fungi (AMF), which have been shown to increase nutrient and water uptake through hyphal extensions in the soil. Incorporating strongly mycorrhizal crops in a rotation may increase inoculum levels in the soil and benefit the growth of a subsequent crop. The objective of this study was to determine if AMF potential and colonization of a durum crop is significantly affected by cropping history and to assess the impact of pulses in crop rotations on the abundance and diversity of AMF communities in the soil. In 2004 and 2005, soil, plant, and root samples were taken on Triticum turgidum L. (durum) with preceding crops of Pisum sativum L. (pea), Lens culinaris Medik (lentil), Cicer arietinum L. (chickpea), Brassica napus L. (canola) or Triticum turgidum L. (durum). Although there were few differences in soil N and P levels, previous crop had a significant effect (p<0.05) on durum yields in both years. A previous crop of pea was associated with the highest yields, while the durum monocultures were lowest. Arbuscular mycorrhizal potential and colonization were significantly affected (p<0.05) by cropping history, but not consistently as a result of inclusion of a pulse crop. Phospholipid and neutralipid fatty acids (PLFA/NLFA) were completed to analyse the relative abundance of AMF (C16:1ù5), saprophytic fungi (C18:2ù6), and bacteria in the soil. The effect of treatment on the abundance of AMF, saprotrophic fungi and bacteria were not significant (p<0.05), but the changes over time were. These results demonstrate that although previous crop may play a role in microbial community structure, it is not the only influencing factor.
263

A comparative assessment of communal water supply and self supply models for sustainable rural water supplies : a case study of Luapula, Zambia

Kumamaru, Koji January 2011 (has links)
Over the last couple of decades, a significant amount of research has been carried out on rural water supplies in developing countries, and have identified the fact that the communal water supply model is not sustainable everywhere, especially in sparsely populated rural areas; factors obstructing sustainability include lack of spare parts, management systems and private/public capacity. Despite their enormous contribution to the water sector, the extant studies stay within the subsidized communal water supply and capacity building, post construction support or management system. In other words, very few studies have been done into household (private) level water supply. The Self Supply model is an approach which provides support to households/communities to complement their efforts and accelerate sustainable access to safe water incrementally through improvement to traditional water sources (hand dug wells) by putting in their own investment. The Self Supply model may give significant benefits for sustainable safe water supplies, especially in sparsely populated rural areas, in comparison with the communal water supply though to date there has been little monitoring and systematic analysis of what impact these changes have made at the grassroots level. The standpoint of this study is pragmatic, and herein, mixing quantitative and qualitative methods was justified in order to design the research methodologies. The research was conducted in the Luapula Province of Zambia using a concurrent triangulation strategy to offset the weakness inherent within one method with the strengths of the other. The data was collected through inventory and sanitary surveys, water quality testing, household surveys, document analyses, focus group discussions and key informant interviews to determine the most appropriate water supply model for safe, accessible, sustainable, cost-effective and acceptable water supplies for households in sparsely populated rural areas of Zambia. The principal argument of this study is that reliance only on a communal water supply model limits the achievement of increased sustainable access to a safe water supply; hence a Self Supply model is needed which does not compete with the communal models but works alongside them in sparsely populated rural areas of developing countries for the purpose of increasing access and achieving sustainability. It was strongly defended by the overall findings that a Self Supply model could significantly reduce the faecal contamination risk in water quality and deliver a higher per capita water use and better convenience of access than the communal model; however its reliability with respect to the water source drying up needs to be monitored. Further, this does not mean that the communal model is not sustainable anywhere, rather that it is important to build blocks for a sustainable environment to access safe water in a symbiotic way between the communal and Self Supply models under the condition that the government and NGOs/external support agencies overcome the temptation to provide a water supply to rural dwellers as a giveaway social service.
264

Evolutionary genetics and ecology of water use efficiency ([delta]¹³C) in Ipomopsis agregata and Arabidopsis thaliana

Kenney, Amanda Marie 31 January 2012 (has links)
My dissertation research investigates the genetic architecture and evolutionary significance of physiological variation in two wildflower species, Ipomopsis aggregata and Arabidopsis thaliana. In particular, my work focuses on water use efficiency (WUE), a critical physiological trait that dictates plant growth and performance in resource-limited environments. I used a combination of quantitative trait loci (QTL) mapping, field selection experiments, and classic quantitative genetics to investigate 1) the genetic architecture of water use efficiency and flowering time, 2) patterns of natural selection on water use efficiency, flowering time, and other ecological traits in I. aggregata, and 3) additive genetic variation, genetic correlations, and selection on water use efficiency, flowering time, and plasticity to drought in Arabidopsis thaliana. Using an Ipomopsis aggregata genetic mapping population, I identified four QTL underlying WUE, three QTL-QTL epistatic interactions, and evidence for a possible QTL x cytoplasmic interaction affecting WUE. I found a similar genetic architecture underlying flowering time, with four main effect QTLs that all adjacently localized to the same linkage groups as WUE, and three QTL-QTL epistatic interactions, which occur between the same chromosome pairs as the WUE interactions. The combined main and interactive effects explain 35% and 40% of the phenotypic variation in WUE and flowering time, respectively. The adjacent localization suggests a possible role for the evolution of co-inheritance or, if the true QTL positions actually overlap, a possible role for pleiotropy underlying the phenotypic correlation between WUE and flowering time. Additionally, these results suggest epistasis is a significant factor affecting phenotypic variation in nature. In a reciprocal transplant and water addition experiment, I demonstrated variable natural selection on WUE, flowering time, and nectar production in I. aggregata across elevation/habitat and differential water availability. At low elevation in the water addition treatment, natural selection favors early flowering and greater nectar sugar concentration, while dry conditions favor high WUE and early flowering time. At high elevation, where the growing season is shorter and drier, selection favors early flowering regardless of water addition. These results suggest natural selection on ecophysiological and floral traits varies with resource availability (e.g. water availability and pollinator visitation). Using data from a glasshouse experiment involving a global panel of accessions of Arabidopsis thaliana, I demonstrated strong positive genetic correlation between WUE and flowering time, as well as selection for low WUE and early flowering under experimental season-ending drought. Finally, I found significant genetic variation in plasticity as well as selection favoring greater WUE plasticity under drought, indicating plasticity to drought is adaptive in A. thaliana. / text
265

ARE PEOPLE RESPONSIVE TO WATER RATIONING POLICIES?

2015 September 1900 (has links)
It is difficult for policymakers to predict the behavior of people in response to a water rationing policy. The public may not necessarily behave as expected or in accordance with market rules or policy mandates. In this research, I will ask whether people were responsive to a summer 2011 City of Saskatoon legal restrictions to reduce their outdoor water consumption due to reduced capacity at the water treatment plant resulting from excessive solids in the river water. I will try to explore the policy response - which can be expressed as a reduction of outdoor water consumption in 2011 in response to the water mandate - while holding constant other factors, including environmental variables (temperature and rainfall), socio-economic factors (income and education level), lot size, and an annual downward trend in water consumption that appeared in many North American cities during the past two decades. Monthly water consumption data for the period from 2004 to 2012 for the City of Saskatoon were analyzed to detect if there is a policy response from the water mandate during June and July 2011. Regression analysis with water consumption as the dependent variable and lot size, temperature, rainfall, education index, income, consumption trend, and policy as independent variables was conducted to test whether there is a policy response in the Saskatoon water records, holding other factors relevant to water consumption constant. Results showed there was a statistically significant reduction in Saskatoon water consumption during June and July 2011 as a result of the water rationing mandate, with considerable variations through different neighborhoods. In addition, there is a positive relationship between water consumption and lot size and a reduction in water consumption over the research period from 2004 to 2012. The policy response varied widely across neighborhoods, and there was relationship between policy and annual income per capita, and household size; households with more income per capita are less responsive to the policy while bigger household sizes showed more policy responsiveness. Key words: City of Saskatoon, water rationing, water policy, water mandate, outdoor water use.
266

Transboundary water resource management of the Pongolo River/Rio Maputo.

Tompkins, Robyn. January 2002 (has links)
In the Twenty-first Century, sustainable water management is likely to be humanity's greatest challenge in a world of ever-increasing demand. Legal instruments both international and national regulate and provide a general framework for the use and management of international waters. Future basin management agreements can be informed by examining the degree of success, in terms of sustainability and equity, achieved by such agreements. That success can be influenced by the degree to which such agreements support the human right to water implicitly stated in international customary law, through a collaborative management approach. Since 1988, attempts by communities on the Pongolo floodplain to be involved in Pongolopoort Dam releases, have met with little success. Recently, the Department of Water Affairs and Forestry has begun to support those efforts, but the approach remains a sectoral one, and is primarily concerned with water issues. The South African National Water Act 36 of 1998 provides for environmental management and public participation, as well as providing explicitly for the rights of individual water users, but its implementation is hampered by an overwhelming emphasis on technical considerations and a lack of political will to embrace collaborative management systems. Little effort is expended on collaborative management methods, though the level of transparency in water management is improving, despite remaining highly centralised. The level and extent of incentives for local community participation is low, and systematic monitoring is in its early development. International river basin agreements generally take a top-down or state-driven approach, though there are some examples where local cross-border communities have participated successfully in the implementation of international agreements and management of transboundary basins. South Africa, Swaziland and M09ambique signed the Interim Incomaputo Agreement, which includes the Maputo basin, in August 2002. Once again, the approach to this agreement has been highly sectoral in that negotiations were handled entirely by water officials in the relevant countries. A lack of transparency has prevailed in the negotiation stages, though through the basin studies, which will inform implementation plans, the level of participation should improve. There is overwhelming consensus that integrated management is the key to sustainable international river basin management. Formal and systematic methods for inter-departmental communication, both nationally and internationally are currently not being implemented, which has significant negative impacts on integrated management. Research in this area represents an opportunity to explore collaborative management of an international river basin in an area that is, as yet, unstressed in terms of population and water supply. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2002.
267

An estimation of the value of water in the commercial forestry : two case studies from KwaZulu-Natal, South Africa.

Xaba, Thokozile P. January 2002 (has links)
The aim of this dissertation is to estimate the value of water in the commercial forestry in selected areas of Kwazulu-Natal. Furthermore, the essay focuses on two species:Eucalyptus grandis and Pinus patula. The estimation of the value of water is done using two types of water and they are evapo-transpiration (ET) and stream flow reduction (SFR). ET water is used because it has been discovered that there is a loss of water due to afforestation. On the other hand, SFR water is used because the existence of trees means that the water that is supposed to flow to the streams does not, as it is absorbed by the trees. Moreover, the essay develops two methods that can be used to estimate these two types of water in the commercial forestry. The methods are the residual method and the marginal value product (MVP) method. In the case of the residual method, the results are diverse. This means that the values of water for eucalyptus using the ET water, ranges from 05 cents to 23 cents. With the pinus patula, the values of water ranges from 01 cents to 03 cents. This is clear that the value of water for eucalyptus grandis using the ET water is higher than the pinus patula. The value of water using the MVP method using the ET water is decreasing. This means that the values of water starts from higher values to the lowest. This is due to the fact that we are estimating the marginal product. The values start from 72 cents and go down to 28 cents in the case of eucalyptus grandis. The values for the pinus patula start from 26 cents and go down to 12 cents. When estimating the value of water using SFR water, we do not use the residual method. We use the MVP method instead. The values obtained show that eucalyptus grandis values are higher than those of the pinus patula. They start from R5.1 0 cents and go down to R2.77 cents for eucalyptus grandis and from R2.39 to R1.03 for pinus patula. The methods used show that the economies of scale are present, because when we add more water, the value falls. Furthermore, The law of diminishing marginal retums is present because when we add more water; the values reach a maximum point and then start to fall. These two factors comply with the economic theory. / Thesis (M.Com.)-University of Natal, Durban, 2002.
268

Best management practices to attain zero effluent discharge in South African industries / C.G.F. Wilson

Wilson, Christiaan Georg Frederick January 2008 (has links)
Wastewater treatment is traditionally considered a separate part of an industrial activity, hardly connected to the production units themselves. It is nowadays essential to ensure that the quality of water is not degraded and that water that has been polluted is purified to acceptable levels, especially in a country with scarce water resources such as South Africa. Where water quality is concerned, Zero Effluent Discharge (ZED) is the ultimate goal, in order to avoid any releases of contaminants to the water environment. The push towards ZED in South Africa is also promoted further by the South African Government’s plan to reduce freshwater usage and the pollution of water sources due to the water scarcity in a semi-arid South Africa. Future legislation will see a marked increase in the cost of freshwater usage and/or a possible limitation of the quantity of freshwater available. There is a need in the South African Industry for a framework of Best Management Practices (BMPs) in order to provide interested stakeholders, which include not only industry, but also academia, environmental interest groups and members of the public, with a procedure to meet the ZED statutory requirements. This dissertation explores the regulatory requirements and current environmental management practices implemented. A framework of BMPs to successfully attain ZED status in South African industries is developed from the literature study and the researcher’s own experience. The BMP framework embodies practices for one integrated strategy within three dimensions. The three dimensions of the BMP framework were selected to differentiate between BMPs for management (Governance BMPs), the project management team responsible for ZED projects (Project Management BMPs) and the implementation of preventative and operational measures to obtain and sustain ZED compliance for South African industries. The BMP framework was validated against the practices applied by Mittal Steel. The Mittal Steel plant in Vanderbijlpark implemented various projects, reduced the intake of water and eliminated the discharge of effluent and by doing this successfully realised their ZED status. The BMP framework will enable South African industries to develop their own BMPs Manual which should be specific to their operational and environmental requirements. The implementation of these BMPs should be tailored and used accordingly to demonstrate compliance to ZED requirements in South African industries. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2009.
269

Best management practices to attain zero effluent discharge in South African industries / C.G.F. Wilson

Wilson, Christiaan Georg Frederick January 2008 (has links)
Wastewater treatment is traditionally considered a separate part of an industrial activity, hardly connected to the production units themselves. It is nowadays essential to ensure that the quality of water is not degraded and that water that has been polluted is purified to acceptable levels, especially in a country with scarce water resources such as South Africa. Where water quality is concerned, Zero Effluent Discharge (ZED) is the ultimate goal, in order to avoid any releases of contaminants to the water environment. The push towards ZED in South Africa is also promoted further by the South African Government’s plan to reduce freshwater usage and the pollution of water sources due to the water scarcity in a semi-arid South Africa. Future legislation will see a marked increase in the cost of freshwater usage and/or a possible limitation of the quantity of freshwater available. There is a need in the South African Industry for a framework of Best Management Practices (BMPs) in order to provide interested stakeholders, which include not only industry, but also academia, environmental interest groups and members of the public, with a procedure to meet the ZED statutory requirements. This dissertation explores the regulatory requirements and current environmental management practices implemented. A framework of BMPs to successfully attain ZED status in South African industries is developed from the literature study and the researcher’s own experience. The BMP framework embodies practices for one integrated strategy within three dimensions. The three dimensions of the BMP framework were selected to differentiate between BMPs for management (Governance BMPs), the project management team responsible for ZED projects (Project Management BMPs) and the implementation of preventative and operational measures to obtain and sustain ZED compliance for South African industries. The BMP framework was validated against the practices applied by Mittal Steel. The Mittal Steel plant in Vanderbijlpark implemented various projects, reduced the intake of water and eliminated the discharge of effluent and by doing this successfully realised their ZED status. The BMP framework will enable South African industries to develop their own BMPs Manual which should be specific to their operational and environmental requirements. The implementation of these BMPs should be tailored and used accordingly to demonstrate compliance to ZED requirements in South African industries. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2009.
270

Changes in the Freshwater System : Distinguishing Climate and Landscape Drivers

Jaramillo, Fernando January 2015 (has links)
Freshwater is a vital resource that circulates between the atmosphere, the land and the sea. Understanding and quantifying changes to the partitioning of precipitation into evapotranspiration, runoff and water storage change in the landscape are required for assessing changes to freshwater availability. However, the partitioning processes and their changes are complex due to multiple change drivers and effects. This thesis investigates and aims to identify and separate the effects of atmospheric climate change and various landscape drivers on long-term freshwater change. This is done based on hydroclimatic, land-use and water-use data from the beginning of the twentieth century up to present times and across different regions and scales, from catchment to global. The analyzed landscape drivers include historic developments of irrigated and non-irrigated agriculture and flow regulation. The thesis uses and develops further a data-motivated approach to interpret available hydroclimatic and landscape data for identification of water change drivers and effects, expanding the approach application from local to continental and global scales. Based on this approach development, the thesis identifies hydroclimatic change signals of landscape drivers against the background of multiple coexisting drivers influencing worldwide freshwater change, within and among hydrological basins. Globally, landscape drivers are needed to explain more than 70% of the historic hydroclimatic changes, of which a considerable proportion may be directly human-driven. These landscape- and human-driven water changes need to be considered and accounted for also in modeling and projection of changes to the freshwater system on land. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.</p> / VR, project 2009-3221

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