[pt] A água de um aquífero não é totalmente pura, ela contém substâncias constituintes dissolvidas como sulfatos e cloretos, líquidos e constituintes orgânicos, inorgânicos dissolvidos e patógenos. É importante a remediação da água contaminada com o controle ou remoção da fonte de contaminação, evitando a contínua propagação do poluente no aquífero. A captura da pluma de contaminação pode ser realizada com poços de bombeamento, formando zonas de captura, impedindo sua propagação para áreas limpas e removendo o poluente. Esta extração deve ser com o menor volume de água possível pois esta deverá ser descontaminada e utilizada ou descartada. Tendo esta direção de pesquisa, este trabalho baseia-se no desenvolvimento de um software, que possa simular o fluxo de água em um aquífero confinado e a formação de zonas de captura para a extração de poluentes por poços; na investigação de diferentes operações de bombeamento minimizando as zonas de estagnação. O software desenvolvido utiliza elementos finitos 2d; variação no tempo das condições de fluxo monofásico; obtém a solução no tempo pelo método da integração temporal. Os estudos numéricos consideraram o aquífero homogêneo ou heterogêneo e isotrópico, e o fluxo de água segue a lei de Darcy. Foram analisadas zonas de captura sob diferentes condições hidrogeológicas; com poços em diferentes posições, com diferentes vazões e com bombeamento constante e; a utilização de poços de injeção reinjetando água extraída. Foi constatado que a modelagem numérica é importante na avaliação de estratégias de bombeamento. / [en] The aquifer water is not totally pure, it contains dissolved constituents from natural solids sources such as sulfates and chlorides. Also, there are organic liquids, organic and inorganic constituents dissolved or pathogens from an anthropogenic source. It is important the contaminated water remediation with the control or removal of the source of contamination, avoiding the continuous propagation of the contamination plume in the aquifer and the reduction of contaminant concentration levels. Control and capture of the contamination plume can be done by pumping wells positioned at the edge of the plume, forming the capture zones to prevent the plume propagation to the not contaminated areas and to remove the pollutant from the aquifer. This extraction should be with a few water volumes, as this should be decontaminated and used or discarded. With this research direction, this work is based on the development of a software to simulate the water flow in a confined aquifer and the formation of the capture zone by pumping wells. Also, it is based on the investigation of different pumping operation features to maximize the contaminant extraction with the minimizing of the withdrawn water volume. The developed software uses bi and three-dimensional finite elements; time variation of monophasic flow conditions; obtains the solution in time by the method of direct temporal integration. The numerical studies considered homogeneous or heterogeneous and isotropic aquifer, and the groundwater flow follows Darcy s law. The formation of the capture zone under different hydrogeological conditions was analyzed; also, with pupping wells in different positions, with different flows conditions and with constant pumping and; the use of injection wells reinjecting extracted water. It was verified that the numerical modeling is important to the evaluation of pumping strategies that provide the greatest removal of solute mass with the lowest water volume extraction.

Grundvatten finns över allt i marken och vid byggnation under markytan är det därför viktigt att tagrundvattnets påverkan i beaktning för att inte skada miljö eller närområde. Hur en lokalgrundvattenstörning sprids i närområdet är normalt svårbedömt, och modelleringsverktyg har blivit ett vanligt verktyg för att undersöka flöden och potentiell påverkan på grundvatten. I detta arbete utvecklasen grundvattenmodell i ModelMuse med Modflow 6 för att undersöka påverkansområdet för en planeradbyggnation som kräver en grundvattensänkning, i Veddesta, Järfälla kommun. Arbetet syftar även tillatt bedöma de olika parametrar som krävs för modelleringen och hur de kan mätas eller uppskattas. Inför modelleringen undersöktes akviferens egenskaper med slugtester och ett kort pumpningstestoch tidigare undersökningar användes för att skapa modellens lagerföljd. Modellen använde tre lager,som generellt från ytan representerade lera, friktionsjord (morän) samt ett berglager, där domänenbestämdes utifrån ett avgränsat avrinningsområde. Modellen kalibrerades manuellt mot observationer i flera grundvattenrör kring byggnationsområdet.För övriga delar av modellen gjordes endast en grov värdering av grundvattennivåerna, där vissa oklaranivåer kvarstod under vidare modellering. Den avsänkning som modelleras uppgår som mest till 3,3 m,medan grundvattenobservationer visar att avsänkningen endast bör uppgå till 1,8 m vid samma punkt.Denna avsänkning resulterar i en omfattande och kraftig påverkan över ett stort område, men denmodellerade påverkan är troligen överdriven då den ursprungliga grundvattensänkningen haröverskattats. Den modellerade grundvattenpåverkan riskera att skapa sättningar och skada byggnader inom ettstort område, men dess effekter kan kraftigt minskas om avsänkningen görs inom en vattentät spont. En enklare känslighetsanalys över parametrarna som använts visar att akvifertjockleken har stor påverkanpå det beräknade utloppet för att upprätthålla avsänkningen, men relationen till påverkansområdetsstorlek är mindre tydligt. Andra betydande osäkerheter finns inom den modelleradegrundvattenbildningen samt det avrinningsområde som användes som rand. Detta arbete visar på hur de mest kritiska parametrarna för grundvatten kan bestämmas eller väljasoch hur de påverkar resultatet. Arbetet belyser också riskerna med felaktiga värden, som trots att de kananses rimliga utifrån teorin inte är lämpliga vid modellering i tätbebyggda områden. Stora avvikelserfrån de initiala värden upptäcktes för grundvattenbildning och problem relaterade tillavrinningsområdet, som upptäcktes under modellens kalibrering. / Groundwater is found everywhere in the ground and when building below ground level, the groundwatermust be considered. Failure to do so may result in damage the environment by reducing wateravailability for vegetation, nearby structures through reduced ground stability or endanger drinkingwater resources. Groundwater is difficult to assess as it can only be directly observed throughobservation wells, and digital modelling tools have become a common tool for investigating flows andpotential impacts on groundwater. In this work, a groundwater model is being developed in ModelMusewith Modflow 6 to investigate the effective influence area for a planned construction in Veddesta,Järfälla municipality in Sweden. During this construction, the groundwater levels will be loweredtemporarily to enable excavation and construction below the natural groundwater level The work alsoaims to assess the various parameters required for the modelling and how they can be retrieved. Prior to the modelling, the properties of the aquifer, which is where the main groundwater transportoccurs, were examined with slug tests and a short pumping test. Data from previous investigations wereused to create the model's stratigraphy. The model used three layers, which generally represented clay,granular soil (till) and a thin rock layer and the model’s boundary was set based on an estimatedcatchment area.    The model was manually calibrated against observations in several groundwater pipes around theconstruction area. For other parts of the model, only a rough assessment was made of the groundwaterlevels, where areas of unclear pressure heads remained throughout the modelling. The modelledlowering of the groundwater amounts to 3.3 m, while groundwater observations show that the expectedlowering should be 1.8 m. The modelled displacement results in a widespread and significant impact,but the modelled impact is probably excessive as the initial lowering of the groundwater is larger thanwhat would be necessary during the construction. The modelled displacement of groundwater risks creating subsidence which will likely damagebuildings within a large area. The impact can be greatly reduced if the lowering of groundwater is donewithin a waterproof sheet pile, which enables dewatering within the excavation without effecting thesurroundings. A simple sensitivity analysis of the parameters used in the modelling shows that theaquifer thickness has a large impact on the calculated outlet across the model boundary, which representsthe required pumping to maintain the reduced groundwater level. The relation to the size of the effectiveinfluence area is less clear. Other significant uncertainties exist within the modelled groundwaterrecharge and the catchment area that was used as the model’s boundary. This work has shown how the most significant parameters for groundwater modelling can bedetermined or selected and how they affect the result. The work also highlights the risks of incorrectvalues, which, although they can be considered reasonable based on theory may not be suitable formodelling groundwater within built up area. Notable deviations from the initial values were rechargerate and issues related to the model domain, which were discovered during the calibration process.