scholarly journals Using hydraulic head, chloride and electrical conductivity data to distinguish between mountain-front and mountain-block recharge to basin aquifers

2018 ◽  
Vol 22 (2) ◽  
pp. 1629-1648 ◽  
Author(s):  
Etienne Bresciani ◽  
Roger H. Cranswick ◽  
Eddie W. Banks ◽  
Jordi Batlle-Aguilar ◽  
Peter G. Cook ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Arid Regions ◽  
South Australia ◽  
Hydraulic Head ◽  
Mountain Front ◽  
Quaternary Aquifers ◽  
Groundwater Systems ◽  
Flow Directions ◽  
Electrical Conductivity Data

Abstract. Numerous basin aquifers in arid and semi-arid regions of the world derive a significant portion of their recharge from adjacent mountains. Such recharge can effectively occur through either stream infiltration in the mountain-front zone (mountain-front recharge, MFR) or subsurface flow from the mountain (mountain-block recharge, MBR). While a thorough understanding of recharge mechanisms is critical for conceptualizing and managing groundwater systems, distinguishing between MFR and MBR is difficult. We present an approach that uses hydraulic head, chloride and electrical conductivity (EC) data to distinguish between MFR and MBR. These variables are inexpensive to measure, and may be readily available from hydrogeological databases in many cases. Hydraulic heads can provide information on groundwater flow directions and stream–aquifer interactions, while chloride concentrations and EC values can be used to distinguish between different water sources if these have a distinct signature. Such information can provide evidence for the occurrence or absence of MFR and MBR. This approach is tested through application to the Adelaide Plains basin, South Australia. The recharge mechanisms of this basin have long been debated, in part due to difficulties in understanding the hydraulic role of faults. Both hydraulic head and chloride (equivalently, EC) data consistently suggest that streams are gaining in the adjacent Mount Lofty Ranges and losing when entering the basin. Moreover, the data indicate that not only the Quaternary aquifers but also the deeper Tertiary aquifers are recharged through MFR and not MBR. It is expected that this finding will have a significant impact on the management of water resources in the region. This study demonstrates the relevance of using hydraulic head, chloride and EC data to distinguish between MFR and MBR.

scholarly journals Using hydraulic head, chloride and electrical conductivity data to distinguish between mountain-front and mountain-block recharge to basin aquifers

2017 ◽  
Author(s):  
Etienne Bresciani ◽  
Roger H. Cranswick ◽  
Eddie W. Banks ◽  
Jordi Batlle-Aguilar ◽  
Peter G. Cook ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Resource Management ◽  
Stream Water ◽  
Empirical Relationship ◽  
Hydraulic Head ◽  
Conductivity Data ◽  
Data Set ◽  
Mountain Front ◽  
Electrical Conductivity Data ◽  
Front Zone

Abstract. Numerous basin aquifers in arid and semi-arid regions of the world derive a significant portion of their recharge from adjacent mountains. Recharge can effectively occur through either stream infiltration in the mountain front zone (mountain-front recharge, MFR) or subsurface flow from the mountain (mountain-block recharge, MBR). While a thorough understanding of the recharge mechanisms is critical for water resource management, distinguishing between MFR and MBR is typically difficult. Here we present a relatively simple approach that uses hydraulic head, chloride and electrical conductivity data to distinguish between MFR and MBR. These types of data are inexpensive to measure, and in many cases are readily available from hydrogeological databases. In principle, hydraulic head can inform on groundwater flow directions and stream-aquifer interactions, while chloride can help to distinguish between different groundwater pathways if the sources have distinct concentrations. Electrical conductivity values can be converted to chloride concentrations using an empirical relationship, and hence can be used in a similar manner to chloride, thereby significantly increasing the data set. The practical feasibility and effectiveness of this approach are tested through the case study of the Adelaide Plains basin, South Australia, for which a wealth of historical groundwater level, chloride and electrical conductivity data is available. Hydraulic head data suggest that streams are gaining in the adjacent Mount Lofty Ranges and losing when entering the basin. They also indicate that not only the Quaternary sediments but also the underlying Tertiary sediments receive significant recharge from stream leakage in the mountain front zone. Chloride data also reveal clear spatial patterns suggesting that MFR dominates recharge of the low salinity groundwater found in the basin. This interpretation is further supported by stream water chloride analysis. This study demonstrates that both hydraulic head and chloride data can be effectively used to distinguish between MFR and MBR.

scholarly journals Coastal groundwater systems: mapping chloride distribution from borehole and geophysical data

Grundwasser ◽  
2021 ◽  
Author(s):  
Mohammad Azizur Rahman ◽  
Qian Zhao ◽  
Helga Wiederhold ◽  
Nico Skibbe ◽  
Eva González ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Groundwater Resources ◽  
Integrated Approach ◽  
Horizontal Distribution ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Complex Nature ◽  
Groundwater Systems ◽  
Systems Mapping ◽  
Electrical Conductivity Data

AbstractInformation on chloride (Cl) distribution in aquifers is essential for planning and management of coastal zone groundwater resources as well as for simulation and validation of density-driven groundwater models. We developed a method to derive chloride concentrations from borehole information and helicopter-borne electromagnetic (HEM) data for the coastal aquifer in the Elbe-Weser region where observed chloride and electrical conductivity data reveal that the horizontal distribution of salinity is not uniform and does not correlate with the coastline. The integrated approach uses HEM resistivity data, borehole petrography information, grain size analysis of borehole samples as well as observed chloride and electrical conductivity to estimate Cl distribution. The approch is not straightforward due to the complex nature of the geology where clay and silt are present. Possible errors and uncertainties involved at different steps of the method are discussed.

ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

2020 ◽  
pp. 15-27
Keyword(s):  
Electrical Conductivity ◽  
Humic Acids ◽  
Release Rate ◽  
Release Kinetics ◽  
Sodium Adsorption Ratio ◽  
Salt Affected Soil ◽  
Two Factors ◽  
Dissolved Ions ◽  
Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

“Consideration of patients as networked units to identify opportunities and motivation to enhance capability”: A mixed methods study to explore a personalised Digital Health Hub Model of Care for hip fractures in South Australia (Preprint)

2021 ◽  
Author(s):  
Lalit Yadav ◽  
Tiffany K Gill ◽  
Anita Taylor ◽  
Jen DeYoung ◽  
Mellick J Chehade
Keyword(s):  
Hip Fractures ◽  
Digital Health ◽  
Family Members ◽  
South Australia ◽  
Aged Care ◽  
Mixed Methods Study ◽  
Residential Aged Care ◽  
Model Of Care ◽  
Factors Influencing

UNSTRUCTURED Introduction Majority of older people with hip fractures once admitted to acute hospital care are unable to return to their pre-fracture level of independence and a significant number are either newly admitted or return to residential aged care. Patient education involves family members and/or residential aged care staff as networked units, crucial for empowerment through improving health literacy. Advancement of digital technology has led to evolving solutions around optimising health care including self-management of chronic disease conditions and telerehabilitation. The aim of this study is to understand perspectives of older patients with hip fractures, their family members and residential aged carers, to inform the development of a digitally enabled model of care using a personalised digital health hub (pDHH). Methods A mixed methods study was conducted at a public tertiary care hospital in South Australia involving patients aged 50 years and above along with their family members and residential aged carers. Quantitative data, including basic demographic characteristics, access to computers and Internet were analysed using descriptive statistics. Spearman’s Rank Order Correlation was used to examine correlations between the perceived role of a pDHH in improving health and likelihood of subsequent usage. Whereas qualitative data included series of open-ended questions and findings were interpreted using constructs of capability, opportunity and motivation to help understand the factors influencing the likelihood of potential pDHH use Results Overall, 100 people were recruited in the study, representing 55 patients, 13 family members and 32 residential aged carers. The mean age of patients was 76.4 years (SD-8.4, age range 54-88) and females represented 60% of patients. Although a moderate negative correlation existed with increasing age and likelihood of pDHH usage (ρ= -0.50, p<0.001) the perceived role of the DHH in improving health had a strong positive correlation with the likelihood of pDHH usage by self (ρ=0.71, p<0.001) and by society, including friends and family members (ρ=0.75, p<0.001). Of particular note, almost all the patients (98%) believed they had a family member or friend /carer who would be able to help them to use a digital health platform. Whereas our qualitative findings suggest emphasising on complex interplay of capability, opportunity and motivation as crucial factors while designing a pDHH enabled model of care for hip fractures at a local context level. Conclusion Findings from this study contributed to understand the dynamics around capabilities, motivation and opportunities of patients, family members and formal carers as a “patient networked unit”. Future research recommendation must involve co-creation guided by iterative processes through improving understanding of factors influencing development and successful integration of complex digital healthcare interventions in real-world scenarios.

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