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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.
1

Methods for Characterizing Groundwater Resources with Sparse In-Situ Data

Nishimura, Ren 14 June 2022 (has links)
Groundwater water resources must be accurately characterized in order to be managed sustainably. Due to the cost to install monitoring wells and challenges in collecting and managing in-situ data, groundwater data is sparse in space and time especially in developing countries. In this study we analyzed long-term groundwater storage changes with limited times-series data where each well had only one groundwater measurement in time. We developed methods to synthetically create times-series groundwater table elevation (WTE) by clustering wells with uniform grid and k-means-constrained clustering and creating pseudo wells. Pseudo wells with the WTE values from the cluster-member wells were temporally and spatially interpolated to analyze groundwater changes. We used the methods for the Beryl-Enterprise aquifer in Utah where other researchers quantified the groundwater storage depletion rate in the past, and the methods yielded a similar storage depletion rate. The method was then applied to the southern region in Niger and the result showed a ground water storage change that partially matched with the trend calculated by the GRACE data. With a limited data set that regressions or machine learning did not work, our method captured the groundwater storage trend correctly and can be used for the area where in-situ data is highly limited in time and space.
2

Management of small towns water supply, Ghana

Braimah, Clifford Abdallah January 2010 (has links)
Delivering improved water services in small towns in low-income countries encompasses particular challenges. Often considered too large to be effectively community managed , small towns may also be too small, with too limited economies, to benefit from utility style professionalism and economies of scale. The most recent paradigm, that financially sustainable water services will be best achieved through the Demand Responsive Approach , has been complemented in Ghana, the focus of this study, through the development of a variety of management models, community, local government, national utility and private providers, to deliver DRA. Taking advantage of this unusual situation, in having a wide range of different functioning models in one country at the same time, this research has sought to investigate these management models with respect to effectiveness, equity, financial sustainability and efficiency of services delivery. However, the context in which all of these models operate relates to consumers effective demand, key to delivering a demand responsive approach. A second objective, necessary to validate any results relating to management models, has therefore been to investigate households actual demand for improved and alternative sources of water. Data for the research was gathered from examples of the four management models in use in Ghana, from eight small towns spread across the length and breadth of the country. The methodology incorporated key-informant interviews, user observations, household surveys and an analysis of relevant documents of operators and policy makers. The fieldwork was undertaken in two separate periods, designed to ensure that any effects of dry and wet season variations, which influence water supply delivery as well as demand, were adequately captured. The research found that none of the management models in use in small towns in Ghana could be considered to be significantly more effective than any other; overall, households demonstrated a limited demand for water supply with even this demand distributed among a number of sources, both formal, improved and alternative, traditional sources; this demand was not so much a function of affordability, rather a clear choice as to where to use limited resources mobile phone access absorbing three times the amount spent on water. Whilst certain management characteristics were found to make a difference, leadership in particular, no one model was able to influence the overarching water source effect, that is the cost of formal supply (surface water costing approximately three times more than ground water), relative to access to alternative, free supplies in the context of limited overall demand for water.
3

An assessment of the influence of water allocation on sustainable water resources management: A case study of the Nyando river basin, Kenya

Sungu, Ronald O. January 2018 (has links)
Philosophiae Doctor - PhD / Water problems prevalent in the Nyando River Basin are due to an ineffective water allocation system and lack of adequate conditions for implementation of sustainable integrated water resources management (IWRM) strategies. The basin is bedevilled by poor water resources management, inequitable allocation of water among consumers, physical infrastructural deficiencies, inefficient water utilisation, illegal water abstractions, natural resource mismanagement, conflicting and weak institutional roles and lack of stakeholder involvement in water resource management. The results of the study reveal sufficient per capita annual water availability with the potential to realise both Sustainable Development Goals (SDGs) and the Kenyan Vision 2030. However, analyses from flow duration curves (FDCs) and the water evaluation and planning (WEAP) model show that monthly water demands including environmental flow requirements (EFRs) are met only between 43% and 94% of the time. While the Water Act (2002) upholds the principles of IWRM on equitable and sustainable water resources allocation, in practice the current water allocation system falls short of implementing these strategies due to lack of a water allocation plan (WAP), inadequate water demand management (WDM), low infrastructural development and lack of community participation in WRM. For example, the total revenue generated in water supply schemes is only about 25 to 30% of their operational costs, which means that in the absence of subsidies the schemes cannot operate. The goal of this study was to examine the influence of the current water allocation system on water resources management in the Nyando River Basin by comparing the various sectoral water demands in the basin with the available water resources in order to improve understanding of how water allocation systems work in practice. The analyses further revealed that irrigation uses up to 72% of the available water, which is mainly drawn from the regular low flow contrary to the permit order. For example, the Ahero National Irrigation Scheme is permitted to draw 47 m3/day of water from regular flow and 13,500 m3/day from flood flow, but draws the whole amount from the regular flow; hence irrigation is the main cause of water deficits in the basin. Projections show that the irrigation sector will experience 300% increase in an unmet demand of 92.4 Mm3 by 2030 up from the current annual deficit of 2.9 Mm3. In light of the above challenges, both improvement of WDM and infrastructural provision have complementary roles in contributing to sustainable water availability, socioeconomic growth and poverty eradication in the basin and help achieve SDGs at the local scale. The results of the study will facilitate an understanding of the influence of water allocation systems on regional hydrology and form the basis of improving water allocation systems, and inform policy formulations to ensure sustained water availability and environmental sustainability in river basins. In that regard, this study contributes to the on-going global debate on Sustainable Development Goals by exploring ways of realising and improving IWRM strategies and the National targets.
4

ADAPTATION STRATEGIES TO IMPACTS OF CLIMATE CHANGE AND VARIABILITY ON TEHRAN WATER SUPPLY IN 2021 : AN APPLICATION OF A DECISION SUPPORT SYSTEM (DSS) TO COMPARE ADAPTATION STRATEGIES

Saemian, Sina January 2013 (has links)
In this thesis, the decision analysis process of investigating the best optimal strategy for Tehran water management in 2021 is described. Such process is normally divided into four steps including: structuring the problem; identifying feasible strategies, their impact and uncertainty; quantifying preferences; and evaluation of countermeasures and sensitivity analysis. Here, in order to structure the problem, the characteristics of Tehran with respect to water issues and its history of water management are reviewed. The state of surface waters and ground waters and a description of Tehran plan for waste water treatment are given, the most significant constraints of Tehran water sector are classified and the challenges of climate change and variability are explained. The feasible adaptation strategies are designed subsequently based on that classification, data extracted from a survey and a number of interviews with water officials and managers and ordinary citizens in Tehran. Each strategy contains a series of separate measures with different weights. The phase of quantifying preferences and elucidating utility functions is conducted based on the data available from previous studies and also the current survey. The measures include: installing water saving devices, awareness raising to change citizens’ water consumption pattern, adding new sources of surface water, investing on waste water utilization, migration control and repairing water distribution network.Different combinations of these measures provide different possibilities for formulating adaptation strategies. We compare two more discussed adaptation strategies of the spectrum of strategies; one is inclined toward exploiting more water resources while the other one is more focused on demand management. The former is mainly supported by water officials and the latter advocated by water experts we interviewed. The criteria of comparison are social acceptability, economic feasibility, time-efficiency and environmental tenability. By considering the uncertainty attributed to the criteria weights, the WEB-HIPRE DSS analysis shows that the demand-oriented strategy is the optimal one in most cases, however, if time-efficiency and/or economic feasibility gain very high significance, the strategy of water officials wins over that of experts.
5

The development of an in house greywater and roof water reclamation system for large institutions during 1994 to 1998

Surendran, Sundaralingam S. January 2001 (has links)
For sustainable water management, here is a necessity to consider alternatives, in addition to conventional systems. The aim of this research is to develop and demonstrate a sustainables, from and greywater reclamation system for WC flushing and it was started in 1994. In the UK there are no water quality standards for WC flushing water use. There were no design guidelines for greywater water reclamation and no published study on the supply-dernandb alance, in detail, for water recycling in institutions such as universities. The research has shown the feasibility of planned direct grey and storm water reclamation and recycling system to manage growing water and wastewater problems. This thesis is based on the information gathered from 4 universities, 3 hotels and 3 recreational centres, and experiences gained at Loughborough University during the development and demonstration of the full scale "in-house grey and roof water" reclamation and recycling systems. The water use, greywater quality and roof water characteristics were studied in detail and this information was used for the development of the reclamation and recycling system. The studies showed that the water usage at the university halls were not similar to usage in households. Unlike large water supply schemes, small in-house systems generate a large peak factor for water use. To avoid deficit, in addition to personal washing waters, a top-up of laundry wastewater or roof water, and a well-designed balancing tank is necessary. The demonstration study shows that there was no standby mains' water used, which means that the water reclaimed was sufficient for reuse. The quality characterisation study shows that the greywater and first flush storm water roof runoff were polluted. The characteristics of combined grey and roof water are suitable for biological treatment. Based on the infomation, a lab-scale unit was developed; the reactor characteristics and performance such as head losses and removal efficiency were monitored; and the unit was refined. Two novel multi-barrier reclamation systems were developed to achieve sufficient quantity and near potable quality of water with minimum maintenance and cost. During 1997 the grey and roof water recycling system with laboratory tested physical and biological reclamation processes without the use of coagulants and disinfection were installed. The performance of the treatment system was closely monitored until 1998. This provided benefits in near potable quality of reclaimed water, low head loss, reliability, failure free operation and simple maintenance. The reclaimed effluent from Project I and 2 met the UK/EU bathing water standards and was also able to meet the US EPA standards for WC flushing. The microbial (using coliform as an indicators) quality of reclaimed water without disinfection is acceptable for controlled recycling systems (carefully monitored and fully informed). There were no odour problems in the treated water or sludge blockages. Comparatively, Project I was more efficient at removing coliform, turbidity, solids (suspended, dissolved, volatile), and Project 2 better at removing carbon (organic and inorganic). A simple cost benefit analysis done for the recycling system at Royce Hall of Residence showed 10 years pay back. More detailed cost-benefit analysis including comparisons of new built and retrofit recycling system and fife cycle analysis are recommended. This study shows that most of the people questioned were accepted and were willing to consider using the recycling system for toilet flushing, if the water was clear, colourless, odour free, carried no risk and gave cost-benefits. During the demonstration stage the users willingly accepted non-potable grey water reuse.
6

Jämförelse av strategier och lösningar för hållbar utveckling av VA-verksamheten i Jönköping och Borås kommun / A comparison of strategies and solutions towards sustainable development of water infrastructure in the municipalities of Jönköping and Borås

Ranerfors, Martin, Nilsson, Martin January 2018 (has links)
Abstract Purpose: The purpose with this thesis is to identify the problems that these two municipalities, Jönköping and Borås, are facing in regard to sustainable development in the water infrastructure area and highlight the different strategies that the municipalities has developed to find solutions to these problems. Two municipalities have been chosen for this analyse, the municipalities of Borås and Jönköping, for the reason that they both have similar population but two different solutions in how the municipality water management is run. The questions that the thesis are built on is: 1)    How do these two municipality work towards a sustainable development in water management? 2)    What are these strategies based on? 3)    How does the checklist for sustainable development been developed and how does it differ between the two municipalities? Method: The method of finding the answers to these questions is six qualitative interviews with people from both organizations with knowledge of the subject. Literature studies of the theories behind sustainable development in water infrastructure and analysing documents provided by the municipalities in order to scientifically back up the findings from the interviews. Findings: After analysing the collected data one can see that sustainability is already a part of water management in general but there is some focus areas that the organizations are working on with different tools which is presented in a checklist. Implications: There are three conclusions that could be made from this thesis, they are about legal requirements, technical development and sustainability index.    Limitations: This thesis is of limited size and is therefore an overview of these organizations work towards sustainable development. The thesis does not bring up the political aspect and does not do a deeper analysis of the different aspects of water management.  Keywords: sustainable development, sustainable water management, water management
7

Making power explicit in sustainable water innovation: Re-linking subjectivity, institution and structure through environmental citizenship.

Wong, S., Sharp, Liz January 2009 (has links)
no / This article offers a new perspective on environmental citizenship by proposing the 'subjectivity-institution-structure' framework. Applying the framework to a sustainable water innovation project in north-west England, it argues that the meaning of environmental rights, the understanding of required environmental responsibilities, and the degree of public participation in decision-making, are shaped by individuals' subjective values, institutional arrangements and structural conditions. Our framework makes power explicit in the practice of environmental citizenship. It is intended to help set reasonable targets for sustainable development actions, which is particularly important when working with individuals with limited power.
8

A multi-criteria decision analysis framework for sustainable rainwater harvesting in Ibadan, Nigeria

Lade, Omolara January 2014 (has links)
The approach to water management worldwide is currently in transition, with a shift from centralised infrastructures to greater consideration of decentralised technologies, such as rainwater harvesting (RWH). Initiated by recognition of drivers, including water demand, increasing risk of ground-water pollution and flooding, the value of RWH is filtering across the academic-policy boundary. However, in Nigeria, implementation of sustainable water management (SWM), such as RWH systems, is inefficient social, environmental and technical barriers, concerns and knowledge gaps exist, which currently restrict its widespread utilisation. This inefficiency contributes to water scarcity, water-borne diseases, and loss of lives and property due to flooding. Meanwhile, several RWH technologies have been developed to improve SWM through both demand and storm-water management. Such technologies involve the use of storage tanks, surface water reservoirs and ground-water recharge pits as storage systems. A framework was developed to assess the significance and extent of water management problems, match the problems with existing RWH-based solutions and develop a robust ready-to-use multi-criteria analysis tool that can quantify the costs and benefits of implementing several RWH-based storage systems. The methodology adopted was the mixed method approach, involving a detailed literature review, followed by a questionnaire survey of 1067 household respondents, 135 Nigerian Architects and Civil Engineers and focus group discussion with Stakeholders. A total of 1042 sets of data were collected through a questionnaire survey and analysed using SPSS, Excel and selected statistical methods to derive weightings of the attributes for the tool. Following this, three case studies were selected to collect data for hydrological modelling using the RainCycle model. From the results it is found that the most important barrier constraining sustainable RWH regime in Ibadan was obsolete and insufficient operational equipment, followed by poor renumeration of water corporation staff and misuse of available funds. In addition, the measure of importance of storage capacity was established, with the highest score of 4.5 which reflects the general inadequacy of storage as a major barrier to the adoption of RWH as a sustainable water management method. Further, respondents’ major health hazards associated with drinking contaminated water was established. A larger proportion (61.2%) of respondents chose prevalence of typhoid fever; some have a prevalence of diarrhea (19.4%), while few of respondents’ water sources is free from water-borne diseases (2.3%). The tool developed is an integrated platform of related evaluation techniques, including Whole Life Cycle Cost Analysis and Multi-Attribute Utility Theory. The tool uses data including cost and quantities of materials for building a RWH storage system and quantifies the cost and benefits of alternative RWH-based systems that can improve project management. This tool is novel, given its integration of the analytical techniques mentioned above and application for selecting the most appropriate RWH-based SWM systems. The implementation of the tool is envisaged to provide an objective platform for the quantification of the costs and benefits of RWH-based systems prior to implementation.
9

Clean water from clean energy : removal of dissolved contaminants from brackish groundwater using wind energy powered electrodialysis

Malek, Payam January 2015 (has links)
Around 770 million people lack access to improved drinking water sources (WHO 2013), urgently necessitating implementation of contaminant removal by e.g. desalination systems on a large scale. To improve water quality and enable use of brackish water sources for human consumption in remote arid areas, a directly coupled wind – electrodialysis system (Wind-ED) was developed. Modularity, sustainability and above all suitability for the practical use in off-grid locations were the main motivations and design objectives. The direct coupling of wind energy with membranes reduces the system costs as well as technical drawbacks associated with using intermediate energy storage systems. During this research, systematic experiments were performed using the Wind-ED system in order to determine desalination performance and clean water production, specific energy consumption (SEC) and current efficiency (ηc) under relevant conditions, such as varying: i) wind speed, ii) wind turbulence intensity, iii) oscillation periods, iv) varying NaCl concentrations and v) flow rates. Moreover, the competitive removal of four commonly available inorganic contaminants in brackish groundwater sources, nitrate (NO3-), fluoride (F-), sulphate (SO42-) and chloride (Cl-), were investigated. Firstly, to establish a systematic understanding of how and to what extent energy fluctuations influence the transport of the salt (i.e. NaCl) ions across the membranes, experiments were conducted using pulsed electric field assisted electrodialysis (pulsed-ED) over a wide range of frequencies (0.001 – 10 Hz) and duty cycles (20 – 80). The results showed that pulsation applied in the sub-limiting regime resulted in reduced water production, explained by the delays caused by the off-periods during the pulsed desalination process. At higher current densities, pulsation led to considerable improvements in current (e.g. up to 95%, for a feed solution of 500 mg/L and a pulse regime of 1 Hz at 50 V peak voltage) and significant reduction in water dissociation, explained by a reduction of concentration polarisation. Importantly, the pulsation had no significant effect on energy consumption or current efficiency suggesting that ED could be suitable for direct coupling to fluctuating energy sources such as wind energy. ED was consequently coupled to a wind turbine system and a series of desalination tests were performed over a wide range of wind speeds (2-10 m/s), turbulence intensities (TI of 0-0.6) and oscillation periods (0-180 s). Results showed that water production and SEC increased with wind speed. However, both the water production and SEC stopped increasing as the power output from the turbine levelled off at wind speeds above the rated value (vrated: 7.9 – 8.4 m/s). The impact of wind speed fluctuations on the system performance were insignificant up to a TI of 0.4. The desalination performance declined under high turbulence intensity fluctuations (TIs ≥ 0.5) and long periods of oscillation (> 40 s), as the wind-ED system periodically cycled off in response to operation below the cut-in wind speed of the wind turbine (vcut-in: ~ 2 m/s). The off-cycling of the system caused significant delays in the desalination process, and thus resulted in reduced water production. Further reduction in the water production resulted as the wind-ED system operated under intermittent wind speed conditions with off-wind periods longer than 10 s. It was concluded that the main challenge in direct coupling of ED to a wind resource was not the magnitude of the fluctuations but the impact of the power cycling off during long periods of oscillation and lengthy periods of no wind. Interestingly, the SEC of the process remained relatively unaffected by the fluctuations and intermittencies in the wind resource. The effect of energy fluctuations on the competitive transport of F-, Cl-, NO3- and SO42- from artificial brackish water (TDS ~4350 mg/L) was investigated using different sets of real wind data. The ion removal, independent of the wind regime tested, followed the order: NO3- ≥ Cl- > F- > SO42-. The competitive removal of the ions was linked to differences in physicochemical properties (i.e. hydration energy, ionic mobility and valence). The specific selectivity (e.g. preferential transport of NO3- over SO42- ions) was found to increase with concentration polarisation being either minimised (by lowering the mean wind speed) or disrupted (by fluctuations in the wind resource). The results from flow rate and feed concentration experiments, showed that power production of the wind turbine depended on not only the available wind energy but also the resistance of the load (i.e. the ED stack). Thus, increasing the feed concentration and the flow rate resulted in reduced resistance in the ED stack (Rstack), which inversely influenced the current induction counter torque force applied on the shaft of the wind turbine and caused the rotor to spin at a lower angular velocity. This led to increased sensitivity of the wind-ED system to wind speed fluctuations (e.g. system cycled off due to extreme fluctuations and intermittencies with low TDS feed concentration of 2400 mg/L) and hence a reduction of desalination performance. Impact of flow rate on the SEC was found to be negligible; this was attributed to the automatic voltage to current adjustments done by the wind turbine, in order to minimise the impacts of Rstack on the power production by the turbine at a given wind speed. Increased flow rate and resulting shrinkage of the boundary layer’s thickness, caused the concentration profiles at the solution-membrane interface to become steeper. This favoured the transport of ions with the highest diffusion coefficients in the mixture (i.e. Cl- and NO3-). Decreased flow rate favoured the transport of ions with larger valence numbers and higher electric mobility inside the electrolyte (i.e. SO42-); as the former property governed the faster migration of SO42- ions through the thick boundary layer and the latter property assisted with the improved affinity of the ion-exchange membrane to SO42- ions compared to the monovalent anions in the mixture. Increasing the feed concentration of Cl- from 500 to 2,550 mg/L led to reduced transport numbers for the other anions in the mixture and significantly reducing their removal rate. The results obtained from both the pulsed-ED and wind-ED experiments showed that, despite direct coupling to the fluctuating energy source the SEC of the process remained relatively unaffected by the energy fluctuations. Although the desalination process might require more time to be completed when operating under extreme wind speed fluctuations and intermittencies, the quality of the drinking water produced was always within the WHO standards. In conclusion, the findings from this research prove the wind-ED system to be an energetically robust and a reliable off-grid desalination technique suitable for the treatment of brackish groundwater in water stressed remote regions.
10

The potential for water freight in the South West UK

Chacko, Sapna January 2018 (has links)
The role of water freight as a sustainable mode of transportation often receives special attention in logistics and transportation. Due to rising environmental concerns UK national policy supports an increase in the amount of freight movements on commercial waterways. Within this context this research investigates the potential for water freight in the South West (SW) UK especially in Cornwall and Devon (CAD). This study is exploratory and following literature searches Delphi methods were selected with which to gather primary data. The research required three rounds of Delphi surveys. Following this, a focus group with the members of the 'Maritime and Waterborne Innovation Group' in the SW UK was conducted to measure the trustworthiness of the Delphi findings. The Delphi study achieved consensus on eight statements. Results indicated that the presence of an extensive coast line with accessibility to several coastal ports is conducive to the effective management of water freight movements in the region. The focus group discussion provided fuller explanations, suggestions and statements of issues which require further exploration for the development of water freight. This study reveals the latest information and possibilities and helped to articulate the importance of using water freight in SW UK. The results of this research also have many implications for the rest of the world where water freight is either in its infancy or aiming to increase its usage. The suggestions, observations and information collected during the Delphi study and from the focus group participants will assist in formulating strategies to improve the efficiency and effectiveness of water transportation within a region or a country.

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