Assessment of temporal and spatial variation in chemical composition of groundwater in an unconfined esker aquifer in the cold temperate climate of Northern Finland

Okkonen, Jarkko; Kløve, Bjørn

doi:10.1016/j.coldregions.2011.10.003

Cited by 17 publications

(8 citation statements)

References 14 publications

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“…The Pudasjärvi site is located approximately 100 km northeast of the city of Oulu. The aquifer (Table ) is part of the Yli‐Ii‐Hossa interlobate complex, a glaciofluvial formation deposited between two ice lobes during the ice retreat, and is a typical small‐scale unconfined esker aquifer used for water supply in Finland (PSV‐ Maa ja Vesi ; Okkonen and Klöve ; Okkonen and Klöve ).…”

Section: Resultsmentioning

confidence: 99%

Seismic reflection surveys in glaciofluvial deposits in Finland

Okkonen

Moisio

2015

Near Surface Geophysics

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Shallow seismic reflection surveys were conducted at five different locations in central Finland during the period of 2008–2011 in order to test the applicability of this method and different seismic energy sources in providing accurate images of the underlying seismic structure and geology in unconfined and confined esker aquifers. The depth of the aquifers varied from 15 m to 140 m. Reflections from the water table and the bedrock were generally detected. In the deepest aquifers, several features of the inner structure were visible. In the shallowest aquifer (15 m thick), seismic detection of the stratigraphic units proved difficult. Analysis of the theoretical travel times and the shallow structure suggested that a higher frequency seismic source might have been needed. In the deeper aquifers, reflections near the bedrock were detected, but information regarding their thicknesses could not be obtained. An unsaturated layer with a thickness of 25 m did not completely attenuate the seismic signal, and reflections from the water table and bedrock (~80 m) could still be obtained. For the amount of explosives and the type of vibrator used in this study, explosives generally produced clearer reflections due to the higher signal‐to‐noise ratio compared with the vibrator source. On the other hand, shot‐to‐shot fluctuations in signal‐to‐noise ratio and source irreproducibility were found to be greater for explosives than for the vibrators. Loose lake sediments above the aquifer inhibited seismic energy transmission to the bedrock. In such situations, the use of explosives is recommended in order to obtain clearer reflections from the subsurface soil boundaries.

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Section: Resultsmentioning

confidence: 99%

Seismic reflection surveys in glaciofluvial deposits in Finland

Okkonen

Moisio

2015

Near Surface Geophysics

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“…Snowmelt in spring replenishes both surface water and groundwater, and has a major effect on the hydrological cycle in cold environments. In addition, recent studies have shown that warm weather events during winter may increase soil water content and infiltration capacity (Sutinen et al ., ), and affect groundwater quantity and quality (Okkonen & Kløve, ).…”

Section: Introductionmentioning

confidence: 99%

Multi‐year simulation and model calibration of soil moisture and temperature profiles in till soil

Okkonen

Ala‐aho

Hänninen

et al. 2017

European J Soil Science

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Summary In Nordic regions water infiltration into soil is controlled by soil moisture content and frozen soil conditions, which are regulated by soil temperature. For long‐term model predictions of the effects of climate change, models need to be tested with long‐term data to assess model sensitivity to parameter uncertainties under both typical and exceptional conditions. Ten‐year (2002–2011) daily soil moisture and temperature data at different depths in glacial till soils in central Finland were used to assess the sensitivity of a coupled heat and water transfer model, COUP, to model parameters. The model was most sensitive to the parameters controlling snow accumulation and melt, the thermal conductivity of frozen soil and soil water retention characteristics. Observed time series for soil temperature and moisture at different depths were matched reasonably well by model simulations, although the model performance with respect to moisture dynamics in the topsoil was relatively poor. The model was not able to simulate accurately exceptional winter conditions, such as mid‐winter snowmelt events. This study showed that the main characteristics of long‐term variation in soil temperature for till‐derived soil in a cold climate can be resolved by a coupled water and heat transport model. Better characterization of infiltration in cold climates would require measurement of water fluxes, and soil frost occurrence and penetration. Highlights Ten‐year soil temperature and moisture observations are predicted with coupled heat and water model. Snow processes and soil thermal and water retention properties proved critical in our simulations. Exceptional winter conditions pose a challenge in parameterization of the model. Studies measuring water fluxes and soil frost occurrence are needed for advances in modelling.

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“…According to many authors (Hem 1985, Bricker andJones 1995), water chemical composition is controlled by many factors, which include composition of precipitation (Dzhamalov and Zlobina 1995), mineralogy of river basins (Oyarzûn et al 2013), aquifers (Kortelainen and Karhu 2009), climate (Okkonen and Kløve 2012) and topography (Ielpo et al 2012). Those factors may combine to create various types of water with a change in composition over space and time (Yidana 2008).…”

Section: Introductionmentioning

confidence: 99%

Spatial and temporal variability of groundwater quality of an Algerian aquifer: the case of Soummam Wadi

Benhamiche

Sahi

Tahar

et al. 2016

Hydrological Sciences Journal

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Five-year monitoring of physicochemical parameters was performed with two campaigns in low and high water periods of the Lower Soummam catchment. Data from 18 wells were processed by multivariate statistical tools in order to identify the principal factors influencing groundwater chemistry. Two matrices of 14 and 8 physicochemical parameters with 18 groundwater samples collected in wells were obtained. The correlation matrix showed strong associations between nine variables: K + , Ca 2+ , Na + , SO 4 2− , Cl − , Mg 2+ , NO 2 − , Zn 2+ and Sr 2+. Principal component analysis and factor analysis showed that the cumulated variance of high and low water periods was of 83.19% and 78.55%, respectively. The variables assigned to the mineralization effect or to pollution indicators were presented by the factor analysis. The bivariate plots confirmed a mineralization model, ascribed to dissolution of geological materials, and to high levels of saline contamination attributed to leakages from sanitary systems. They also showed an increase "upstream to downstream" of the mineralization, visualization of temporal variations, and a dilution process identification of the natural mineralization during the recharge of the aquifer.

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Assessment of temporal and spatial variation in chemical composition of groundwater in an unconfined esker aquifer in the cold temperate climate of Northern Finland

Cited by 17 publications

References 14 publications

Seismic reflection surveys in glaciofluvial deposits in Finland

Seismic reflection surveys in glaciofluvial deposits in Finland

Multi‐year simulation and model calibration of soil moisture and temperature profiles in till soil

Spatial and temporal variability of groundwater quality of an Algerian aquifer: the case of Soummam Wadi

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