scholarly journals Exchange between a river and groundwater, assessed with hydrochemical data

2010 ◽  
Vol 7 (6) ◽  
pp. 9023-9042 ◽  
Author(s):  
E. Hoehn ◽  
A. Scholtis

Abstract. We describe the chemical composition of groundwater from an alluvial granular aquifer in a valley fill flood plain (River Thur Valley). The aim of this work is to investigate the chemical processes, which are necessary to manage groundwater quality during river restorations. The river flows along this valley and is mostly downwelling on its way, indirectly through an unsaturated zone in the upstream part, and directly through the water-saturated bed in the downstream part. River Thur has been channelized with barriers for more than a century. Since 1992, the authorities started to restore sections of River Thur with river-bed enlargements. Several wells near the river draw groundwater, which is partly to mainly recharged by bank filtration. Many alpine and perialpine rivers have a total mineralization in the order of 200–400 mg L−1 and the chemical composition of the main constituents is of a Ca-Mg-HCO3-(NO3) type. The groundwater composition changes with increasing distance from the downwelling river and with increasing depth in the aquifer. The groundwater body consists of a mixture of groundwater from the seepage of precipitation and from river-bank filtration. The main difference between river water and groundwater results from the microbial activity in river-bed and bank materials. This activity leads to a consumption of O2 and to a higher partial pressure in CO2 in the groundwater. A spatial distribution of different groundwater types was established with geochemical mapping of concentration data, and with fluid logging. Criteria for the distinction of different groundwater compositions are the distance of a well from the river and the subsurface residence time of the groundwater to reach this well. Some of the groundwater has a very short residence time in the subsurface of days to weeks, and some of months to years. Groundwater in the River Thur valley aquifer is not pristine. The land use in the flood plain and the seasonal and climatic conditions (e.g., hot dry summer 2003) result in alterations of the natural geochemical groundwater composition. Time-series measurements of nitrate (from agricultural impact in the catchment) and chloride showed temporal changes in groundwater composition. Bed enlargements in river corridors can lead to a reduction of groundwater residence times and to an increase of riverbank filtration in nearby wells, which increases their contamination risk.

2011 ◽  
Vol 15 (3) ◽  
pp. 983-988 ◽  
Author(s):  
E. Hoehn ◽  
A. Scholtis

Abstract. We describe the chemical composition of groundwater from an alluvial granular aquifer in a valley fill flood plain (River Thur Valley). The river flows along this valley and is mostly downwelling on its way, indirectly through an unsaturated zone in the upstream part, and directly through the water-saturated bed in the downstream part. River Thur has been channelized with barriers for more than a century. In 1992, the authorities started to restore a section of River Thur with riverbed enlargements. The land use in the flood plain and the seasonal and climatic conditions (e.g., hot dry summer 2003) result in alterations of the natural geochemical composition of the river water. This groundwater is partly to mainly recharged by bank filtration. Several wells exist near the river that draw groundwater for drinking. In some of these wells, the groundwater has a very short residence time in the subsurface of days to weeks. Bed enlargements and other operations for an enhancement of the exchange of water between the river and groundwater increase the contamination risk of the nearby wells. During bank filtration, the groundwater changes gradually its composition, with increasing distance from the river and with depth in the aquifer. From today's changes of the water quality during riverbank filtration, we tried to extrapolate to the groundwater quality that may arise from future river restorations. Today the groundwater body consists of a mixture of groundwater from the seepage of precipitation and from riverbank filtration. The main difference between river water and groundwater results from the microbial activity in riverbed and bank materials. This activity leads to a consumption of O2 and to a higher partial pressure of CO2 in the groundwater. Criteria for the distinction of different groundwater compositions are the distance of a well from the river and the subsurface residence time of the groundwater to reach this well.


2015 ◽  
Vol 2 (1) ◽  
pp. 109-115
Author(s):  
Md Mahmodul Hasan Sohel ◽  
Md Ruhul Amin

The buffaloes are reared by many races under diverse agro-climatic conditions of Bangladesh. The buffaloes of Bangladesh are mostly indigenous in origin. Both the swamp and river type buffaloes are found in Bangladesh and they can be found throughout the country. However, their concentration is higher in coastal part, Meghna-Ganga and Jamuna-Brahamaputra flood plain, subsequently forming buffalo pockets. This study was conducted to identify the types of buffaloes and the sources of breeding buffaloes in one of those buffalo pockets called Kanihari buffalo pocket situated in Mymenshing district. Direct interviewing method was used to collect the data from the owner of the buffaloes. According to the body shape, coat color and horn pattern, buffaloes of this region were categorized into different categories. Abundant natural green grasses in the river bank of old Brahammaputra gave this area as a shape of a buffalo pocket. This pocket does not have any distinct breed and the buffalo population is mostly mixed and exotic. Introduction of swamp germplasm occurred when buffalo cows are temporarily migrated to Bathan area of Sylhet. Morphometric characteristics (coat color, horn pattern and body appearance) of Type-1, Type-2 and Type-3 buffaloes are similar to Murrah group (Murrah and Nili- Ravi), Surti group and indigenous river type buffaloes, respectively. This is the first study which identifies and morphologically characterizes the buffalo population in Kanihari buffalo pocket; however, in depth genotypic study is required in order to identify the origin or breeds available in this area.Res. Agric., Livest. Fish.2(1): 109-115, April 2015


Geologos ◽  
2017 ◽  
Vol 23 (3) ◽  
pp. 201-214 ◽  
Author(s):  
Jan Przybyłek ◽  
Krzysztof Dragon ◽  
Piotr Michał Jan Kaczmarek

AbstractRiver bank filtration (RBF) is a system that enriches groundwater resources by induced infiltration of river water to an aquifer. Problematic during operation of RBF systems is the deterioration of infiltration effectiveness caused by river bed clogging. This situation was observed in the Krajkowo well field which supplies fresh water to the city of Poznań (Poland) during and after the long hydrological drought between the years 1989 and 1992. The present note discusses results of specific hydrogeological research which included drilling of a net of boreholes to a depth of 10 m below river bottom (for sediment sampling as well as for hydrogeological measurements), analyses of grain size distribution and relative density studies. The results obtained have allowed the recognition of the origin of the clogging processes, as well as the documentation of the clogged parts of the river bottom designated for unclogging activities.


2018 ◽  
Vol 15 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Medalson Ronghang ◽  
Pranjal Barman ◽  
Hemantajeet Medhi ◽  
Kamal Kumar Brahma ◽  
Arup Kumar Misra

Abstract River bank filtration (RBF) is a natural method of obtaining surface water from a river or lake via the sub-surface for domestic use. It has been intensively used worldwide to augment water supply systems for sustainability and can be operated under various conditions. Its energy requirements are comparatively lower than those of conventional water treatment systems. Field investigations were carried out at various locations in Kokrajhar district of Assam, India to assess groundwater quality and aquifer characteristics. The results suggest that major water quality parameters were within the Indian drinking water standards. The iron concentration exceeded the permissible maximum in more than 50% of samples from hand pumps, its concentration ranging between 0.33 and 3.50 mg/L. The pH was mostly in the range 5.4 to 7.4, suggesting that the water is slightly acidic. Aquifer and riverbed material collected along the banks of the Gaurang River were sieved, and classified as coarse silt to fine gravel, with gravel and sand predominant. The hydraulic conductivity, determined from the grain size distributions, were between 5 × 10−3 and 1.4 × 10−2 m/s, suggesting good aquifer permeability. The maximum safe well yield was estimated at 2,000 to 7,500 L/min, and the mean travel time at less than a week during the monsoon and more than 3 years under non-monsoon conditions. The aim of this paper is to demonstrate the RBF method for treating river water naturally under wet climatic conditions. The lower Brahmaputra basin is a unique physiographic setting with a powerful monsoon regime and a fragile geological base. The approach was to prepare a comparative study of water quality and aquifer characteristics with the present site and few active RBF sites.


2021 ◽  
Author(s):  
Miguel Angel Marazuela ◽  
Paulo Herrera ◽  
Klaus Erlmeier ◽  
Robert Brünjes ◽  
Philip Brunner ◽  
...  

<p>Many drinking water systems worldwide are based on river bank filtration. From a quantitative point of view river bank filtration systems are highly reliable because of the high permeability of alluvial aquifers linked to high production rates. However, there might be an increased risk of contamination because of the short residence time between the river and the production well, especially during flood events.</p><p>Flood events change the river-aquifer hydraulic interactions and may increase infiltration rates (e.g., due to an increased hydraulic head, larger river infiltration widths, or erosion of a siltation layer). This leads to changes in groundwater flow paths and production wells might abstract water with a shorter residence time and lower quality. Groundwater quality may degrade during flood events due to the presence of undesirable chemicals (e.g., wastes water treatment plant overflow) and the occurrence of faecal indicator bacteria such as <em>E.Coli</em>.</p><p>Groundwater modelling can assist in developing strategies to protect river bank filtration from such undesired contamination by predicting optimal operation conditions. The key impediment of this approach is significant uncertainties in subsurface properties and the associated uncertainties of the groundwater flow paths. To reduce uncertainties in model predictions, anthropogenic tracers including the MRI contrast agent gadolinium and artificial sweeteners were used in this study. They revealed sources and flow patterns, and have been used to derive mixing ratios representing different temporal and spatial scales. Including anthropogenic tracers into the objective function of the calibration process also lead to more accurate estimation of groundwater flow paths. This was critical to predict the best water works operation strategy during flood events.</p>


2018 ◽  
Vol 12 (2) ◽  
pp. 1-7
Author(s):  
Sînziana Venera Morărița

Abstract Although relatively recent, peach culture has grown great in our country due to the special quality of the fruit, its very complex chemical composition and the large production that can be obtained without much effort. Peach is a species slightly adapted to our climatic conditions, suffers from winter frost, but can provide productive and long productions of 10-15 years.


1988 ◽  
Vol 30 (3) ◽  
pp. 315-330 ◽  
Author(s):  
Julie M. Palais ◽  
Philip R. Kyle

The chemical composition of ice containing tephra (volcanic ash) layers in 22 sections of the Byrd Station ice core was examined to determine if the volcanic eruptions affected the chemical composition of the atmosphere and precipitation in the vicinity of Byrd Station. The liquid conductivity, acidity, sulfate, nitrate, aluminum, and sodium concentrations of ice samples deposited before, during, and after the deposition of the tephra layers were analyzed. Ice samples that contain tephra layers have, on average, about two times more sulfate and three to four times more aluminum than nonvolcanic ice samples. The acidity of ice samples associated with tephra layers is lowered by hydrolysis of silicate glass and minerals. Average nitrate, sodium, and conductivity are the same in all samples. Because much of the sulfur and chlorine originally associated with these eruptions may have been scavenged by ash particles, the atmospheric residence time of these volatiles would have been minimized. Therefore the eruptions probably had only a small effect on the composition of the Antarctic atmosphere and a negligible effect on local or global climate.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2949
Author(s):  
Juan I. Burneo ◽  
Ángel Benítez ◽  
James Calva ◽  
Pablo Velastegui ◽  
Vladimir Morocho

Chemical compositions of plants are affected by the initial nutrient contents in the soil and climatic conditions; thus, we analyzed for the first time the effects of soil and leaf nutrients on the compositions of the essential oils (EOs) of Siparuna muricata in four different localities in Ecuador. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and a gas chromatography/flame ionization detector (GC/FID). Enantiomeric distribution by GC/MS was determined, modifying the enantiomeric separation of β-pinene, limonene, δ-elemene, β-bourbonene, cis-cadina-1 (6), 4-diene and atractylone. A total of 44 compounds were identified. The most representative for L1 were guaiol, atractylone and 4-diene; for L2, cis-cadina-1(6),4-diene and myrcene; for L3, atractylone, myrcene and germacrene B; and finally, L4 germacrene B, myrcene and cis-cadina-1(6),4-diene. Correlations between soil- leaf chemical elements such as Al, Ca, Fe, Mg, Mn, N and Si in the different localities were significant with chemical composition of the essential oil of Siparuna muricata; however, correlations between soil and leaf K, P, and Na were not significant. Cluster and NMDS analysis showed high dissimilarity values of secondary metabolites between four localities related with changes in soil- leaf nutrients. Thus, the SIMPER routine revealed that not all secondary metabolites contribute equally to establishing the differences in the four localities, and the largest contributions are due to differences in guaiol, cis-cadina-1(6),4-diene, atractylone and germacrene. Our investigation showed for the first time the influences of altitude and soil- leaf chemical elements in the chemical composition of the EOs of S. muricata.


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