No description available.

With the prediction that South Africa will be water-stressed by the year 2025, it becomes necessary for all the cities in the country, including Johannesburg to take the necessary measures to ensure that they manage their water resources effectively in order to ensure the water security of their cities. This research report is a secondary case study of the groundwater situation in Johannesburg, which delves into the literature on groundwater and presents a review of the groundwater problems in Johannesburg and the management strategies used in managing the problems. Some of the groundwater issues identified in Johannesburg include recharge problems due to the geological formation and nature of aquifers in Johannesburg, and the growth and urbanization of Johannesburg, which places increasing demands on water. There is also the problem of pollution, the sources of which in Johannesburg are mainly municipal waste, industrial processes and mining activities. There are also institutional capacity problems regarding the management of groundwater in Johannesburg. The second aspect of the research report delves into the management strategies employed in the city of Johannesburg for the management of groundwater resources. Some of the management strategies or tools discussed include the National Water Resource Strategy 2 (NWRS), the Groundwater Strategy 2010, the guideline for the assessment, planning and management of groundwater resources in South Africa and the NORAD toolkit. Although these tools are well developed for the management of groundwater, there are deficiencies in implementation, which are mainly due to the undervaluation of the importance and significance of groundwater resources, shortage of expertise and adequate data, centralization of power, disregard of groundwater ecosystems and associated goods and services, and the lack of adaptive management. In order to deal with the issues and problems surrounding groundwater in Johannesburg, some of the solutions recommended include effective administration, capacity building and cooperative governance, acknowledging the importance of groundwater-dependent ecosystems, the need for adaptive management, and integrating supply side and demand side measures in the management of groundwater, and the development of a groundwater management framework (GWMF) for the city of Johannesburg. Key Words: Groundwater, sustainable development, management strategies, Johannesburg

Not available / text

Anomalous concentrations of silica in ground water of the eastern San Joaquin Valley originate from several diverse sources and are subsequently modified by recharge or diagenesis. Statistics, geochemical models, and column studies identified potential sources of silica in ground water and those parameters most important in influencing its distribution. Principal components analysis indicated inverse time and potassium as the parameters which best relate to silica. Inverse time relates to ground-water recharge while potassium relates to either the rhyolitic Friant Pumice, the hardpans of the eastern San Joaquin Valley, or diagenetic losses. A lumped parameter model suggests that recharge is responsible for the drop in silica concentrations beneath Fresno since 1971. The Madera County model indicates higher silica concentrations associated with the Friant Pumice, older geologic units with hardpans, finer grained sediments, and areas of ground-water discharge. Lower silica concentrations are associated with unweathered sediments, areas receiving recharge, and areas underlain by the Corcoran Clay. Column leaching studies produced silica concentrations from the Friant Pumice of up to 90 mg/1, Turlock Lake and Riverbank Formation hardpans from 40-50 mg/1, and younger Modesto Formation sediments from 10-40 mg/l. Spatially, volcanogenic sediments impart the highest silica concentrations to the ground water, 70-95 mg/1, and occur along the eastern margin of the valley, north of the San Joaquin River, or in San Joaquin River fluvial deposits. Iron-silica hardpans, found at various depths along the east side of the valley, are associated with silica concentrations of 40-70 mg/l. The typical arkosic sediments of the eastern valley have silica concentrations of 20-40 mg/l. Silica concentrations in ground water are modified by recharge and diagenetic processes. Either natural or artificial recharge having 4-16 mg/1 silica may lower ambient silica concentrations in ground water. Recharge occurs beneath some rivers and in transmissive paleochannel deposits; artificial sources include agricultural overirrigation and basin recharge. The down-gradient loss of silica to the sedimentary column, more prevalent at depth, apparently is by the sorption of silica on clays, the formation of clays, or deposition of amorphous silica.

With increasing demand and pressures on groundwater resources, accurate and reliable groundwater prediction models are essential for sustainable groundwater management. Groundwater models are merely approximations of reality, and we are unable to either fully characterize or mathematically describe the true complexity of the hydrologic system; therefore, inherent in all models are varying degree of uncertainty. A robust management policy should consider uncertainties in both the imprecise nature of conceptual/numerical models and their parameters. This study addresses the critical question of whether the use of multiple conceptual models to explicitly account for conceptual model uncertainty improves the ability of the models to assist in management decisions. Twelve unique conceptual models, characterized by three alternative geological interpretations, two recharge estimations, and two boundary condition implementations, were formulated to estimate sustainable extraction rates from Thailand’s Thaphra Area, where increasing groundwater withdrawals may result in water level declination and saline water upconing. The models were developed with MODFLOW and calibrated using PEST with the same set of observed hydraulic head data. All of the models were found to reasonably produce predictions of the available heads data. To select the best among the alternative models, multiple criteria have been defined and applied to evaluate the quality of individual models. It was found that models perform differently with respect to different evaluation criteria, and that it is unlikely that a single inter-model comparison criterion will ever be sufficient for general use. The chosen alternative models were applied both individually and jointly to quantify uncertainty in the groundwater management context. Different model-averaging methods were assessed in terms of their ability to assist in quantifying uncertainty in sustainable yield estimation. The twelve groundwater simulation models were additionally linked with optimization techniques to determine appropriate groundwater abstraction rates in the TPA Phu Thok aquifer. The management models aim to obtain maximal yields while protecting water level decline. Despite similar performances among the calibrated models, total sustainable yield estimates vary substantially depending on the conceptual model used and range widely, by a factor of 0.6 in total, and by as much as a factor of 4 in each management area. The comparison results demonstrate that simple averaging achieves a better performance than formal and sophisticated averaging methods such as Maximum Likelihood Bayesian Model Averaging, and produce a similar performance to GLUE and combined-multiple criteria averaging methods for both validation testing and management applications, but is much simpler to implement and use, and computationally much less demanding. The joint assessment of parameter and conceptual model uncertainty was performed by generating the multiple realizations of random parameters from the feasible space for each calibrated model using a simple Monte Carlo approach. The multi-model averaging methods produce a higher percentage of predictive coverage than do any individual models. Using model-averaging predictions, lower optimal rates were obtained to minimize head constraint violations, which do not ensue if a single best model is used with parameter uncertainty analysis. Although accounting for all sources of uncertainty is very important in predicting environmental and management problems, the available techniques used in the literature may be too computationally demanding and, in some cases, unnecessary complex, particularly in data-poor systems. The methods presented here to account for the main sources of uncertainty provide the required practical and comprehensive uncertainty analysis and can be applied to other case studies to provide reliable and accurate predictions for groundwater management applications.

Stochastic two-stage programming, a main branch of stochastic programming, offers models and methods to find the optimal objective function and decision variables under uncertainty. This dissertation is concerned with developing an approximate procedure to solve the stochastic two-stage programming problem and applying it in relative field. Five methods used in evaluating the expected value of function for distribution problem are discussed and their basic characteristics and performances are compared to choose the most effective approach for use in a two-stage program. Then the stochastic two-stage programming solving method has been established with the combination of a genetic algorithm (GA) and point estimation (PE) procedure. This approach avoids the inherent limitations of other methods by using PE to estimate the expected value of recourse function and the GA to search optimal solution of the problem. To extend the advantage of GA the modified genetic algorithm (MGA) is built to improve the performance of GA. Finally, the whole procedure is used in several examples with different kinds of variable and linear or nonlinear style objective functions. A stochastic two-stage programming model for an aquifer management problem is set up with considering conductivity and local random recharge as the source of uncertainty in the system. The designed procedure includes the response matrix process that replaces the partial differential flow equation, Girinski potential process and a pre-setup process that makes the response matrix process application in general aquifer random field possible. Other chosen problems are solved with designed approach to illustrate the effects of uncertainty source in the stochastic programming model and compared with results with ones given in literatures.

<p><font face="Times New Roman"><font face="Times New Roman"> <p align="left">The research problem for this study is the limited and unsuccessful implementation of the IWRM concept. This thesis has argued that comprehensive assessment of physical and socioeconomic conditions is essential to provide explanation on factors that limit the successful execution of the IWRM approach. It has further argued that the local IWRM works as proxy for full and successful implementation of the IWRM approach. To contextualise this thesis, the prevailing physical and socioeconomic factors in Malawi in relation to current management and usage of water resources were explained. With 1,321m per year, this study showed that Malawi is a physically water stressed country but not physically water scarce country although economically it is a water scarce country. This novelty is against some literature that present Malawi as a water abundant country. Again, this study showed that executing a full and successful IWRM in Malawi remains a challenge because of the prevailing socioeconomic situation in terms of water policies, water laws, institutions and management instruments. These aspects have not been reformed and harmonised to facilitate a successful operation of the IWRM approach. The main water-related problem in Malawi is the mismanagement of the available water resources. This is largely due to the lack of implementing management approaches which can generate systematic data for practical assessment of water resources to guide the coordinated procedure among water stakeholders working in catchments. This lack of implementing a coordinated management approach commonly known as integrated water resources management (IWRM) can be attributed to various reasons that include i) lack of comprehensive assessment of factors that can explain lack of successful IWRM implementation at catchment level and ii) lack of methods to demonstrate data generation and analysis on quantity, quality and governance of water that show practical operation of IWRM at community level using groundwater as a showcase among others. This study revealed that introducing local IWRM requires a prior knowledge of the evolution and role of the full IWRM concept in the international water policy which aimed at addressing broader developmental objectives. Globally, the current status of the IWRM concept has potential to address such broader developmental objectives, but sustaining IWRM projects where they have been piloted showed slow progress. Basing<font face="Times New Roman">&nbsp / on the factors that slow such a progress, local IWRM approach has emerged as a proxy to execute the full IWRM as demonstrated in chapter 8 in this thesis. However, the observed lack of sustainable resources to fund continual functioning of local IWRM activities will defeat its potential solution to water management challenges. The main threat for sustainable local IWRM activities is the tendency of national governments to decentralise roles and responsibilities to local governments and communities without the accompanying financial resources to enable the implementation of the local participation, investments and initiatives at local level. If this tendency could be reversed, the contribution by local IWRM towards solving management problems in the water sector will be enormous. Chapter four has provided the general case-study approach used in this study in terms of research design, data collection methods, data analysis methods, ethical consideration and limitation of the current study within the context of water resource management with a focus on groundwater management. Using geologic map, satellite images, photographs and hydrogeologic conceptual model, the following results emerged: 1) that the Upper Limphasa River catchment has fractured rock aquifer with limited permeability and storage capacity / 2) The topographic nature and north-south strikes of the lineaments explained the north-south flow direction of groundwater in the catchment / 3) The drainage system observed in the Kandoli and Kaning&rsquo / ina Mountains to the east and west of the Upper Limphasa River catchment respectively (Fig. 5.1 / Fig.5.2) formed a groundwater recharge boundary / 4) The regional faults in the same mountains (Fig. 5.1 / Fig.5.2) formed structural boundary as well as hydrogeologic boundary which controlled flow direction of the groundwater / 5) the hydrogeologic conceptual model showed the existence of the forested weathered bedrock in the upland areas of the entire catchment which formed no-flow boundary and groundwater divide thereby controlling the water flow direction downwards (Fig. 5.9) / 6) The major agricultural commercial activities existed in Lower Limphasa catchment while only subsistence farming existed in Upper Limphasa catchment. This knowledge and visualization from the map (Fig. 5.3) and conceptual model (Fig.5.9) showe interactions between upland and lowland areas and the role of physical factors in controlling groundwater flow direction in the catchment. It also provided the enlightenment on implications of socioeconomic farming activities on water management. These insights enabled this study to recommend the need for expedited implementation of holistic effective management for sustainable water utilization. <font face="Times New Roman">Using different physical factors, water scarcity indices and methodologies, this study showed that Malawi is a physically water stressed as well as an economic water scarce country. This novelty is against some literature that present Malawi as a water abundant country. Again, despite the high proportion (85%) of Malawians relying on groundwater resource, groundwater availability (storage in km 6.10) compared to other countries within SADC and Africa. Given the complexity of</font><font face="Times New Roman"> groundwater abstraction, the available groundwater for use is further reduced for Malawians who depend on such a resource for their domestic and productive livelihoods. Such insights provided the basis for discussing the need for IWRM. Although daily statistics on groundwater demand (i: 21.20 litres / 116.91 litres / 80,550.99 litres), use (ii: 16.8 litres / 92.55 litres / 63,766.95 litres) and abstracted but not used (iii: 4.4 / 24.36 / 16,784.04 litres) were relatively low per person, per household and per sub-catchment respectively, such statistics when calculated on monthly basis (i. Demand: 636 litres / 3,507.30 litres / 2,416,529.70 litres / ii.Use:504 litres / 2,776.5 litres / 1, 913, 008.5 litres iii. Abstracted but not used: 132 litres / 730 litres / 503, 521.2) / and on yearly basis (i. Demand: 7,632 litres / 42,087.6 litres / 28,998,356.4 litres / ii. Use: 6,048 litres / 33,318 litres / 22, 956, 102 litres / iii: Abstracted but not used: 1,584 litres / 8,769.6 litres / 6,042,254.4 litres) per person, per household and per sub-catchment provided huge amount of groundwater (Table 6.5). Given the limited storage capacity of fractured rock aquifer in the basement complex geology, the monthly and yearly groundwater demand and use on one hand and abstracted but not used on the other was considered enormous. With the population growth rate of 2.8 for Nkhata Bay (NSO, 2009) and the observed desire to intensify productive livelihoods activities coupled with expected negative effects of climate change, the need to implement IWRM approach for such groundwater resource in the study catchment remains imperative and is urgently needed. In addition to identifying and describing factors that explain the limited groundwater availability in the study catchment, the study developed a methodology for calculating groundwater demand, use and unused at both households and sub-catchment levels. This methodology provided step-by-step procedure for collecting data on groundwater demand and use as a tool that would improve availability of data on groundwater. Implications of such results for IWRM in similar environments were discussed. Despite<font face="Times New Roman">&nbsp / the time-consuming procedure involved in using the developed methodology, the calculations are simple and interpretation of results is easily understood among various stakeholders. Hence, such an approach is recommended for the IWRM approach which requires stakeholders from various disciplines to interact and collaborate. Nonetheless, this recommends the use of this method as its further refinement is being sought. The analysis on groundwater quality has shown that the dominant water type in the aquifers of Upper Limphasa catchment was Ca-HCO had shallow, fresh groundwater with recent recharged aquifer. Analyses on</font><font face="Times New Roman"> physicochemical parameters revealed that none of the sampled boreholes (BHs) and protected shallow dug wells (PSWs) had physical or chemical concentration levels of health concern when such levels were compared with 2008-World Health Organisation (WHO) guidelines and 2005-Malawi Bureau of Standards (MBS). Conversely, although the compliance with 2008-WHO and 2005-MBS of pathogenic bacteria (E.coli) in BHs water was 100% suggesting that water from BHs had low risk and free from bacteriological contamination, water from PSWs showed 0% compliance with 2008- WHO and 2005-MBS values implying high risk to human health. The overall assessment on risk to health classification showed that PSWs were risky sources to supply potable water, hence the need to implement strategies that protect groundwater. On the basis of such findings, the analysis in this study demonstrated the feasibility of using IWRM approach as a platform for implementing environmental and engineering interventions through education programmes to create and raise public awareness on groundwater protection and on the need for collaborative efforts to implement protective measures for their drinking water sources. The use of different analytical methods which were applied to identify the exact sources of the observed contaminants in the PSWs proved futile. Therefore, this study concluded that rolling-out PSWs either as improved or safe sources of drinking water requires further detailed investigations. However, this research recommended using rapid assessment of drinking water-quality (RADWQ) methods for assessing the quality of groundwater sources for drinking. Despite the study area being in the humid climatic region with annual rainfall above 1,000 mm, many of the physical factors were not favourable for availability of more groundwater in the aquifers. Such observation provided compelling evidence in this<font face="Times New Roman">&nbsp / study to commend the local IWRM as a proxy for the full IWRM implementation for sustainable utilization of such waters. Although institutional arrangements, water laws and water policy were found problematic to facilitate a successful implementation of full IWRM at national level in Malawi, this thesis demonstrated that local institutional arrangements, coordination among institutions, data collection efforts by local community members (active participation), self-regulation among local community committees were favourable conditions for a successful local IWRM in the Upper Limphasa River catchment. This research recommends continuation of such local participation, investment and initiatives as proxy for the full and successful IWRM beyond the study catchment. However, the observed lack of financial resource from central government to facilitates local IWRM activities were seen as counterproductive. In addition, this thesis recommended further studies which should aim at improving some observed negative implications of self-regulations on community members and the limited decentralisation elements from the Department of Water Development. Finally, one of the contributions from this study is the scientific value in using different methods to assess the quality of groundwater as presented in chapter 7. The second value is the demonstration of applying practical techniques to evaluate factors that explain the amount of groundwater storage in the aquifers that can be understood by water scientists, water users, water developers and water managers to implement IWRM collaboratively using groundwater as a showcase. The third contribution is the provision of the procedure to systematically generate data on demand (abstraction) and use of groundwater in unmetered rural areas which has the potential to guide water allocation process in the catchment. Fourthly, the thesis has provided a hydrogeologic conceptual model for the first time for Limphasa River catchment to be used as a visual tool for planning and developing management practices and addressing current water problems. Fifthly, the study has shown how local IWRM works at community level as a proxy for the full implementation of IWRM despite the absence of Catchment Management Agencies. The last contribution is the dissemination of results from this study made through publications and conference presentations as outlined in the appendix.</font></font></font></font></p> </font></font></p>

<p><font face="Times New Roman"><font face="Times New Roman"> <p align="left">The research problem for this study is the limited and unsuccessful implementation of the IWRM concept. This thesis has argued that comprehensive assessment of physical and socioeconomic conditions is essential to provide explanation on factors that limit the successful execution of the IWRM approach. It has further argued that the local IWRM works as proxy for full and successful implementation of the IWRM approach. To contextualise this thesis, the prevailing physical and socioeconomic factors in Malawi in relation to current management and usage of water resources were explained. With 1,321m per year, this study showed that Malawi is a physically water stressed country but not physically water scarce country although economically it is a water scarce country. This novelty is against some literature that present Malawi as a water abundant country. Again, this study showed that executing a full and successful IWRM in Malawi remains a challenge because of the prevailing socioeconomic situation in terms of water policies, water laws, institutions and management instruments. These aspects have not been reformed and harmonised to facilitate a successful operation of the IWRM approach. The main water-related problem in Malawi is the mismanagement of the available water resources. This is largely due to the lack of implementing management approaches which can generate systematic data for practical assessment of water resources to guide the coordinated procedure among water stakeholders working in catchments. This lack of implementing a coordinated management approach commonly known as integrated water resources management (IWRM) can be attributed to various reasons that include i) lack of comprehensive assessment of factors that can explain lack of successful IWRM implementation at catchment level and ii) lack of methods to demonstrate data generation and analysis on quantity, quality and governance of water that show practical operation of IWRM at community level using groundwater as a showcase among others. This study revealed that introducing local IWRM requires a prior knowledge of the evolution and role of the full IWRM concept in the international water policy which aimed at addressing broader developmental objectives. Globally, the current status of the IWRM concept has potential to address such broader developmental objectives, but sustaining IWRM projects where they have been piloted showed slow progress. Basing<font face="Times New Roman">&nbsp / on the factors that slow such a progress, local IWRM approach has emerged as a proxy to execute the full IWRM as demonstrated in chapter 8 in this thesis. However, the observed lack of sustainable resources to fund continual functioning of local IWRM activities will defeat its potential solution to water management challenges. The main threat for sustainable local IWRM activities is the tendency of national governments to decentralise roles and responsibilities to local governments and communities without the accompanying financial resources to enable the implementation of the local participation, investments and initiatives at local level. If this tendency could be reversed, the contribution by local IWRM towards solving management problems in the water sector will be enormous. Chapter four has provided the general case-study approach used in this study in terms of research design, data collection methods, data analysis methods, ethical consideration and limitation of the current study within the context of water resource management with a focus on groundwater management. Using geologic map, satellite images, photographs and hydrogeologic conceptual model, the following results emerged: 1) that the Upper Limphasa River catchment has fractured rock aquifer with limited permeability and storage capacity / 2) The topographic nature and north-south strikes of the lineaments explained the north-south flow direction of groundwater in the catchment / 3) The drainage system observed in the Kandoli and Kaning&rsquo / ina Mountains to the east and west of the Upper Limphasa River catchment respectively (Fig. 5.1 / Fig.5.2) formed a groundwater recharge boundary / 4) The regional faults in the same mountains (Fig. 5.1 / Fig.5.2) formed structural boundary as well as hydrogeologic boundary which controlled flow direction of the groundwater / 5) the hydrogeologic conceptual model showed the existence of the forested weathered bedrock in the upland areas of the entire catchment which formed no-flow boundary and groundwater divide thereby controlling the water flow direction downwards (Fig. 5.9) / 6) The major agricultural commercial activities existed in Lower Limphasa catchment while only subsistence farming existed in Upper Limphasa catchment. This knowledge and visualization from the map (Fig. 5.3) and conceptual model (Fig.5.9) showe interactions between upland and lowland areas and the role of physical factors in controlling groundwater flow direction in the catchment. It also provided the enlightenment on implications of socioeconomic farming activities on water management. These insights enabled this study to recommend the need for expedited implementation of holistic effective management for sustainable water utilization. <font face="Times New Roman">Using different physical factors, water scarcity indices and methodologies, this study showed that Malawi is a physically water stressed as well as an economic water scarce country. This novelty is against some literature that present Malawi as a water abundant country. Again, despite the high proportion (85%) of Malawians relying on groundwater resource, groundwater availability (storage in km 6.10) compared to other countries within SADC and Africa. Given the complexity of</font><font face="Times New Roman"> groundwater abstraction, the available groundwater for use is further reduced for Malawians who depend on such a resource for their domestic and productive livelihoods. Such insights provided the basis for discussing the need for IWRM. Although daily statistics on groundwater demand (i: 21.20 litres / 116.91 litres / 80,550.99 litres), use (ii: 16.8 litres / 92.55 litres / 63,766.95 litres) and abstracted but not used (iii: 4.4 / 24.36 / 16,784.04 litres) were relatively low per person, per household and per sub-catchment respectively, such statistics when calculated on monthly basis (i. Demand: 636 litres / 3,507.30 litres / 2,416,529.70 litres / ii.Use:504 litres / 2,776.5 litres / 1, 913, 008.5 litres iii. Abstracted but not used: 132 litres / 730 litres / 503, 521.2) / and on yearly basis (i. Demand: 7,632 litres / 42,087.6 litres / 28,998,356.4 litres / ii. Use: 6,048 litres / 33,318 litres / 22, 956, 102 litres / iii: Abstracted but not used: 1,584 litres / 8,769.6 litres / 6,042,254.4 litres) per person, per household and per sub-catchment provided huge amount of groundwater (Table 6.5). Given the limited storage capacity of fractured rock aquifer in the basement complex geology, the monthly and yearly groundwater demand and use on one hand and abstracted but not used on the other was considered enormous. With the population growth rate of 2.8 for Nkhata Bay (NSO, 2009) and the observed desire to intensify productive livelihoods activities coupled with expected negative effects of climate change, the need to implement IWRM approach for such groundwater resource in the study catchment remains imperative and is urgently needed. In addition to identifying and describing factors that explain the limited groundwater availability in the study catchment, the study developed a methodology for calculating groundwater demand, use and unused at both households and sub-catchment levels. This methodology provided step-by-step procedure for collecting data on groundwater demand and use as a tool that would improve availability of data on groundwater. Implications of such results for IWRM in similar environments were discussed. Despite<font face="Times New Roman">&nbsp / the time-consuming procedure involved in using the developed methodology, the calculations are simple and interpretation of results is easily understood among various stakeholders. Hence, such an approach is recommended for the IWRM approach which requires stakeholders from various disciplines to interact and collaborate. Nonetheless, this recommends the use of this method as its further refinement is being sought. The analysis on groundwater quality has shown that the dominant water type in the aquifers of Upper Limphasa catchment was Ca-HCO had shallow, fresh groundwater with recent recharged aquifer. Analyses on</font><font face="Times New Roman"> physicochemical parameters revealed that none of the sampled boreholes (BHs) and protected shallow dug wells (PSWs) had physical or chemical concentration levels of health concern when such levels were compared with 2008-World Health Organisation (WHO) guidelines and 2005-Malawi Bureau of Standards (MBS). Conversely, although the compliance with 2008-WHO and 2005-MBS of pathogenic bacteria (E.coli) in BHs water was 100% suggesting that water from BHs had low risk and free from bacteriological contamination, water from PSWs showed 0% compliance with 2008- WHO and 2005-MBS values implying high risk to human health. The overall assessment on risk to health classification showed that PSWs were risky sources to supply potable water, hence the need to implement strategies that protect groundwater. On the basis of such findings, the analysis in this study demonstrated the feasibility of using IWRM approach as a platform for implementing environmental and engineering interventions through education programmes to create and raise public awareness on groundwater protection and on the need for collaborative efforts to implement protective measures for their drinking water sources. The use of different analytical methods which were applied to identify the exact sources of the observed contaminants in the PSWs proved futile. Therefore, this study concluded that rolling-out PSWs either as improved or safe sources of drinking water requires further detailed investigations. However, this research recommended using rapid assessment of drinking water-quality (RADWQ) methods for assessing the quality of groundwater sources for drinking. Despite the study area being in the humid climatic region with annual rainfall above 1,000 mm, many of the physical factors were not favourable for availability of more groundwater in the aquifers. Such observation provided compelling evidence in this<font face="Times New Roman">&nbsp / study to commend the local IWRM as a proxy for the full IWRM implementation for sustainable utilization of such waters. Although institutional arrangements, water laws and water policy were found problematic to facilitate a successful implementation of full IWRM at national level in Malawi, this thesis demonstrated that local institutional arrangements, coordination among institutions, data collection efforts by local community members (active participation), self-regulation among local community committees were favourable conditions for a successful local IWRM in the Upper Limphasa River catchment. This research recommends continuation of such local participation, investment and initiatives as proxy for the full and successful IWRM beyond the study catchment. However, the observed lack of financial resource from central government to facilitates local IWRM activities were seen as counterproductive. In addition, this thesis recommended further studies which should aim at improving some observed negative implications of self-regulations on community members and the limited decentralisation elements from the Department of Water Development. Finally, one of the contributions from this study is the scientific value in using different methods to assess the quality of groundwater as presented in chapter 7. The second value is the demonstration of applying practical techniques to evaluate factors that explain the amount of groundwater storage in the aquifers that can be understood by water scientists, water users, water developers and water managers to implement IWRM collaboratively using groundwater as a showcase. The third contribution is the provision of the procedure to systematically generate data on demand (abstraction) and use of groundwater in unmetered rural areas which has the potential to guide water allocation process in the catchment. Fourthly, the thesis has provided a hydrogeologic conceptual model for the first time for Limphasa River catchment to be used as a visual tool for planning and developing management practices and addressing current water problems. Fifthly, the study has shown how local IWRM works at community level as a proxy for the full implementation of IWRM despite the absence of Catchment Management Agencies. The last contribution is the dissemination of results from this study made through publications and conference presentations as outlined in the appendix.</font></font></font></font></p> </font></font></p>

With increasing demand and pressures on groundwater resources, accurate and reliable groundwater prediction models are essential for sustainable groundwater management. Groundwater models are merely approximations of reality, and we are unable to either fully characterize or mathematically describe the true complexity of the hydrologic system; therefore, inherent in all models are varying degree of uncertainty. A robust management policy should consider uncertainties in both the imprecise nature of conceptual/numerical models and their parameters. This study addresses the critical question of whether the use of multiple conceptual models to explicitly account for conceptual model uncertainty improves the ability of the models to assist in management decisions. Twelve unique conceptual models, characterized by three alternative geological interpretations, two recharge estimations, and two boundary condition implementations, were formulated to estimate sustainable extraction rates from Thailand’s Thaphra Area, where increasing groundwater withdrawals may result in water level declination and saline water upconing. The models were developed with MODFLOW and calibrated using PEST with the same set of observed hydraulic head data. All of the models were found to reasonably produce predictions of the available heads data. To select the best among the alternative models, multiple criteria have been defined and applied to evaluate the quality of individual models. It was found that models perform differently with respect to different evaluation criteria, and that it is unlikely that a single inter-model comparison criterion will ever be sufficient for general use. The chosen alternative models were applied both individually and jointly to quantify uncertainty in the groundwater management context. Different model-averaging methods were assessed in terms of their ability to assist in quantifying uncertainty in sustainable yield estimation. The twelve groundwater simulation models were additionally linked with optimization techniques to determine appropriate groundwater abstraction rates in the TPA Phu Thok aquifer. The management models aim to obtain maximal yields while protecting water level decline. Despite similar performances among the calibrated models, total sustainable yield estimates vary substantially depending on the conceptual model used and range widely, by a factor of 0.6 in total, and by as much as a factor of 4 in each management area. The comparison results demonstrate that simple averaging achieves a better performance than formal and sophisticated averaging methods such as Maximum Likelihood Bayesian Model Averaging, and produce a similar performance to GLUE and combined-multiple criteria averaging methods for both validation testing and management applications, but is much simpler to implement and use, and computationally much less demanding. The joint assessment of parameter and conceptual model uncertainty was performed by generating the multiple realizations of random parameters from the feasible space for each calibrated model using a simple Monte Carlo approach. The multi-model averaging methods produce a higher percentage of predictive coverage than do any individual models. Using model-averaging predictions, lower optimal rates were obtained to minimize head constraint violations, which do not ensue if a single best model is used with parameter uncertainty analysis. Although accounting for all sources of uncertainty is very important in predicting environmental and management problems, the available techniques used in the literature may be too computationally demanding and, in some cases, unnecessary complex, particularly in data-poor systems. The methods presented here to account for the main sources of uncertainty provide the required practical and comprehensive uncertainty analysis and can be applied to other case studies to provide reliable and accurate predictions for groundwater management applications.

This thesis examines the history of groundwater management through the development of groundwater conservation districts in Texas. Political, economic, ideological, and scientific understandings of groundwater and its regulation varied across the state, as did the natural resource types and quantities, which created a diverse and complicated position for lawmakers and landowners. Groundwater was consistently interpreted as a private property right and case law protected unrestricted use for the majority of the twentieth-century even as groundwater resources crossed property and political boundaries, and water tables declined particularly during the second-half of the century. The case study of the Brazos Valley Groundwater Conservation District describes the complicated history of groundwater in Texas as the state attempted to balance natural resource legislation and private property rights and illuminate groundwater’s importance for the future.