Il est communément admis que la recharge des aquifères carbonatés est contrôlée par la zone non saturée, siège d’une mise à l’équilibre des phases liquides, solides et gazeuses. L’épikarst, zone superficielle de ces aquifères, recueille les pluies efficaces et les transfère en profondeur via une double porosité de fissure et de fracture. Des épandages détritiques sablo-argileux fossilisent souvent les paléo-reliefs, changeant ainsi les caractéristiques des zones d’infiltration. Toutefois, les données sur ces dépôts superficiels sont rares, et leur impact sur les modalités de recharge en contexte karstique est aujourd’hui mal connu et peu décrit.La célèbre grotte préhistorique ornée de Lascaux offre une fenêtre d’observation à l’intérieur de l’épikarst et constitue ainsi un site privilégié pour le suivi des processus de transferts. La grotte fait partie d’un réseau karstique fossile partiellement comblé par du matériel détritique sablo-argileux. Les parties basses de la cavité montrent des fortes teneurs en CO2 dans l’air, supérieures à 8% (80 000 ppmv) lors de certaines périodes estivales. Cette thèse propose une étude des caractéristiques de l’infiltration en milieu karstique grâce au suivi des variations chimiques et isotopiques d’une émergence épikarstique au plafond de l’entrée de la grotte. Les principaux objectifs sont la compréhension de la dynamique des fluides en transit dans l’épikarst, la recherche de la source des fortes teneurs en CO2 ainsi que la détermination du rôle des épandages détritiques dans les modalités de recharge de l’aquifère karstique.Après avoir mener une étude approfondie de l’environnement géologique et géomorphologique du site, l’analyse hydroclimatique, combinée au suivi bimensuel de la chimie et des variations isotopiques des eaux épikarstiques, a permis d’investiguer le fonctionnement de la zone d’infiltration du karst d’un point de vue des transferts de masse.Les premières observations montrent que l’émergence épikarstique n’est pas pérenne avec un tarissement qui débute au début de l’été. Le système nécessite environ 250 mm de recharge automnale pour se réactiver. Le signal 18O à l’émergence est fortement amorti comparé au signal 18O dans les pluies ce qui démontre la création d’une réserve épikarstique qui conduit à l’homogénéisation chimique des eaux. Ainsi, les transferts de masse sont lents dans ce système caractérisé par un comportement de type fissuré et non karstique. Les données de 13C collectées à l’émergence permettent de retracer les conditions physico-chimiques qu’ont rencontrées les eaux au cours de leur transit. Elles montrent différentes origines possible de l’infiltration et révèlent des phénomènes de dégazage – précipitation lors des périodes de fortes pluies.De plus, les eaux épikarstiques sont fortement sursaturées vis-à-vis de la calcite et leur forte minéralisation résulte de la mise à l’équilibre avec une pCO2 importante (5% en moyenne). De telles valeurs ne correspondent pas à la production de CO2 du sol. L’autre origine supposée est les épandages détritiques sablo-argileux où des teneurs importantes en CO2 ont été mesurées (pCO2air de 4 à 8%). De plus, la présence d’eau dans ces niveaux suggère que le système est en partie alimenté par ces formations. Ainsi, le transit des eaux au travers de milieux aux conditions physico-chimiques très contrastés pourrait être à l’origine de la sursaturation des eaux qui entrent dans la cavité.Enfin, l’étude montre que les épandages détritiques tiennent deux rôles majeurs dans les processus d’infiltration des eaux : (i) ils participent à leur homogénéisation en les stockant proche du sol et (ii) ils fournissent un fort potentiel de karstification au système. / It is widely recognized that the recharge of deep carbonated aquifers is controlled by a non saturated zone in which liquids, solids and gases are exchanged to attain equilibrium. The epikarstic zone, which represents the bottom of these aquifers, collects the efficient rain waters and transfers them deeper through a dual fractured and fissured porosity. Sandy-clayey detritic coatings are often observed to fossilize the paleo-relief changing the features of the infiltration zones. However, field data on these superficial deposits are sparse and their impact on the recharge modalities in karstic context is not yet well known and described.The famous prehistoric painted cave of Lascaux (France) provides a window into the epikarstic system and offers a privileged environment for the monitoring of transfer processes. The Lascaux cave is part of a fossil karstic network partly filled with detritic material and it is known to have high CO2 concentrations, greater than 8% (80,000 ppmv) in some summer periods, when measured in the air of the lower parts of the cave. Here, we study the epikarstic seepage traits monitoring the chemical and isotopic variations in waters which seep from the entrance roof of the cave. The aims of this work are to understand the dynamics of the fluids in the epikarstic system, to find the source of the high CO2 concentrations measured into the cave and to understand how the detritic coatings impact on the recharge modalities. After carried out an in-depth geological and geomorphological study of the site, the use of hydroclimatic analysis combined with the semi-monthly hydrochemical and isotopic monitoring of the epikarstic waters allowed us to investigate the karstic infiltration zone functioning in term of matter transfer. First, we observed that the epikarstic emergence is non perennial and dries up at the beginning of summer. The system needs an approximately 250 mm recharge in autumn before seeing flows at the emergence. The 18O signal at the emergence is highly amortized compared to the rain 18O signal which reveals the creation of an epikarstic water table that chemically homogenises waters. Thus, the mass transfers are slow in this system characterized by a fissured and nonkarstic behaviour type. The 13C data obtained at the epikarstic emergence seem to characterize the physicochemical conditions of the environments in which waters circulate during their transit in the system. They confirm the possible various origins of waters and reveal degassing – precipitation phenomena during rising periods.Moreover, épikarstic waters are always supersaturated with respect to the calcite and the the high bicarbonates and calcium concentrations result from water equilibrate with an important pCO2 at saturated state (5% on average). Such values of pCO2 do not correspond to the soil CO2 production. The other supposed origin is the sandy clayey detritic formations where we measured important pCO2 (data range from 4 to 8% in the atmosphere of the coatings). Furthermore, the presence of water in the sandy levels of the coatings suggests that the system can be partly fed by these formations. The transit of water through two physicochemicaly highly contrasted environments would be at the origin of the general flows supersaturation state in the cave.Finally, the study shows that the detritic coatings are involved in two aspects of the epikarstic waters run-off conditions: (i) they homogenize them while retaining near to the soil and (ii) give to them a very high karstification potential.

The aim of this thesis is to evaluate the impact of agricultural activity on hydrochemical parameters of surface waters in connection with the occurence of specially protected species within the surface waters of a monitored area. A model was chosen for the evaluation of the situation - Bedřichovský potok, which is located in Novohradské hory. The river consists of lower and upper sub-waters. Forest management is applied within upper sub-basin, while agricultural management on arable land, meadows and pastures is used in the lower sub-basin. The monitored parameters were indicators of eutrophication of surface waters: Nitrate nitrogen (N-NO3-), Phosphate phosphorus (P-PO43-), and conductivity of undissolved material (NL105). The results showed that the agriculture management (especially on arable land) burdens the soil with nutrients and consequently erosion enters the substances, bringing them to the surface and ground water as a result. There was an increase of substances in the water after rain.

Made available in DSpace on 2014-12-17T15:41:48Z (GMT). No. of bitstreams: 1 KyteriaSLF_DISSERT.pdf: 2575352 bytes, checksum: 9c601baf3a71a96816d5ae90fe0ecaea (MD5) Previous issue date: 2010-02-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Over exploitation of oil deposits on land onshore or offshore, there is simultaneous generation of waste water, known as produced water, which represents the largest waste stream in the production of crude oil. The relationship between the chemical composition of oil and water production and the conditions in which this process occurs or is favored are still poorly studied. The area chosen for the study has an important oil reserve and an important aquifer saturated with freshwater meteoric. The aim of this work is to study some chemical parameters in water produced for each reservoir zone of production in mature oil fields of A?u Formation, using the hydrochemical and statistical analysis to serve as a reference and be used as tools against the indicator ranges water producers in oil producing wells. Samples were collected from different wells in 6 different areas of production and were measured 50 parameters, which can be classified into three groups: anions, cations and physicochemical properties (considering only the parameters that generated values above detection limits in all samples). Through the characterization hydrochemistry observed an area of water and chlorinated sodium, chlorinated calcium or magnesium (mixed) in well water in different areas of A?u, by applying a statistical treatment, we obtained a discriminant function that distinguishes chemically production areas. Thus, it was possible to calculate the rate of correct classification of the function was 76.3%. To validate this model the accuracy rate was 86% / Ao longo da explora??o de petr?leo de jazidas em terra (onshore) ou no mar (offshore), existe gera??o concomitante de um efluente aquoso, denominado ?gua produzida, que representa a maior corrente de res?duo na produ??o do ?leo cru. A rela??o entre a composi??o qu?mica dos ?leos e das ?guas de produ??o, bem como as condi??es em que este processo ocorre ou ? favorecido ainda s?o pouco estudadas. A ?rea escolhida para o estudo possui uma importante reserva petrol?fera e um importante aqu?fero saturado em ?gua doce mete?rica. O objetivo desse trabalho ? estudar alguns par?metros qu?micos na ?gua produzida para cada zona-reservat?rio de produ??o em campos maduros de petr?leo da Forma??o A?u, utilizando a hidroqu?mica e a an?lise estat?stica para servir de refer?ncia e serem utilizados como ferramentas indicadoras frente a intervalos produtores de ?gua nos po?os produtores de petr?leo. Foram coletadas amostras de po?os distintos em 6 diferentes zonas de produ??o e foram medidos 50 par?metros, que podem ser classificados em tr?s grupos: ?nions, c?tions e propriedades f?sico-qu?micas (considerando-se apenas os par?metros que geraram valores acima dos limites de detec??o em todas as amostras). Atrav?s da caracteriza??o hidroqu?mica observou-se um dom?nio de ?guas cloretadas s?dicas e cloretadas c?lcicas ou magnesianas (mista) nas ?guas de po?os das diversas zonas na Forma??o A?u e, com a aplica??o de um tratamento estat?stico, obteve-se uma fun??o discriminante que distingue quimicamente as zonas de produ??o. Assim, foi poss?vel calcular a taxa de acerto de classifica??o da fun??o que foi de 76,3%. Para a valida??o desse modelo a taxa de acerto foi de 86%

Att man förstår mark- och grundvattenflöde är en förutsättning för förståelsen av ämnestransport genom skogsmark. Ståndortskarteringen har inte möjlighet att mäta grundvattenflödet på sina provytor med t ex totalpotentialmätningar utan behöver en alternativ metod. Syftet med detta arbete var att skapa en multivariat klassificeringsmodell för klassificering av grundvattenförhållandena i en skogssluttning söder om Tärnsjö i norra Uppland. Modellen bygger på principalkomponentanalys av olika kemiska variabler i det fasta organiska materialet i den organiska horisonten. De kemiska variablerna som användes var; pH(H2O), pH(BaCl2), andel C, S och N i det organiska materialet, den procentuella andelen Al3+, H+, Ca2+, Mg2+, K+ och Na+ på utbyteskomplexen, CECeff och andel organiskt material i proven. Principalkomponentanalysen tyder på att (1) inströmningsområdet karaktäriserades av lågt pH, låga Na+-halter och relativt höga K+-halter, (2) det omättade utströmningsområdet karaktäriserades av höga Al3+-halter, och (3) det näst intill mättade utströmningsområdet karaktäriserades av höga Na+-, Ca2+- och Mg2+-halter som gav högre pH-värden samt högre andel av S och N i det organiska materialet. Undersökningen tyder på att grundvattenförhållandena i en barrskogssluttning har stor betydelse för de kemiska egenskaperna hos markens organiska horisont. Informationen man får från markkemiska analyser gör det möjligt att med hjälp av kemiska variabler klassificera graden av in- respektive utströmningsförhållanden. Den multivariata klassificeringsmodell som skapades i denna undersökning ger en riktlinje för hur en generell klassificeringsmodell för indikationer av grundvattenförhållanden kan konstrueras. Den generella klassificeringsmodellen är ett alternativ till t ex totalpotentialmätningar eftersom klassificeringsmodellen varken behöver ske på plats eller mätas i tidsserier. Vidare kan klassificeringsmodellen tillämpas på redan existerande markkemiska analyser. / A thorough understanding of soil water and groundwater flow is necessary to understand the transport of elements in forest soils. The National Forest Soil and Vegetation Survey has no possibilities to determine groundwater flow using total potential measurements in the sampling plots. In the present work an alternative approach using soil chemistry to classify the extent of recharge and discharge conditions in the sampling plots was used. A multivariate model was created to classify groundwater regime in a forested hillslope south of Tärnsjö in the northern part of Uppland, Sweden. The model was based on principal component analysis (PCA) of different variables in solid organic matter in the organic horizon in the soil. The chemical variables used were pH(H2O), pH(BaCl2), total C, N and S in organic matter, the percentage of Al3+, H+, Ca2+, Mg2+, K+, Na+ in the exchange complex, the effective CEC and the percentage of organic matter in the soil samples. PCA indicated that; (1) samples from the recharge area were characterised by low pH, low Na+ and relatively high K+ levels, (2) the unsaturated discharge zone was characterised by high levels of exchangeable Al3+ and (3) the nearly saturated discharge area was characterised by high Na+, Ca2+ and Mg2+ levels, higher pH and higher amounts of N and S in the organic matter. This study indicated that groundwater regime in a forested hillslope is of major importance in determining the chemical status of the organic matter in the organic horizon. It was possible to use information obtained from soil chemical analysis to determine the extent of recharge or discharge at the points where the soil samples were taken. The PCA model used in this work gives guidelines for the construction of a general model for classification of groundwater regimes.

Variable groundwater quality in complex aquifer-aquitard systems presents a challenge for sustainable groundwater development. In the Lower Murrumbidgee alluvial fan of the Murray-Darling Basin in semi arid inland Australia, shallow groundwater is saline (12000 &micro S/cm) and locally contaminated by nitrate. Deep fresh aquifers (150 &micro S/cm), developed as an irrigation water supply, were thought to be protected from downwards leakage by laterally extensive aquitards. However, hydrochemical sampling, augmented by historic data, revealed that aquifer salinisation (400 to 4000 &micro S/cm) had occurred at some sites to 50 m depth since the mid 1980s. Aquitard windows, landscape depositional features at a scale of 10s to 100s of metres which are rarely detected by conventional investigations, were proposed as conduits for rapid downwards leakage in stressed systems. Intensive research was conducted at the Tubbo site where downhole geophysical logging and minimally disturbed cores were used to describe a saline clayey silt to 15m depth, an indurated clayey sand and 2 deep deposits of hard clayey silt. Fracturing was inferred by the scale dependency of aquitard permeability (Kv 10E-11 to 10E-6 m/s). Lithological variation near the surface was delineated by electrical imaging which revealed a 40m wide aquitard window beneath a veneer of smectite clay. Intensive monitoring of groundwater pressures in six piezometers (23-96 m depth) near the Tubbo irrigation bore and two other peizometers upgradient, indicated that the indurated clayey sand formed an effective hydraulic barrier but the deep silty deposits were spatially discontinuous. Groundwater samples were collected before, three times during, and after the 1998-99 irrigation season. A large, but delayed TDS increase occurred in the shallow aquifer and small pulses of saline water were sustained in the middle aquifer but shortlived in the deep aquifer. Hydrochemical and isotopic data dC-13, dH-2, dO-18, C-14 and H-3) showed the middle aquifer mixing with the deep aquifer, though retaining the signature of a palaeowater. Hydrochemical changes were accounted for with PHREEQC inverse mass balance models for the shallow aquifer. Mixing of aquifer water with 20-70% saline porewater from the upper aquitard occurred, together with ion exchange and NaCl dissolution. Based on an axisymmetric radial FEFLOW model, 5-30% of the volume pumped was accounted for by vertical leakage from the middle aquifer. Leakage from the shallow aquifer was small but significant, as it allowed high salinity water to migrate. Permeability and compressible storage measurements (Ss 10E-5 to 10E-4 /m) were used to constrain model calibration, and to show that direct mixing occurred mainly via aquitard windows at depth, and between the shallow and middle aquifers via leaky boreholes. Fracture flow and aquifer-aquitard interaction by diffusion were of secondary importance.

Groundwater chemistry is a function of recharge and the input chemistry of the rain, which gets transformed as it moves through the soil matrix. Apart from mineral transformations, anthropogenic activities are other external factors, which affect the groundwater chemistry. Stream – aquifer interactions alter the chemistry of groundwater in the regions nearer to the stream. A study is carried out to analyse the hydrogeochemical behavior under the influence of lithologic, precipitation and anthropogenic controls in the upper Cauvery basin. This is followed by the analysis of contributions made by the components of the hydrogeochemical cycle. A geochemical model is developed, which is used to study the spatiotemporal variations in groundwater chemistry of a silicatic rock group in a small experimental watershed. In order to study the effects of precipitation control on the groundwater chemistry the Upper Cauvery river basin (~ 10000 km2) is selected for the analysis, which stretches along three climatic zones – ‘semi-arid’ (500 – 800 mm/year rainfall), ‘sub-humid’ (1000 - 1200 mm/year) and ‘humid’ (1200 – 1500 mm/year) zones. The basin is mainly formed by granitic gneissic group of rocks with some traces of amphibolites and charnockites. Groundwater is observed to occur either in the saprolite or in the deeper hard rock zone based on the geomorphology even at the scale of a small watershed. Parts of this basin are under canal irrigation and are drained by Kabini and Cauvery Rivers. Groundwater – surface water interactions play an important role in these regions. Irrigation with different levels of intensities is practiced through groundwater in the upland areas. Observation wells considered in these three zones are classified into four classes based on the mean annual groundwater fluctuations. Wells in each of these four classes are further classified into ‘shallow’ and ‘deep’ categories based on the depth to groundwater. Analysis of the groundwater chemistry in the basin (widely spread with 120 wells in the three zones) shows a gradient in chemistry along the climatic gradient with sub-humid zone bridging between the semi-arid and humid zones. Ca/Na and Mg/Na ratios decrease from humid zone (unimodal rainfall) to semi-arid (bimodal rainfall) zone since both Na and Mg concentrations in groundwater increase along this gradient. These elements are mainly controlled by weathering reactions. Apart from the weathering of Ca, calcrete formations also play an important role in the semi-arid zone. Ion exchange process cycles between Cl and SO4 and between Ca and Na. Dissolution of CaCO3, silicate weathering and evaporation are the major mineralogical reactions. Variations in Na/Cl and Ca/Cl molar ratios indicate that shallow wells have higher molar ratios with higher variance than the deeper wells. Semi-arid zone is more silicaceous (higher Na/Cl value) than the humid zone, which has higher Ca/Cl ratio (~ 14). Effective seasonal patterns are identified using ‘recharge – discharge’ concept based on the rainfall intensity. Wells under normal scenario have low Na/Cl and Ca/Cl ratios in the ‘recharge period’ than in the corresponding ‘discharge period’ (dilution chemistry). Wells in the relatively higher pumping regions, which receive sufficient annual recharge exhibit dilution chemistry though groundwater level fluctuations are higher. However, wells in regions with insufficient recharge show ‘anti - dilution’ chemistry. Thus, the ‘recharge – discharge’ concept is useful in identifying the pumped wells from deeper wells and helps in characterizing the anthropogenic effects on the basin. Rainfall and its chemistry are to be analysed to understand the groundwater chemistry. Hence, data from various monitoring stations in India are analyzed for assessing the influence of several major factors such as, topographic location of the area, its distance from sea and annual rainfall. These stations are categorized as ‘urban’, ‘suburban’ and ‘rural’. pH, HCO3, NO3 and Mg concentrations have not changed much from coast to inland. On the other hand, SO4 and Ca concentrations changes are subjected to local emissions. Cl and Na (marine elements) originate solely from sea and a model is developed to quantify the variation in concentration of these elements under the influence of inland distance and annual rainfall. Non – linear regression model for the various categories shows that both rainfall amount and precipitation chemistry follow a power law reduction with distance from sea. Cl and Na decrease rapidly for the first 100 km distance from sea, then decrease marginally for the next 100 km and then later stabilize. Regression parameters estimated for different cases are found to be consistent (R2 ~ 0.8). Variation in one of the regression parameters accounts for the effect of urbanization. Model developed for precipitation chemistry is validated using stations from the southern peninsular region of the country. Model predictions are found to be in good correlation with observations with a relative error of ~ 5%. This relationship between the three parameters – rainfall amount, coastline distance, and concentration (in terms of Cl and Na) was validated with experiments conducted at Mule Hole SEW and Kalekere. Monthly variations in precipitation chemistry at these stations are predicted from a downscaled (in time) model and then compared with the observed data. Models developed at both annual and monthly scale are found to perform well with the field observations. Hence, this model is used for predicting the precipitation chemistry (in terms of Cl and Na) of different station points in the upper Cauvery basin. Comparative performance of alternate methods of recharge estimation i.e. Chloride mass balance (CMB) and water table fluctuation (WTF) approaches, is analyzed at various stations in the basin. Annual rainfall, Cl concentration in rain (predicted from precipitation model) and the concentration of Cl in the groundwater are the inputs for the CMB approach. Since main source of Na is from atmosphere, Na is taken as an alternative for Cl in the CMB approach and recharge is estimated using sodium mass balance (SMB) approach. Na concentrations contributed from weathering are quantified and eliminated in the analysis. Recharge estimated using SMB approach is found to be higher than CMB estimate in the semi-arid and the sub-humid zones. Water table fluctuation (WTF) method is used to compare the recharge obtained from both CMB and SMB approaches. Estimates using WTF approach are found to be higher than both CMB and SMB in the semi-arid and the sub-humid zones while SMB is found to be higher than CMB estimates. SMB and WTF estimates match well in the humid zone. An exponential relationship between recharge and annual rainfall is observed. Recharge coefficient estimated on an annual scale varied from 0.1 to 0.25 across the basin. Among CMB and SMB approaches, SMB is a better alternative for recharge estimation in semi-arid zones, where WTF approach performed poorly. Water – rock reactions are driven by the inequilibrium reactions of water with the mineral assemblage in the rock. These reactions evolve towards equilibrium with the primary minerals while a series of secondary minerals precipitate. Mass balance approach is adopted to quantify the rate at which the water – rock interactions occur in order to reach the equilibrium. Field experiments in the experimental watershed (Mule Hole SEW, ~ 4.5 km2) are carried to identify the minerals present in the region and their composition. Quartz, oligoclase, sericite, epidote and chlorite are the primary minerals while kaolinite and Fe-oxides are the secondary minerals present in this region. Percentages of oxides of different elements in each of these minerals are determined from the field experiments. Stoichiometric coefficients of different elements in each of these minerals are determined from these percentages. Long – term weathering rates are determined using these stoichiometric coefficients along with the mass fluxes of each element. Set of minerals present at different depths are found to vary among the thirteen observation wells of Mule Hole SEW. Hence, the mass balance calculations resulted in different weathering rates for a particular mineral based on the spatial location and the particular depth of the occurrence of the mineral. These weathering rates are tested for the sensitivity to carbonates with the inclusion of calcite in the mass balance calculations. With this sensitivity analysis it is observed that the presence of carbonates in the nodular form in the shallow wells has not changed the weathering reactions and their rates, and hence these wells are termed to be in the ‘silicate with secondary carbonate’ system. On the other hand, carbonates are not present in deeper wells, inclusion of which alters the equilibrium of the mass balance calculations. Thus, these wells are said to belong to the ‘silicate’ system. Anorthite present in some of the wells (MH2 and MH6) dissolves accompanied with the dissolution of carbonates. These wells are observed to belong to the third group the ‘amphibolites with primary carbonate’ system. Weathering rates of all the minerals present in these three different systems are also determined annually (short term rates). Mean of these short – term rates are observed to be the same as the long – term (over a period of 4 years) weathering rates with a minor difference of 3 – 10% in values. Thus, the weathering rates determined using mass balance approach is used to determine the quantities of concentrations of different elements contributed from the mineralogical reactions. Temporal variations in the concentrations of different chemical species in this small experimental watershed are simulated using a hydrogeochemical model. The model is developed based on a mixing cell approach, which considers the spatiotemporal variations in the recharge and the weathering inputs. Most of the weathering reactions are observed to take place in the saturated zone, which is termed as the ‘mixing zone’. This zone extends from few meters above the groundwater table to few meters below the water table. Mixing zone is discretized into series of ‘cells’ and concentrations in this zone are simulated. This group of cells is assumed to move along with the groundwater fluctuation. Sensitivity of the model is analysed subject to the variations in the recharge and the weathering fluxes. The developed model is used to simulate the concentrations of the groundwater in the three systems – ‘silicate’, ‘silicate with secondary carbonate’ and ‘amphibolites with primary carbonate’. Field data for chemical species is observed to vary in this mixing zone, boundaries of which are defined from the model simulations. Simulations corresponding to the cell at the mid depth of this mixing zone are observed to correlate well with the field data. Hence, the model developed is able to simulate the temporal variations in the groundwater chemistry. In summary, the study analyses the effects of lithological, climatic and anthropogenic factors on groundwater chemistry. The transformations in the rainwater chemistry as it reaches groundwater are analysed along different stages. A hydrogeochemical model is developed to simulate the groundwater concentrations in three different mineralogical settings over a period of three years.

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Made available in DSpace on 2014-06-11T19:26:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-09-13Bitstream added on 2014-06-13T18:54:18Z : No. of bitstreams: 1 baessa_mpm_me_rcla.pdf: 2451214 bytes, checksum: 3876fa480ca0e2bb77803a47b1630c54 (MD5) / Visando caracterizar assinaturas geoelétricas em áreas contaminadas por hidrocarbonetos de petróleo, foram realizados levantamentos geofísicos utilizando-se os métodos da eletrorresistividade e análises hidroquímicas em área localizada no Pólo Industrial de Cubatão – SP. Foram realizadas 19 sondagens elétricas verticais (SEVs), 4 imageamentos elétricos 2D e 3 imageamentos elétricos 3D, tendo sido identificadas, por meio destas técnicas, 12, 21 e 9 anomalias, respectivamente. Constatou-se que a presença de anomalias condutivas na zona não saturada coincide com a ocorrência de fase livre nos poços de monitoramento. A identificação de NH4 +, subjacente à ocorrência de fase livre, confirmou a atuação de processo de denitrificação. As baixas concentrações dos íons sulfato (SO4 2-) e ferroso (Fe2+) indicam que os mesmos foram reduzidos biologicamente para sulfeto (S2-) e precipitado como sulfeto de ferro (FeS), respectivamente. Esses resultados permitem concluir que as anomalias condutivas estão diretamente associadas à presença de fase residual de hidrocarbonetos, em processo de biodegradação, na zona não saturada. Desta forma, os métodos de investigação geofísica utilizados permitiram identificar áreas sob influência de hidrocarbonetos de petróleo. / Geophysical surveys using electroresistivity methods and hydrochemical analyses were applied aiming the characterization of geoelectrical signatures in hydrocarbon contaminated sites located in the Polo Industrial de Cubatão – SP. There have been accomplished nineteen vertical electric soundings (VESs), four 2D and three 3D electrical imaging, which identified 12, 21 and 9 geophysical anomalies respectively. It was verified that the presence of conductive anomalies within the non-saturated zone coincided with the occurrence of free phase on the monitoring wells. Ammonium (NH4 +) identification, underlying the free phase occurrence, reinforced the activity of denitrifying process. Additionally, low concentration values of sulfate (SO4 2-) and ferrous (Fe2+) ions indicated that they were, respectively, biologically reduced to sulfide (S2-) and precipitated as iron sulfide (FeS). Based on those results, it was concluded that the conductive anomalies detected inside the non-saturated zone were directly associated with the presence of hydrocarbon residual phase, with was undergoing a biodegradation process. Therefore, the geophysical methods applied in this study allowed the identification of sites under petroleum hydrocarbons influence.

Made available in DSpace on 2014-12-17T15:19:59Z (GMT). No. of bitstreams: 1 JailsaSM.pdf: 722262 bytes, checksum: b5daa60e103a373c84c164786328442f (MD5) Previous issue date: 2006-05-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The fissures aquifer northeast semi-arid Brazilian, present high text frequently of leave, with of low a h?dric availability. The research has as objective main to analyze the components that inside influence in the salinity of the waterbearing fissures of an evaluation physicist-chemistry of the water, leading in consideration the physical interventions of the environment. One used techniques of interpretation of image of Landsat satellite -1999 and delimitation of the micro basin through the topographical map SUDENE. One identified waters of the NaCl type with Ca++ and Mg++ in secondary concentrations. The analyzed wells (15), had presented an average salinity of 5.147 mg/L of STD and a well only supplies drinking waters with 319 mg/L of STD. The recharge of the aquifer one if carries through for infiltration in the open fracture of ortognaisse it migmatization. The type and directions of the fracture do not control the STD. Relations between salinity and out let do not exist. The quality of the well of low salinity is identical the superficial waters (aquifer dam and alluvial). The studies of the meteoric erosion processes had evidenced that in the transformations of the rock in ground, the Ca++ and Na+ are taken for superficial waters. The treatment of the data chemical showed that the grade of Na+, Ca++, Mg++ and Cl-are controlled for the evaporation process, from only water that would have the qualities of superficial waters or the well of low salinity. Already the HCO3-grade is controlled for the precipitation of the dolomite. The STD of this aquifer one would be consequence of the high tax of evaporation of dams constructed in regions of plain topography. You leave them precipitated in deep argillaceous ones dry dams are led for the aquifer in first rains. The research suggests some recommendations for the use and exploitation of the water salinity in piscicultura, carcinicultura, culture of the grass-salt (Atriplex sp), among others / Os aq??feros fissurais do Nordeste semi-?rido Brasileiro, apresentam freq?entemente elevado teor de sais, al?m de uma baixa disponibilidade h?drica. A pesquisa tem como objetivo principal analisar os componentes que influenciam na salinidade dos aq??feros fissurais dentro de uma avalia??o f?sico-qu?mico da ?gua, levando em considera??o as interven??es f?sicas do ambiente. Utilizou-se t?cnicas de interpreta??o de imagem de sat?lite Landsat -1999 e delimita??o da microbacia atrav?s da carta topogr?fica de Lajes SUDENE. Identificou-se ?guas do tipo NaCl com Ca++ e Mg++ em concentra??es secund?rias. Os po?os analisados (15), apresentaram uma salinidade m?dia de 5.062 mg/L de STD e somente um po?o fornece ?gua pot?vel com 319 mg/L de STD. A recarga do aq??fero se realiza pela infiltra??o nas fraturas abertas do ortognaisse migmatizado. O tipo e dire??es das fraturas n?o controlam a concentra??o de STD. N?o existe rela??o entre STD e vaz?o. A qualidade do po?o de baixa salinidade ? id?ntica as ?guas superficiais (a?ude e aq??fero aluvionar). Os estudos dos processos de intemperismo evidenciaram que nas transforma??es da rocha em solo, o Ca++ e Na+ s?o levados para as ?guas superficiais. O tratamento dos dados qu?mico mostrou que os teores de Na+, Ca++, Mg++ e Cl-s?o controlados pelo processo de evapora??o, a partir de uma ?gua ?nica que teria as qualidades das ?guas superficiais ou do po?o de baixa salinidade. J? os teores de HCO3 s?o controlados pela precipita??o da dolomita. A salinidade deste aq??fero seria conseq??ncia da alta taxa de evapora??o dos a?udes constru?dos em regi?es de topografia plana. Os sais precipitados nos fundos argilosos dos a?udes secos s?o levados para o aq??fero nas primeiras chuvas. A pesquisa sugere algumas recomenda??es para a utiliza??o e aproveitamento da ?gua salinizada em piscicultura, carcinicultura, cultivo da erva-sal (Atriplex sp), entre outras

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A Ãrea deste estudo de hidrogeologia abrange a Bacia do BanabuiÃ, trecho entre Quixeramobim e BanabuiÃ, e està localizada Ãs margens dos rios Quixeramobim e BanabuiÃ. à necessÃrio para os usuÃrios e gestores conhecer os aspectos qualitativos e quantitativos das Ãguas usadas e a interaÃÃo entre as Ãguas dos rios Quixeramobim e Banabuià com os aquÃferos aluvionares. O objetivo deste estudo foi aprofundar os conhecimentos sobre a hidrogeologia dos aluviÃes em relaÃÃo Ãs reservas, qualidade e hidrodinÃmica das Ãguas. Para isto, realizou-se o cadastro de poÃos, monitoramento das variaÃÃes dos nÃveis estÃticos, levantamento planialtimÃtrico, levantamento geofÃsico por resistividade, medidas de parÃmetros fÃsico-quÃmicos, biolÃgicos, metais pesados, anÃlises isotÃpicas (18O e D) nas Ãguas da chuva, dos poÃos, dos rios Banabuià e Quixeramobim, e do aÃude BanabuiÃ. A estimativa das reservas dos aquÃferos aluvionares tambÃm foi realizada. No tratamento e interpretaÃÃo dos dados usou-se o diagrama de Piper, diagrama USSL, Ato e Resist, para interpretaÃÃo das SEVs, programa Surfer 8.0 para simulaÃÃo do fluxo subterrÃneo, e padrÃes de potabilidade da portaria N 2914/2011 do MinistÃrio da SaÃde. Verificou-se que o fluxo subterrÃneo dirige-se na mesma direÃÃo dos rios Quixeramobim e BanabuiÃ, ou seja, em direÃÃo ao Leste. O aquÃfero aluvionar apresenta uma espessura mÃdia da ordem de 7,08 m. A recarga dos aluviÃes no trecho entre Quixeramobim e Banabuià foi de 6,09x106 m3/ano e a reserva permanente à de aproximadamente 34,8x106 m3. Os principais problemas para o consumo humano das Ãguas (superficiais e subterrÃneas) sÃo os coliformes totais, o elemento ferro, a elevada salinidade, o nitrato, o manganÃs e o alumÃnio, estes se encontram com valores acima do permitido pela Portaria n 2914 do MinistÃrio da SaÃde. Portanto, estas Ãguas sà podem ser consumidas apÃs o devido tratamento. Para o uso na irrigaÃÃo, as Ãguas superficiais e dos aluviÃes podem ser utilizadas sem muitos problemas, jà a Ãgua do domÃnio hidrogeolÃgico cristalino, requer uma prÃtica de irrigaÃÃo controlada. A reta meteÃrica local dos isÃtopos estÃveis para o perÃodo estudado foi muito semelhante à GMWL. Os aquÃferos aluvionares recebem alimentaÃÃo pelos rios Quixeramobim e BanabuiÃ. As Ãguas dos poÃos do domÃnio hidrogeolÃgico cristalino sofreram recarga apenas por Ãguas meteÃricas. As Ãguas dos poÃos do aquÃfero aluvionar sugerem que sofreram evaporaÃÃo durante a recarga. Finalmente, ocorre uma estratificaÃÃo (tÃrmica e quÃmica) no perÃodo chuvoso e uma desestratificaÃÃo no perÃodo de estiagem. / The area of this hydrogeological study covers the Banabuià Basin, in the stretch between Quixeramobim and BanabuiÃ, and is located on the banks of rivers Quixeramobim and BanabuiÃ. It is necessary for users and water managers to be aware of the qualitative and quantitative aspects of the water and the interaction between the rivers Quixeramobim and Banabuià and the alluvial aquifers. For these reasons, we sought to deepen the knowledge about the hydrogeology of the alluvial deposits with respect to reserves, hydrodynamics and water quality. Methods included a data bank of wells, monitoring of changes in static levels, a planialtimetric survey, a geophysical survey by electric resistivity, measurements of physico-chemical and biological parameters, heavy metals, stable isotope analyses (18O and D) in rain, waters from wells, rivers Banabuià and Quixeramobim, and Banabuià dam. An estimation of reserves of alluvial aquifers was also made. In the treatment and interpretation of the data Piper and USSL diagrams were used as well as, Ato and Resist for interpretation of VES, program Surfer 8.0 for simulation of groundwater flow; potability standards of Portaria NÂ. 2914/2011 of the Ministry of Health were used to judge water quality. Results indicate that the groundwater flow has in the same direction of rivers Quixeramobim and BanabuiÃ, ie eastward. The alluvial aquifer has an average thickness of approximately 7.1 m. The recharge to the alluvium in the stretch between Quixeramobim and Banabuià was of 6.09 x106 m3/year and permanent reserve is of approximately 34.8 x106 m3. The main problems for human consumption of the waters (surface and groundwater) are total coliforms, the element iron, high salinity, nitrate, manganese and aluminum; these present values higher than permitted by Portaria N 2914. Therefore, these waters can only be consumed after proper treatment. In irrigation, surface water and alluvium can be used without many problems; however, waters from the crystalline domain require a practice of controlled irrigation. The stable isotope local meteoric water line for the period studied showed a slope very similar to the GMWL. The alluvial aquifers receive recharge from rivers Quixeramobim and BanabuiÃ. Wells in the crystalline bedrock receive recharge by rainwater. The waters of the alluvial aquifer wells suggest that they suffered evaporation while recharging. Finally, there is a slight stratification in Banabuià dam (thermal and chemical) in the rainy season that disappears in the dry season.