Thesis (M.Sc.)--University of the Witwatersrand, Faculty of Science, 2004.

The aim of this study was to evaluate the quality of the groundwater around the Aitik copper mine- one of Europe’s largest copper mine located 15 km outside of Gällivare, Sweden - as well the placement of the groundwater pipes around the area. The study also included a survey of what kind of terms, regarding groundwater that may become relevant in the future for an activity of Aitik’s size and type. Monitoring data was analysed between the years 2014 – 2018 for the parameters; pH, SO4, Cd, Co, Cu, Zn, Ni and U. The correlation between the parameters where tested and the monitoring data where compared to the Swedish Environmental Protection Agency criteria for groundwater as well to the groundwater chemistry from a reference area nearby, Liikavaara Östra. The result of the study shows that low pH raises the mobility of the metals Cd, Co, Cu, Zn and Ni. The result also indicates that SO4, Ni and Co are higher than the reference area but that the groundwater overall shows small signs of being affected by sulphide weathering. Therefore, metals can’t be excluded from originating from high background contents. The geographic analyse shows that the groundwater pipes are well placed in compared with the water flow direction and that two of the pipes can be excluded from sampling. Future terms regarding groundwater will likely regard protective measures and quantity restrictions. Still monitoring groundwater quality is very important to control environmental impact of the activity and to prevent deterioration of quality in the future.

In order to find effective measures that meet the requirements for proper groundwater quality and quantity management, there is a need to develop a Decision Support System (DSS) and a suitable modelling tool. Central components of a DSS for groundwater management are thought to be models for surface- and groundwater flow and solute transport. The most feasible approach seems to be integration of available mathematical models, and development of a strategy for evaluation of the uncertainty propagation through these models. The physically distributed hydrological model ECOMAG has been integrated with the groundwater model MODFLOW to form a new integrated watershed modelling system - ECOFLOW. The modelling system ECOFLOW has been developed and embedded in Arc View. The multiple-scale modelling principle, combines a more detailed representation of the groundwater flow conditions with lumped watershed modelling, characterised by simplicity in model use, and a minimised number of model parameters. A Bayesian statistical downscaling procedure has also been developed and implemented in the model. This algorithm implies downscaling of the parameters used in the model, and leads to decreasing of the uncertainty level in the modelling results. The integrated model ECOFLOW has been applied to the Vemmenhög catchment, in Southern Sweden, and the Örsundaån catchment, in central Sweden. The applications demonstrated that the model is capable of simulating, with reasonable accuracy, the hydrological processes within both the agriculturally dominated watershed (Vemmenhög) and the forest dominated catchment area (Örsundaån). The results show that the ECOFLOW model adequately predicts the stream and groundwater flow distribution in these watersheds, and that the model can be used as a possible tool for simulation of surface– and groundwater processes on both local and regional scales. A chemical module ECOMAG-N has been created and tested on the Vemmenhög watershed with a highly dense drainage system and intensive fertilisation practises. The chemical module appeared to provide reliable estimates of spatial nitrate loads in the watershed. The observed and simulated nitrogen concentration values were found to be in close agreement at most of the reference points. The proposed future research includes further development of this model for contaminant transport in the surface- and ground water for point and non-point source contamination modelling. Further development of the model will be oriented towards integration of the ECOFLOW model system into a planned Decision Support System. / QC 20101007

Mogan and Eymir Lakes, located 20 km south of Ankara, are important aesthetic, recreational, and ecological resources. DikilitaS and ikizce reservoirs, constructed on upstream surface waters, are two man-made structures in the basin encompassing an area of 985 km2. The purpose of this study is (1) to quantify groundwater components in lakes&rsquo / budgets, (2) to assess the potential impacts of upstream reservoirs on lake levels, and (3) to determine effects of potential climatic change on lakes and groundwater levels in the basin. Available data have been used to develop a conceptual model of the system. The three dimensional groundwater model (MODFLOW) has been developed for the system. The model has been calibrated successfully under transient conditions over a period of six years using monthly periods. The results show that groundwater inflows and outflows have the lowest contribution to the overall lakes&rsquo / budget. A sensitivity analysis was conducted to determine the limits within which the regional parameters may vary. Three groundwater management scenarios had been developed. The results show that the upstream reservoirs have a significant effect on lake stages but not on groundwater levels. A trade-off curve between the amount of water released and the average stage in Lake Mogan has been developed. The continuation of the existing average conditions shows that there would be declines in groundwater elevations in areas upstream from Lake Mogan and downstream from Lake Eymir. The results also indicated that very small, but long-term changes to precipitation and temperature have the potential to cause significant declines in groundwater and lake levels.

The purpose of this study is the characterization and modeling of Ulubey aquifer system which serves as an important water supply for USak province located in inner parts of the Aegean Region in Turkey. In recent years, growing population, accelarating industrial activities and on the contrary decreasing rainfall and contamination of the surface water resources made groundwater indispensable to meet domestic, agricultural and industrial water demands of USak province. All these facts necessitate the development of a groundwater management plan, which this study aims to end up with. For this purpose, every single component of the recharge/discharge mechanisms of the groundwater budget of the aquifer system should conceptually be comprehended. However, due to lack of data, all of the components can not be precisely determined. Hence, a mathematical groundwater flow model successfully calibrated under steady state conditions, is utilized to calculate the missing components of the groundwater budget and also to test the effects of increased pumping rates for irrigational and domestic uses to supply the increasing demand in the future. For this purpose, three management scenarios are set up under transient conditions over a planning period of 20 years. Drawdown maps, groundwater budgets and groundwater level hydrographs are utilized to observe the effects. The results of these simulations proved that neither of the tested management scenarios creates significant drawdowns or change in groundwater reserve of the Ulubey aquifer system.

<p>The aim of this investigation was to provide a framework or strategy for prioritising and implementing regional groundwater monitoring in the Olifants-Doorn Water Management (WMA) area. The general approach was to attempt to reconcile monitoring requirements with existing resources, while investigating the hypothesis that regional monitoring should focus on resource status monitoring. Groundwater science needs to focus on clarifying the sustainability options available to the stakeholders, and monitoring the chosen option. This can best be done by adopting an adaptive management approach to both the management of the groundwater resources, and the management of the monitoring programme.</p>

La gestion durable des aquifères est une problématique grandissante depuis la fin du 20ème siècle. L'exploitation d’une ressource en eau souterraine est qualifiée de durable lorsque la capture des flux environnementaux est considérée comme acceptable sur le long terme. La modélisation hydrodynamique s'impose comme un outil indispensable pour remplacer une gestion réactive par une approche anticipative. Les paramètres hydrodynamiques qui caractérisent un aquifère et contrôlent les variables de sorties des modèles hydrodynamiques sont souvent mal connus. L’estimation de ces paramètres par la modélisation inverse souffre de la non-unicité de la solution optimale. Une approche simplifiée pour la quantification des incertitudes (analyse linéaire) est présentée comme une alternative pragmatique à des méthodes stochastiques inapplicables pour des modèles opérationnels. A partir de la réalisation d’une station expérimentale pilote, différentes méthodes (parfois complémentaires) ont été évaluées pour contraindre la recharge météorique et les propriétés hydrauliques d’un aquifère afin de réduire l’incertitude prédictive. La réalisation d’un modèle vertical couplé sol-surface a permis de démontrer que, dans le contexte étudié, la tension matricielle apporte suffisamment d’informations afin de contraindre la recharge prédite. Une interprétation conjointe d’un essai de nappe libre et des fluctuations piézométriques a permis une estimation intégrée de la recharge et des paramètres hydrodynamiques de la nappe libre. Ce travail de thèse a ainsi permis (i) de démontrer l’intérêt de disposer de méthodes algorithmiques pour la calibration et la quantification des incertitudes paramétriques pour un modèle hydrodynamique de gestion ; (ii) de mener une réflexion méthodologique sur l’utilisation de méthodes existantes afin d’apporter de l’information complémentaire fiable sur les paramètres hydrodynamiques ainsi que sur la recharge météorique. Ce travail offre des perspectives quant à la mise en place d’un réseau de suivi complet à l’échelle d’un bassin hydrogéologique. / The sustainable management of aquifers is a growing problem since the end of the 20th century. For groundwater withdrawals to be considered as sustainable, the capture of environmental flow should remain acceptable over a long-term period. Groundwater modeling is an essential tool to move from a reactive management to an anticipatory approach. Hydrodynamic parameters characterizing the aquifers are often poorly constrained by prior information or history matching. The estimation of these parameters by inverse modeling suffers from the non-uniqueness of the solution. This is an issue when predicted values by groundwater model are used to define legal frameworks. A simplified approach for the quantification of uncertainties (linear analysis) is presented as a pragmatic alternative to stochastic methods that cannot be applied to operational groundwater management models. The implementation of a pilot experimental station brings possibility to evaluate different approaches for the estimate of groundwater recharge and hydrodynamic parameters estimation in order to reduce the uncertainty of groundwater management models. A 1D coupled soil-surface model was used to demonstrate that, in the studied context, matrix potential measurements alone appear as sufficient to constrain coupled model-based estimates of recharge. In addition, a joint interpretation of an unconfined aquifer-test and water table fluctuations has been conducted. Reliable estimates of groundwater recharge can be obtained from water level records when considering long recharge events and a consistent value of drainable porosity. This thesis highlights (i) the necessity to use algorithmic methods for parameters estimation and uncertainty quantification for a groundwater management model; (ii) the interest of different methods to collect reliable hydrodynamic parameters and groundwater recharge estimation. This work can be used to support a monitoring network for parameters estimation at a basin scale.

Stakeholder participation is a foundation of good water governance. Good groundwater governance typically involves the co-production of knowledge about the groundwater system. Models provide a vehicle for producing this knowledge, as well as a boundary object around which scientists and stakeholders can convene the co-production process. Through co-production, stakeholders and scientific experts can engage in exchanges that create system knowledge not otherwise achievable. The process involves one-way transfer of information, active two-way conversations, and integration of multiple kinds of knowledge into shared understanding. In the Upper Santa Cruz River basin in Arizona, USA, the University of Arizona Water Resources Research Center (WRRC) convened a project aimed at providing scientific underpinnings for groundwater planning and management. This project, entitled Groundwater, Climate, and Stakeholder Engagement, serves as a case study employing the first two stages of knowledge co-production using a hydrological model. Through an iterative process that included two-way communication, stakeholders provided critical input to hydrologic modeling analyses. Acting as a bridging organization, the WRRC facilitated a co-production process, involving location-specific and transferability workshops, which resulted in new knowledge and capacity for applying the model to novel problems.

Agriculture in California’s Central Valley is important to the US economy and food supply. High reliance on groundwater (GW) for irrigation has led to GW overdraft. Among the consequences is that the GW level is lowered, increasing the energy requirements and cost of GW extraction. This is assessed in a case study of the Turlock subbasin, as well as a simplified Cost-Benefit Analysis (CBA), in which the profitability of strategies for avoiding groundwater overdraft is compared to Business As Usual (BAU) for the years 2001 and 2050, using a high and low energy cost estimate. Climate projections are applied to the year 2050. An overdraft of 95 million m3 in 2001 is found to lower the GW level by 19.3cm, leading to an increase in energy requirements and cost of GW extraction of 0.320 Wh/m3 and 0.416 cents/m3, respectively. A reduction in production was found to be less profitable than BAU in all cases except for the year 2050, using high cost estimates. Crop replacement was found to be profitable in all cases. The use of desalinated water was found to be unprofitable in all cases. It is concluded that climate change and irrigation costs will have one or more of the following outcomes: decreased production, a shift towards higher $/m3 crops, and/or increased food prices. / Lantbruk I Kaliforniens Central Valley region är viktig för den Amerikanska ekonomin och livsmedelsförsörjningen. Stort beroende av grundvatten till konstbevattning har lett till grundvatten-övertrassering. Bland dess konsekvenser är att grundvatten nivån sjunker, vilket gör det mer energi-krävande och kostsamt att pumpa grundvattnet. Detta analyseras i fallstudiet, Turlock subbasin, där det även utförs en förenklad kostnads-nytto analys, i vilken lönsamheten av strategier för att undvika grundvatten-övertrassering jämförs med Business As Usual (BAU) för åren 2001 och 2050, baserad på en hög och en låg uppskattning av energi kostnader. Året 2050 beräknas inklusive förväntade förändringar i klimatet. En övertrassering på 95 miljoner m3 i 2001 visar sig resultera i att grundvatten nivån sjunker 19,3 cm, vilket ökar energibehovet och kostnaden av att pumpa grundvatten med 0,32 Wh/m3 respektivt 0,416 cents/m3. Att minska produktionen visar sig att endast vara lönsamt i ett fall: år 2050 med höga energi uppskattningar. Att byta grödor visar sig vara lönsamt i alla fall. Att förbruka desalinerat vatten visar sig vara olönsamt i alla fall. Det dras slutsatsen att förändringar i klimatet och kostnader av konstbevattning kommer att leda till en eller fler av följande utfall: förminskad produktion, ett skift mot högre $/m3 grödor, och/eller förhöjda matpriser.

Thesis (MScAgric (Agricultural Economics)--University of Stellenbosch, 2009. / This thesis constitutes a socio-economic study that centres on determining the economic value of groundwater in rural and agricultural uses. Limpopo Water Management Area (WMA1) and Luvuvhu/Letaba Water Management Area (WMA2) were studied in this thesis. In WMA1 table potato irrigation in the Polokwane agricultural area was studied, while Gaphago, Leokaneng, Kanana and Mohlajeng villages were studied for rural household groundwater use. In WMA2 tomato irrigation in the Mooketsi agricultural area was studied, while Lemondokop, Sereni and Hamashamba villages were studied for rural household groundwater use. Scoping field trips to the study area as well as secondary data revealed that groundwater was the dominant water source in all these selected study epicentres. In the Polokwane agricultural area, the farms typically relied on numerous boreholes. In the Mooketsi commercial farming area, groundwater was the dominant water source for most years, except when flush floods replenished farm dams. When flush floods occurred, farmers partially substituted surface water for groundwater because of economic reasons. This study determined the economic value of groundwater in two use sectors. First, determining the utility value of groundwater in selected rural households using the contingent valuation method. Utility value was defined by Dupuit (1844) and Marshall (1879) as the maximum sacrifice expressed in money terms which each consumer would be willing to make in order to acquire an object. Open-ended questions were used to determine willingness to pay during contingent household groundwater valuation. The overall mean willingness to pay for satisfactory household groundwater for the study area was R2.28 per kilolitre of groundwater.