Geoelectrical and Hydrogeological Modeling of the Fresh Water / Saline Water Interface in the Lower Florida Keys

2011 ◽  
Author(s):  
Albert Yeboah‐Forson ◽  
Dean Whitman ◽  
Danielle Ogurrcak ◽  
Mike Sukop
Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1548 ◽  
Author(s):  
Muhammad Hasan ◽  
Yanjun Shang ◽  
Gulraiz Akhter ◽  
Weijun Jin

Groundwater is the main supply of fresh water in many parts of the world. The intrusion of saline water into the fresh water is a serious threat to groundwater resources. Delineation of fresh-saline aquifer zones is essential to exploit the potable fresh water. The conventional method to differentiate fresh-saline water interface is to collect and test groundwater samples from boreholes using a number of laboratory tests. However, such techniques are expensive and time consuming. A non-invasive geoelectrical method, in combination with borehole data and physicochemical analysis, is proposed to assess the fresh-saline aquifers. This investigation was conducted in Jahanian area of Pakistan with forty-five vertical electrical soundings (VES) using Schlumberger array, nine bore wells and fifty physicochemical samples. The fresh-saline aquifers are delineated by aquifer resistivity and Dar-Zarrouk parameters namely transverse unit resistance and longitudinal unit conductance. The aquifer potential of fresh-saline water zones is estimated by the aquifer parameters namely transmissivity and hydraulic conductivity. Integration of subsurface resistivity with hydrogeological information reveals the subsurface formation of five layered succession, that is, topsoil having dry strata with resistivity greater than 30 Ωm, clay containing saline water with resistivity less than 15 Ωm, clay-sand with brackish water having resistivity between 15 and 25 Ωm, sand containing fresh water with resistivity ranging from 25 to 45 Ωm and gravel-sand having fresh water with resistivity greater than 45 Ωm. The geoelectrical columns and geological cross-sections constructed by the aquifer resistivity provide effectiveness of the interpretations for the evaluation of fresh-saline aquifers. The results of physicochemical analysis using WHO guideline validate the fresh-saline aquifer zones delineated by the geophysical method. This investigation contributes towards predicting the fresh-saline water interface using inexpensive geoelectrical method.


2012 ◽  
Vol 212-213 ◽  
pp. 155-162
Author(s):  
Nalaka D. Subasinghe ◽  
Priyantha Jinadasa

Demarcation of fresh- and saline-water interface is important in water supply engineering in coastal regions. A resistivity imager system was employed to investigate the saline water intrusion to freshwater table at selected coastal locations in Sri Lanka. This is the first such attempt in Sri Lanka using the above technique. Systematic geo-resistivity investigations were carried out at randomly selected sites at Mundel and Rekawa coastal areas. Measured and calculated values generally show good agreement, especially in Mundel area, where the current penetration is good. The results indicate a possibility of using resistivity imager system to demarcate the saline and fresh water interfaces and intermixing zones, especially in the wet zone.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 894
Author(s):  
Emad M. Hafez ◽  
Hany S. Osman ◽  
Usama A. Abd El-Razek ◽  
Mohssen Elbagory ◽  
Alaa El-Dein Omara ◽  
...  

The continuity of traditional planting systems in the last few decades has encountered its most significant challenge in the harsh changes in the global climate, leading to frustration in the plant growth and productivity, especially in the arid and semi-arid regions cultivated with moderate or sensitive crops to abiotic stresses. Faba bean, like most legume crops, is considered a moderately sensitive crop to saline soil and/or saline water. In this connection, a field experiment was conducted during the successive winter seasons 2018/2019 and 2019/2020 in a salt-affected soil to explore the combined effects of plant growth-promoting rhizobacteria (PGPR) and potassium (K) silicate on maintaining the soil quality, performance, and productivity of faba bean plants irrigated with either fresh water or saline water. Our findings indicated that the coupled use of PGPR and K silicate under the saline water irrigation treatment had the capability to reduce the levels of exchangeable sodium percentage (ESP) in the soil and to promote the activity of some soil enzymes (urease and dehydrogenase), which recorded nearly non-significant differences compared with fresh water (control) treatment, leading to reinstating the soil quality. Consequently, under salinity stress, the combined application motivated the faba bean vegetative growth, e.g., root length and nodulation, which reinstated the K+/Na+ ions homeostasis, leading to the lessening or equalizing of the activity level of enzymatic antioxidants (CAT, POD, and SOD) compared with the controls of both saline water and fresh water treatments, respectively. Although the irrigation with saline water significantly increased the osmolytes concentration (free amino acids and proline) in faba bean plants compared with fresh water treatment, application of PGPR or K-silicate notably reduced the osmolyte levels below the control treatment, either under stress or non-stress conditions. On the contrary, the concentrations of soluble assimilates (total soluble proteins and total soluble sugars) recorded pronounced increases under tested treatments, which enriched the plant growth, the nutrients (N, P, and K) uptake and translocation to the sink organs, which lastly improved the yield attributes (number of pods plant−1, number of seeds pod−1, 100-seed weight). It was concluded that the combined application of PGPR and K-silicate is considered a profitable strategy that is able to alleviate the harmful impact of salt stress alongside increasing plant growth and productivity.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Muhammad Fauzul Imron ◽  
Setyo Budi Kurniawan ◽  
Siti Rozaimah Sheikh Abdullah

AbstractLeachate is produced from sanitary landfills containing various pollutants, including heavy metals. This study aimed to determine the resistance of bacteria isolated from non-active sanitary landfill leachate to various heavy metals and the effect of salinity levels on the removal of Hg by the isolated bacterium. Four dominant bacteria from approximately 33 × 1017 colony-forming units per mL identified as Vibrio damsela, Pseudomonas aeruginosa, Pseudomonas stutzeri, and Pseudomonas fluorescens were isolated from non-active sanitary landfill leachate. Heavy metal resistance test was conducted for Hg, Cd, Pb, Mg, Zn, Fe, Mn, and Cu (0–20 mg L− 1). The removal of the most toxic heavy metals by the most resistant bacteria was also determined at different salinity levels, i.e., fresh water (0‰), marginal water (10‰), brackish water (20‰), and saline water (30‰). Results showed that the growth of these bacteria is promoted by Fe, Mn, and Cu, but inhibited by Hg, Cd, Pb, Mg, and Zn. The minimum inhibitory concentration (MIC) of all the bacteria in Fe, Mn, and Cu was > 20 mg L− 1. The MIC of V. damsela was 5 mg L− 1 for Hg and >  20 mg L− 1 for Cd, Pb, Mg, and Zn. For P. aeruginosa, MIC was > 20 mg L− 1 for Cd, Pb, Mg, and Zn and 10 mg L− 1 for Hg. Meanwhile, the MIC of P. stutzeri was > 20 mg L− 1 for Pb, Mg, and Zn and 5 mg L− 1 for Hg and Cd. The MIC of P. fluorescens for Hg, Pb, Mg, and Zn was 5, 5, 15, and 20 mg L− 1, respectively, and that for Cd was > 20 mg L− 1. From the MIC results, Hg is the most toxic heavy metal. In marginal water (10‰), P. aeruginosa FZ-2 removed up to 99.7% Hg compared with that in fresh water (0‰), where it removed only 54% for 72 h. Hence, P. aeruginosa FZ-2 is the most resistant to heavy metals, and saline condition exerts a positive effect on bacteria in removing Hg.


1996 ◽  
Vol 180 (1) ◽  
pp. 87-95 ◽  
Author(s):  
S. E. Benes ◽  
R. Arag��s ◽  
R. B. Austin ◽  
S. R. Grattan
Keyword(s):  

1999 ◽  
Author(s):  
Yunus Çerçi ◽  
Yunus A. Çengel ◽  
Byard Wood

Abstract A general relation is obtained for the minimum work input requirement for desalination processes using the second-law of thermodynamics. The relation developed can be used to determine the minimum work input for any salinity of the incoming water, and the recovery ratio. It is also shown that there is a lower and an upper limit for the minimum work, corresponding to recovery ratios of 0% and 100%, respectively. The minimum work input per unit mass of fresh water produced is determined for various salinities of incoming water, and the salinities of fresh water produced, and the results are tabulated and plotted. It is shown that the minimum work is a strong function of salinity, and increases with salinity and the recovery ratio. It is also shown that the minimum work input requirement remains fairly constant for recovery ratios of up to about 80%; the minimum work increases drastically at high recovery ratios; and an optimum value of recovery ratio exists to minimize the power consumption of actual desalination plants. But the value of this optimum recovery ratio decreases with increasing salinity of the incoming saline water. The results presented in this paper can be used as a basis to evaluate the performance of actual desalination plants.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ogalo Baka Oluoch ◽  
Esther Mwende Muindi ◽  
Elisha Otieno Gogo

Salinity is a major biotic factor that negatively affects growth and yield of crops. Over 90% of the coastal region of Kenya is arid and semi-arid, most farmers in the region use borehole irrigation water which is saline. Amaranthus spp. is one of the main vegetables grown in coastal region. There is limited information regarding the effect of salinity on amaranthus production. The study sought to determine the effect of saline irrigation water on amaranthus growth in coastal Kenya. Two experiments were set up, one at Mivumoni Secondary School farm in Kwale County and another at Pwani University farm in Kilifi County from beginning of September 2019 to the end of January, 2020. The experiments were laid out in a randomized complete block design and replicated three times. The six treatments tested were: fresh water alone, 75% saline water alone, 100% saline water alone, fresh water + DAP, 75% saline water + DAP, 100% saline water + DAP. Crop growth data collected were: emergence rate, plant height, leaf number, leaf area, chlorophyll content, stem thickness, root density, root weight, root volume and total plant biomass. Data obtained were subjected to analysis of variance using SAS statistical package (SAS, Version 10) and treatment effects were tested for significance using F-test. Significant means at F-test was ranked using Tukey’s test at 5% level of significance. Amaranthus seeds sown in fresh water had higher emergence rate compared to seeds sown in saline water. Salinity regardless of concentration used and application of DAP, resulted in decrease in height, leaf number, leaf area, stem tickness, chlorophyll content, root length, root weight, root volume and total biomass. The study demonstrates that saline irrigation water in coastal Kenya has a negative effect on Amaranthus growth.


2022 ◽  
Author(s):  
Ranjan Sinha ◽  
Shalivahan Shrivastava

Abstract Saltwater intrusion and up coning in coastal aquifer is a common phenomenon brought either due to flow of seawater into freshwater aquifer originally caused by groundwater abstraction near the coast or due to wrong casing design of water wells. This necessitates a study of aquifer disposition along with demarcation of fresh water saline water interface of Kasai River basin, Eastern India to determine the depth to freshwater and recommend the borehole design. In this study geophysical and hydrogeological techniques were employed to map to demarcate fresh and saline water interface. The phenomenon of saline water up coning is also noticed and accordingly water wells have been designed. For the said study, twenty two geophysical logs, sixty five lithological logs and hydrogeological data of eighty eight sites spread across Kasai River basin were utilized. The study shows that there are three regional aquifers exist in the area. It is recommended that water wells in the study area is to be constructed with artificial gravel packing of size 2-3mm and screen slot size is suggested to be 1.2mm. Since the sites are affected with saline water, hence isolation of zone is mandatory with proper cementing material or packer. This research work is able to develop a design model for the boreholes located in the area. The work as a whole will serve as a vital role in scientific management of groundwater resource and enable the rational planning in coastal aquifers so as to avoid fresh and saline water intermixing and up-coning.


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