scholarly journals A physical study of the effect of groundwater salinity on the compressibility of the Semarang-Demak aquitard, Java Island

2018 ◽  
Author(s):  
Dwi Sarah ◽  
Lambok M. Hutasoit ◽  
Robert Delinom ◽  
A. Sadisun
Keyword(s):  
Coastal Region ◽  
Clay Mineralogy ◽  
Physical Analysis ◽  
Groundwater Salinity ◽  
Saline Groundwater ◽  
Fabric Analysis ◽  
Physical Study ◽  
Consolidation Rate ◽  
Compression Characteristics

This article is currently under review oin Journal of Geosciences, MDPI. Authors: Dwi Sarah, Lambok Hutasoit, Robert Delinom, Imam A. Sadisun, Taufiq Wirabuana -- Semarang-Demak and other cities along the coast of North Java are vulnerable to land subsidence. The presence of saline groundwater in the coastal region is thought to affect the high subsidence rate, in this case the compressibility of the aquitard layer. We aimed to analyze the effects of groundwater salinity on the compression characteristics of the Semarang-Demak clay using physical analysis. Methods included the determination of groundwater salinity, clay mineralogy and fabrics, and consolidation tests under various salinity conditions. The Semarang-Demak clay is dominated by smectite of high activity and saline clay exists at the depth of 10 to 35 m. Consolidation tests reveals that the increase of salinity increases the average consolidation rate and hydraulic conductivity up to 42% and 37.5%, respectively. Clay fabric analysis showed that the groundwater salinity modified the interconnectivity of pores by changing the fabric into parallel alignments, facilitating faster porewater dissipation, hence the clay is more readily compressed. These findings are useful for explaining the mechanism of the fast-subsiding coastal plains of North Java.

scholarly journals Groundwater salinity variation in Upazila Assasuni (southwestern Bangladesh), as steered by surface clay layer thickness, relative elevation and present-day land use

2019 ◽  
Vol 23 (3) ◽  
pp. 1431-1451 ◽  
Author(s):  
Floris Loys Naus ◽  
Paul Schot ◽  
Koos Groen ◽  
Kazi Matin Ahmed ◽  
Jasper Griffioen
Keyword(s):  
Land Use ◽  
Drinking Water ◽  
Coastal Region ◽  
Shallow Depth ◽  
Hydrological Processes ◽  
Groundwater Salinity ◽  
Clay Layer ◽  
Fresh Groundwater ◽  
Salinity Variation ◽  
Clay Layers

Abstract. In the southwestern coastal region of Bangladesh, options for drinking water are limited by groundwater salinity. To protect and improve the drinking water supply, the large variation in groundwater salinity needs to be better understood. This study identifies the palaeo and present-day hydrological processes and their geographical or geological controls that determine variation in groundwater salinity in Upazila Assasuni in southwestern Bangladesh. Our approach involved three steps: a geological reconstruction, based on the literature; fieldwork to collect high-density hydrological and lithological data; and data processing to link the collected data to the geological reconstruction in order to infer the evolution of the groundwater salinity in the study area. Groundwater freshening and salinization patterns were deduced using PHREEQC cation exchange simulations and isotope data were used to derive relevant hydrological processes and water sources. We found that the factor steering the relative importance of palaeo and present-day hydrogeological conditions was the thickness of the Holocene surface clay layer. The groundwater in aquifers under thick surface clay layers is controlled by the palaeohydrological conditions prevailing when the aquifers were buried. The groundwater in aquifers under thin surface clay layers is affected by present-day processes, which vary depending on present-day surface elevation. Slightly higher-lying areas are recharged by rain and rainfed ponds and therefore have fresh groundwater at shallow depth. In contrast, the lower-lying areas with a thin surface clay layer have brackish–saline groundwater at shallow depth because of flooding by marine-influenced water, subsequent infiltration and salinization. Recently, aquaculture ponds in areas with a thin surface clay layer have increased the salinity in the underlying shallow aquifers. We hypothesize that to understand and predict shallow groundwater salinity variation in southwestern Bangladesh, the relative elevation and land use can be used as a first estimate in areas with a thin surface clay layer, while knowledge of palaeohydrogeological conditions is needed in areas with a thick surface clay layer.

scholarly journals Groundwater salinity variation in Upazila Assasuni (southwestern Bangladesh), as steered by surface clay layer thickness, relative elevation and present-day land use

2018 ◽  
Author(s):  
Floris Loys Naus ◽  
Paul Schot ◽  
Koos Groen ◽  
Kazi Matin Ahmed ◽  
Jasper Griffioen
Keyword(s):  
Land Use ◽  
Drinking Water ◽  
Coastal Region ◽  
Shallow Depth ◽  
Hydrological Processes ◽  
Groundwater Salinity ◽  
Clay Layer ◽  
Fresh Groundwater ◽  
Salinity Variation ◽  
Clay Layers

Abstract. In the southwestern coastal region of Bangladesh, options for drinking water are limited by groundwater salinity. To protect and improve the drinking water supply, the large variation in groundwater salinity needs to be better understood. This study identifies the palaeo and present-day hydrological processes and their geographical or geological controls that determine variation in groundwater salinity in Upazila Assasuni in southwestern Bangladesh. Our approach involved three steps: a geological reconstruction, based on the literature; fieldwork to collect high density hydrological and lithological data; and data processing to link the collected data to the geological reconstruction in order to infer the evolution of the groundwater salinity in the study area. Groundwater freshening and salinization patterns were deduced using PHREEQC cation exchange simulations and isotope data was used to derive relevant hydrological processes and water sources. We found that the factor steering the relative importance of palaeo and present-day hydrogeological conditions was the thickness of the Holocene surface clay layer. The groundwater in aquifers under thick surface clay layers is controlled by the palaeohydrological conditions prevailing when the aquifers were buried. The groundwater in aquifers under thin surface clay layers is affected by present-day processes, which vary depending on present-day surface elevation. Slightly higher-lying areas are recharged by rain and rainfed ponds and therefore have fresh groundwater at shallow depth. In contrast, the lower-lying areas with a thin surface clay layer have brackish–saline groundwater at shallow depth because of flooding by marine-influenced water, subsequent infiltration and salinization. Recently, aquaculture ponds in areas with a thin surface clay layer have increased the salinity in the underlying shallow aquifers. We hypothesize that to understand and predict shallow groundwater salinity variation in southwestern Bangladesh, the relative elevation and land use can be used as a first estimate in areas with a thin surface clay layer, while knowledge of palaeohydrogeological conditions is needed in areas with a thick surface clay layer.

MINERALOGICAL VARIABILITY OF THE CLAY IN A MAP DELINEATION OF BRANDON SOIL

1987 ◽  
Vol 67 (1) ◽  
pp. 83-93 ◽  
Author(s):  
G. J. ROSS ◽  
C. WANG ◽  
R. G. HILL
Keyword(s):  
Chemical Properties ◽  
Clay Mineralogy ◽  
Confidence Limits ◽  
Marine Clay ◽  
Mineral Contents ◽  
The Past ◽  
Coefficients Of Variation ◽  
Ap Horizon ◽  
Primary Mineral

The mineralogical variability of the clays from the Ap and BCg horizons of 20 pedons in a delineation of Brandon soil near Ottawa was measured. The soil has level topography, is dominantly poorly drained, and has developed from marine clay during the past 8000 yr. Smectite, vermiculite and mica were the dominant clay minerals, whereas quartz, feldspars and amphiboles were generally present in smaller amounts. The coefficients of variation (CV) among pedons were generally less than 20% indicating that the lateral distribution of minerals in the clay was relatively uniform. This was supported by the low variability (CV of 10% or less) of the chemical properties of the clay, such as cation exchange capacities and K contents, which are generally related to clay mineralogy. There were more significant differences in clay mineralogy between Ap and BCg horizons. Differences appear to have resulted from pedogenic weathering. The clay from the Ap horizon contained a higher proportion of smectite and lower proportions of mica, albite and amphiboles. Presumably, some mica had expanded to form smectite and some primary mineral grains had weathered. Decreased total amounts of Na, K and Ca in the Ap clay also reflected this weathering. The lateral uniformity of the clay mineralogy was accounted for by the relatively uniform soil forming factors and processes in this map unit. The confidence limits for variations from means of mineral contents in replicated clays as well as other results indicate that the determination of spatial variability of clay mineralogy is limited by the precision of analytical methods for mineral quantification. Key words: Mineralogical variability, map delineation, Brandon soil

Study on Indirect Method for Determination of Compression Characteristics of SMA

2000 ◽  
Vol 327-328 ◽  
pp. 355-358 ◽  
Author(s):  
Borut Bundara ◽  
Masataka Tokuda ◽  
M. Ye
Keyword(s):  
Indirect Method ◽  
Compression Characteristics

scholarly journals Evaluation of sperm quality of Erythrolamprus poecilogyrus sublineatus (Cope, 1860) (Serpentes, Dipsadidae)

2017 ◽  
Vol 77 (3) ◽  
pp. 553-557
Author(s):  
A. C. Silva ◽  
A. S. Varela Junior ◽  
T. F. Cardoso ◽  
E. F. Silva ◽  
D. Loebmann ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Membrane Integrity ◽  
Coastal Region ◽  
Rio Grande ◽  
Rio Grande Do Sul ◽  
Sperm Analysis ◽  
Pampa Region

Abstract Erythrolamprus poecilogyrus sublineatus (Cope, 1860), is a species widely distributed in the Pampa Domain, occurring in Rio Grande do Sul, Argentina and Uruguay, mainlyin the pampa region. In the coastal region of southern Brazil this is serpent is considered one of the most abundant. The purpose of the present study is to describe the techniques of sperm evaluation in vitro for E. poecilogyrus sublineatus in the coastal plain of Rio Grande do Sul, Brazil. After laparatomy the efferent vases were collected and the semen was diluted in 1ml Beltsville Thawing Solution. The characteristics of motility, membrane integrity, mitochondria, acrosome, DNA, cell viability and cellular functionality were evaluated. Fluorescent probes were used for the evaluation of sperm structure in epifluorescence microscope. With the techniques described, it was possible to identify intact and injured cells, enabling the determination of cell characteristics for the spring season (October and November). It was observed in the analyses that 80% of sperm cells were mobile and that 84.1 ± 8.0% of sperm membranes were intact. The standards found were of 48 ± 13.8% of intact acrosome, 73.6 ± 6.0 of perfect DNA and of 91.8 ± 4.0 of functional mitochondria. Thus, these values from the sperm analysis can be used as standards for the species Erythrolamprus poecilogyrus sublineatus.

scholarly journals Phytochemical Screening and Effect of Cymodocea serrulata on HepG2-Human Hepatocellular Carcinoma Cell Line

2020 ◽  
Vol 11 (2) ◽  
pp. 1684-1691
Author(s):  
Kalpana C S ◽  
Kalaivani P ◽  
Vanitha V
Keyword(s):  
Colorimetric Assay ◽  
Coastal Region ◽  
Water Soluble ◽  
Assay Method ◽  
Viable Cells ◽  
South Indian ◽  
Hepatocellular Carcinoma Cell Line ◽  
Human Hepatocellular Carcinoma Cell ◽  
Cymodocea Serrulata

Cymodocea serrulata, a seagrass commonly known as karumbupassi has been used as a food and also as a medicine by coastal region people and by fishermen while traveling in the sea. It is used as a tranquilizer for babies as it has a soothing quality, it helps during pregnancy and against cough and malaria. C.serrulata is seen abundant in South Indian coastal region. Although there is a report on the antibacterial, antioxidant, and anti-inflammatory property of C.serrulata, there are no evident details on phyto-compounds present in it. Invitro antiproliferative test was performed by MTT (methylthiozoltetrazolium) assay method against HePG2 celline of liver cancer cells. MTT assay is a colorimetric assay used for the determination of cell proliferation and cytotoxicity, based on reduction of the yellow colored water soluble tetrazolium dye MTT to formazan crystals. Mitochondrial lactate dehydrogenase produced by liver cells reduces MTT to insoluble formazan crystals, which upon dissolution into an appropriate solvent exhibits purple color, the intensity of which is proportional to the number of viable cells and can be measured spectrophotometrically at 570nm.

scholarly journals Comparison of manually and automatically derived fresh-saline groundwater boundaries from helicopter-borne EM data at the Jade Bay, Northern Germany

2018 ◽  
Vol 54 ◽  
pp. 00032 ◽  
Author(s):  
Bernhard Siemon ◽  
Annika Steuer ◽  
Nico Deus ◽  
Jörg Elbracht
Keyword(s):  
Saline Water ◽  
Coastal Region ◽  
Threshold Values ◽  
Northern Germany ◽  
Lower Saxony ◽  
Saline Groundwater ◽  
Jade Bay ◽  
Federal Institute ◽  
Geophysical Surveys ◽  
Subsurface Sediments

The Federal Institute for Geosciences and Natural Resources (BGR) conducted many airborne geophysical surveys in Northern Germany during the last decades. The coastal regions of Lower Saxony were investigated by frequency-domain helicopter-borne electromagnetics (HEM) to reveal the bulk resistivity of the subsurface (sediments and pore fluids). The State Authority for Mining, Energy and Geology (LBEG) is preparing a statewide “saltwater map” for Lower Saxony with a focus on the coastal aquifers influenced by seawater intrusion. For this purpose, the HEM resistivities are used in combination with groundwater data and a geological model to derive the lower fresh-water boundary. As appropriate depth values are manually picked from vertical resistivity sections, this procedure is time consuming. Therefore, we tested an alternative, which automatically derives the fresh-saline groundwater boundary directly from the HEM resistivity models. The ambiguity between brackish/saline water and clayey sediments as source for low resistivities can somewhat be reduced by the application of gradients instead of threshold values for searching an appropriate boundary. We compare results of both methods using a dataset from a coastal region at the Jade Bay.

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