Spelling suggestions: "subject:"ecohydrology."" "subject:"paleohydrology.""
21 |
Modelling of Fluid Flow and Contaminant Transport in Fractured Rock : Case Study / Modellering av flöden och transport av föroreningar i bergsprickor : FältstudiePegestam, Ebba January 2022 (has links)
Drinking water contamination is a big concern in Sweden and is commonly traced back to being waste from former manufacturing industrial sites. Pollutants in the topsoil can be remediated by several techniques, such as decontamination or excavation but the toxins already enclosed in the bedrock cannot be treated the same and is harder to track possible contaminant pathways. To gain knowledge of modelling fluid flow and solute transport in the bedrock is therefore highly crucial to detect any safety risks. Not only for drinking water safety but also to understand possible reservoir storage or to store disposals from radioactive waste. For this study, high levels of chlorinated solvents have been measured at a former industrial plant manufacturing electronic products, where the prominent chemicals are PCE and its degradation products. The soil will be remediated from the site, but the remaining question is if the contaminants can be further transported in the bedrock fractures to a drinking water source for the municipality. The lake is located approximately 4km from the site and will take too much time and computational effort to run the model. Instead, this study will focus on a small-scale model estimating a suitable distance from the source where additional boreholes can be placed. The model will have a size of 455 x 436 x 38m and the study will be divided into three main tasks; improve understanding of the fracture geometry by statistical analyses of the measured fractures in the study area, build and run a groundwater flow model representing the study area, investigate possible pathways of contaminant transport in the fracture networks and analyze the impact of geological features. The methodology is divided into several parts. First, statistical analyses of the fractures will be done using the software FracMan version 8.0, which will act as a foundation of the DFN model. Next part includes calibration of the model and generation of fracture network based on the statistical analysis. The last part includes flow and transport simulations using the application Pflotran within FracMan version 8.1. The results shows that large fracture zones affect the flow to a great extent and therefore also control the transport of contaminants in the bedrock. Because of uncertainties regarding size of the zones, additional boreholes should be placed upon their respective orientations close to the already existing boreholes to investigate their characteristics. It is also necessary to place additional boreholes randomly within the study model to detect other fracture zones and possible dominant fracture sets. The additional boreholes should be deeper than the existing ones to detect possible fracture networks further down in the bedrock. Contaminant pathways are hard to establish because of the deterministic zones that determines the flow. The scenario where no zones were included, two dominant pathways are visible, one on the upper part and one in the lower part of the model. The scenario where zones were included, one dominant pathway is visible, following the large fracture zone reaching from one borehole towards the outlet boundary. In conclusion, these results highlight the importance of doing more measurements to strengthen the basis for evaluation of pollutant transport to the nearby lake. Because of the risk of poisoning the drinking water, it is extremely important to be able to make a realistic model for contaminant transport. Since the results of flow simulations differs between different input transmissivities, next step should be to do hydraulic tests in the already existing boreholes to establish the local transmissivity for the fractures. After that, additional boreholes in the field, both on top of the measured zones close to the existing boreholes as well as boreholes randomly throughout the study area should be placed. / Rent dricksvatten är en angelägenhet för alla i Sverige och för att säkerhetsställa rent dricksvatten krävs förebyggande åtgärder som kan förhindra att föroreningar tar sig till dricksvattenkällor. Dessa åtgärder kan bland annat innehålla mätningar för att spåra föroreningens ursprung och transportvägar. Ursprungen kan oftast kopplas till avfall från gamla tillverkningsindustrier. Föroreningar som spåras till matjorden kan åtgärdas genom sanering eller schaktning medan föroreningar som tagit sig ner i berggrunden inte kan behandlas på samma sätt. Föroreningars transport genom sprickor är svåra att spåra och lokalisera på grund av oförutsägbara förhållanden med olika bergarter, kvalitéer, sprickstorlek etcetera. På grund av detta är det viktigt att kunna modellera flöden och transport av lösa ämnen för att förhindra hälso-och säkerhetsrisker. Modellering av spricksystem är även viktigt för att undersöka framtidens energiextraktion från geotermisk aktivitet, eller att kunna lagra avfall från radioaktiva ämnen. Denna studie görs då det har mätts upp höga nivåer av klorerade lösningsmedel från en gammal fabrik som tillverkat elektronikprodukter, främst kemikalierna PCE och dess nedbrytningsprodukter. Mätningar har gjorts på platsen i form av tre borrningar och bergkartering. Föroreningar i jordmånen kommer att åtgärdas men den kvarstående funderingen är om de föroreningarna som redan tagit sig ner i berggrunden, kan transporteras genom spricknätverket fram till en sjö som kommunen använder som dricksvattenkälla. Sjön är lokaliserad ungefär fyra kilometer från den gamla anläggningen och på grund av den långa distansen kommer det krävas mycket lagring och beräkningskraft av den använda datorn. För att undvika detta, kommer denna studie i stället fokusera på en småskalig modell med den ungefärliga storleken 455 x 436 x 38m där syftet är att uppskatta var nya borrningar kan göras för att få fram mer information angående potentiella föroreningar och dess flyktvägar. Denna studie kommer vara uppdelad i tre huvudsakliga syften; göra statistiska analyser av data som samlats in från fält, bygga upp och köra en grundvattenmodell som representerar studieområdet, undersöka potentiella vägar för transport av föroreningar i spricksystemet samt analysera dess påverkan av geologiska egenskaper. För denna studie har metoden delats upp i flera steg. Det första steget innehåller statistiska analyser av sprickorna i området som kommer utgöra grundinformationen för spricknätverket. Detta görs i programmet FracMan version 8.0. Nästa del innehåller kalibrering av modellen samt flödes- och transportsimuleringar genom applikationen Pflotran som är installerat i FracMan version 8.1. Resultatet av flödes- och transportsimuleringarna visar att stora sprickzoner påverkar flödet i stor utsträckning och kontrollerar därför transporten av föroreningar. Storleken av sprickzonerna är svåra att bedöma då det inte finns någon mer information än det som mätts i borrhålet, där den minsta storleken är av borrhålets radie. På grund av detta lades zonerna in deterministiskt med en radie lika stor som modellen. Detta medför att resultaten över transporteringsvägar är högst bestämmande av zonerna där zonen som går mot utflödesgränsen agerar som en motorväg för föroreningar medan zonen som går mot en gräns utan utflöde agerar likt en sjö, vilket gör att partiklarna som hamnar i zonen stannar där och kan inte ta sig därifrån och fortsätta transporten. På grund av denna osäkerhet kring storleken för zonerna bör det placeras ytligare borrhål längs med orienteringen av sprickorna max 10 meter från de existerande borrhålen för att se om zonerna fortsätter eller blivit avkapade. Eftersom inga hydrauliska tester gjorts i borrhålen är det ett viktigt nästa steg för att bestämma rätt transmissivitet i sprickorna. Det är möjligt att det finns fler zoner inom området som kan bestämma flödesvägar, därför är det också viktigt att placera ut fler borrhål slumpmässigt inom området för att upptäcka fler zoner eller andra dominerande sprickorienteringar än de som hittills mätts. Alla nya borrhål bör även gå djupare än de som redan finns för att kunna upptäcka andra eventuella spricknätverk djupare ner i berggrunden. På grund av risken att kontaminera dricksvattnet är det otroligt viktigt att kunna göra en realistisk modell som representerar transporten av föroreningar. Fortsatt arbete bör därför prioritera hydrauliska tester för att bestämma transmissiviteten i spricknätverket, därefter utföra fler och djupare borrhål i området för att undersöka andra potentiella deformationer.
|
22 |
The management of potable water supply in Mogwase Township, Moses Kotane Local Municipality / Daniel Kagiso MosimeMosime, Daniel Kagiso January 2014 (has links)
The continuous population growth and the notable development of the mining industry have resulted in challenges for potable water supply in South Africa. The ever-increasing number of people migrating to urban areas has resulted in the demand of potable water supply in South Africa. Water is regarded as a human basic right which is promulgated by the recent amendment of the potable water service provisioning Water Services Act 108 of 1997 and the National Water Act 36 of 1998. The afore-mentioned Acts started a process to address the imbalance that existed during the apartheid regime. (The apartheid regime essentially had one objective initially, namely the control of (black, coloured and Indian) people in order to protect white privilege). It was meant to separate people of different races).The Acts were formulated to address the equal distribution of national resource for all South Africans.
Mogwase Township in Moses Kotane Local Municipality is undergoing continuous growth with several mining areas being developed. Consequently, the supply of potable water has been a challenge in the area. It is, therefore, in the interest of the researcher to investigate the management of potable water supply in Mogwase Township with the aim of suggesting improved service delivery by the Moses Kotane Local Municipality.
Water is now recognised as a scarce resource that belongs to all South Africans. The provision of potable water by the water services authorities (WSAs) is an important basic service that faces a number of challenges, such as the use of outdated infrastructure, namely: pipelines from the Vaalkop Dam, the lack of skilled and knowledgeable people, improper planning, and the booming population that place overt pressure on the demand for effective and efficient service delivery.
This research was undertaken to investigate how Moses Kotane Local Municipality which obtains its potable water supply from Vaalkop Dam can improve the supply of water in a more effective, efficient, equitable, economic and sustainable manner through improved co-operative governance and integrated water resource management (IWRM).
The qualitative and quantitative research designs were used to conduct the research, which included a literature review, semi-structured interviews, data sampling and scientific analysis of the responses.
The researcher arrived at logical conclusions and S.M.A.R.T. (Simple, Measureable, and Achievable Realistic Timebound) recommendations with regard to all aspects related to the future management of potable water supply in Mogwase Township. / MA (Development and Management), North-West University, Potchefstroom Campus, 2015
|
23 |
The management of potable water supply in Mogwase Township, Moses Kotane Local Municipality / Daniel Kagiso MosimeMosime, Daniel Kagiso January 2014 (has links)
The continuous population growth and the notable development of the mining industry have resulted in challenges for potable water supply in South Africa. The ever-increasing number of people migrating to urban areas has resulted in the demand of potable water supply in South Africa. Water is regarded as a human basic right which is promulgated by the recent amendment of the potable water service provisioning Water Services Act 108 of 1997 and the National Water Act 36 of 1998. The afore-mentioned Acts started a process to address the imbalance that existed during the apartheid regime. (The apartheid regime essentially had one objective initially, namely the control of (black, coloured and Indian) people in order to protect white privilege). It was meant to separate people of different races).The Acts were formulated to address the equal distribution of national resource for all South Africans.
Mogwase Township in Moses Kotane Local Municipality is undergoing continuous growth with several mining areas being developed. Consequently, the supply of potable water has been a challenge in the area. It is, therefore, in the interest of the researcher to investigate the management of potable water supply in Mogwase Township with the aim of suggesting improved service delivery by the Moses Kotane Local Municipality.
Water is now recognised as a scarce resource that belongs to all South Africans. The provision of potable water by the water services authorities (WSAs) is an important basic service that faces a number of challenges, such as the use of outdated infrastructure, namely: pipelines from the Vaalkop Dam, the lack of skilled and knowledgeable people, improper planning, and the booming population that place overt pressure on the demand for effective and efficient service delivery.
This research was undertaken to investigate how Moses Kotane Local Municipality which obtains its potable water supply from Vaalkop Dam can improve the supply of water in a more effective, efficient, equitable, economic and sustainable manner through improved co-operative governance and integrated water resource management (IWRM).
The qualitative and quantitative research designs were used to conduct the research, which included a literature review, semi-structured interviews, data sampling and scientific analysis of the responses.
The researcher arrived at logical conclusions and S.M.A.R.T. (Simple, Measureable, and Achievable Realistic Timebound) recommendations with regard to all aspects related to the future management of potable water supply in Mogwase Township. / MA (Development and Management), North-West University, Potchefstroom Campus, 2015
|
24 |
The management of potable water supply in Khuma Township, Matlosana Local Municipality / Kagisho Simon MonnahelaMonnahela, Kagisho Simon January 2014 (has links)
The birth of a non-racial democracy in South Africa brought many challenges such as the supply of potable water to all societies irrespective of their colour or even location. Migration of people from rural to urban has increased the demand of potable water supply in many areas that were previously neglected by the former Apartheid regime. The increase of the human population in urban or developing areas of South Africa will therefore imply that various public services such as potable water supply, proper housing, electricity supply, schooling and basic health facilities should be provided in an efficient, effective and economic manner.
As the resident of Khuma Township, the researcher has a keen interest in the management of potable water supply in this area, inter alia, the nature and extent of the physical environment and the efficiency and effectiveness of a potable water supply as a means of improving service delivery by the Matlosana Local Municipality to Khuma Township. The area has the history of gold mining and the majority of the people from other rural areas and neighbouring states moved into this area and were later joined by their families. This resulted in an increase in the population to a point where people were placed in dangerous areas such as underlying dolomite and along the Koekemoer spruit. For example, extension 6 is known to experience sinkholes due to underground mining activities and the underline dolomite rock.
The population has increased in Khuma Township to such an extent that a shortage of potable water supply is been experienced. Khuma Township had one water reservoir for the past 40 years and Matlosana Local Municipality did not improve or developed infrastructure related to potable water supply to be able to cater for the increasing population of this area.
An empirical study was conducted in among the residents of Khuma Township, Matlosana Local Municipality and role-players in the management of potable water supply. From this study, it was evident that the supply of potable water in Khuma Township is insufficient, and there was poor communication, cooperation and participation between Matlosana Local Municipality and the residents of Khuma Township. The ineffective management of potable water supply in Khuma Township by the Matlosana Local Municipality as well as ignoring the significance of settling people in a safe area that is free from water pollution, sinkholes and underlying dolomite rock left a lot to be desired.
The researcher arrived at logical conclusions and recommendations with regard to all aspects related to future management of potable water supply in Khuma Township. / M Development and Management, North-West University, Potchefstroom Campus, 2014
|
25 |
The management of potable water supply in Khuma Township, Matlosana Local Municipality / Kagisho Simon MonnahelaMonnahela, Kagisho Simon January 2014 (has links)
The birth of a non-racial democracy in South Africa brought many challenges such as the supply of potable water to all societies irrespective of their colour or even location. Migration of people from rural to urban has increased the demand of potable water supply in many areas that were previously neglected by the former Apartheid regime. The increase of the human population in urban or developing areas of South Africa will therefore imply that various public services such as potable water supply, proper housing, electricity supply, schooling and basic health facilities should be provided in an efficient, effective and economic manner.
As the resident of Khuma Township, the researcher has a keen interest in the management of potable water supply in this area, inter alia, the nature and extent of the physical environment and the efficiency and effectiveness of a potable water supply as a means of improving service delivery by the Matlosana Local Municipality to Khuma Township. The area has the history of gold mining and the majority of the people from other rural areas and neighbouring states moved into this area and were later joined by their families. This resulted in an increase in the population to a point where people were placed in dangerous areas such as underlying dolomite and along the Koekemoer spruit. For example, extension 6 is known to experience sinkholes due to underground mining activities and the underline dolomite rock.
The population has increased in Khuma Township to such an extent that a shortage of potable water supply is been experienced. Khuma Township had one water reservoir for the past 40 years and Matlosana Local Municipality did not improve or developed infrastructure related to potable water supply to be able to cater for the increasing population of this area.
An empirical study was conducted in among the residents of Khuma Township, Matlosana Local Municipality and role-players in the management of potable water supply. From this study, it was evident that the supply of potable water in Khuma Township is insufficient, and there was poor communication, cooperation and participation between Matlosana Local Municipality and the residents of Khuma Township. The ineffective management of potable water supply in Khuma Township by the Matlosana Local Municipality as well as ignoring the significance of settling people in a safe area that is free from water pollution, sinkholes and underlying dolomite rock left a lot to be desired.
The researcher arrived at logical conclusions and recommendations with regard to all aspects related to future management of potable water supply in Khuma Township. / M Development and Management, North-West University, Potchefstroom Campus, 2014
|
26 |
NCMA Groundwater Model Using USGS MODFLOW-2005/PESTWallace, Brian Matthew 01 June 2016 (has links) (PDF)
A numerical model for the NCMA aquifer complex is presented. The objective of the study is to develop a numerical groundwater model for the NCMA aquifer system to enhance the understanding of subsurface groundwater flow. Infiltration, streamflow, pumping, and return flows are implemented to characterize the aquifer complex over time. The numerical model is calibrated to municipal and monitoring well data, average monthly water balances, and hydraulic contours. Transient aquifer inflows and outflows are assessed in the results of the study and are compared to balance terms from previous studies. The 2007 Todd Engineers Study subsurface inflows and outflows generate well hydrographs that have greater heads than observed data. Calibration to well hydrographs generated increased subsurface outflow values and decreased subsurface inflow values. It is possible that approximately 250 AFY is leaving aquifer storage.
|
Page generated in 0.0531 seconds