Abstract

A protocol is presented to perform bulk magnetic susceptibility (BMS) analysis of simulated seawater/saline water using MFK2-FA Multi-Function Kappabridge instrument at Laboratory for Analyses of Magnetic and Petrofabric (LAMP), BHU to obtain a correlation between BMS and hydrogeological data such as salinity and conductivity. This LAMP-BHU Protocol involves the preparation of simulated saline water. It has been developed after BMS measurement of 20 simulated seawater samples in different frequencies, i.e., F1 (976 Hz), F2 (3904 Hz), and F3 (15616 Hz) to prepare a standard data. This standard data is further validated with field data. Fourteen water samples are collected from the field, and hydrogeological data (salinity and conductivity) and BMS at three different frequencies were measured. Further linear regression analysis is performed on the measured data. This protocol yields efficient results with F3, followed by F1 and F2 having an R² value of 0.84, 0.60, and 0.54, respectively, for salinity, and 0.79, 0.51, and 0.40, respectively, for conductivity. Salinity and conductivity are showing a negative trend with all the frequencies. This protocol enables to delineate saline water intruded zone or extent of saline intrusion using BMS analysis. The proposed protocol is a rapid and efficient mode of determination of the saline water intruded zones in the coastal aquifers for prioritisation of groundwater assets facilitating freshwater availability in coastal areas.

Research highlights

• Protocol is developed for Saline water intrusion studies using magnetic susceptibility measurements.

• Magnetic susceptibility, salinity and conductivity was measured for simulated and field samples.

• Inverse relationship observed between magnetic susceptibility w.r.t. salinity and conductivity.

• High frequency magnetic susceptibility provides better results for gradual increase in salinity.

中文翻译：

---

咸水入侵问题的磁化率研究：LAMP-BHU 协议

摘要

提出了使用 MFK2-FA 多功能 Kappabridge 仪器在 BHU 磁性和石油织物分析实验室 (BHU) 对模拟海水/盐水进行体磁化率 (BMS) 分析的协议，以获得 BMS 与水文地质数据之间的相关性如盐度和电导率。这个LAMP-BHU 协议涉及模拟盐水的制备。它是在 BMS 测量不同频率的 20 个模拟海水样本后开发的，即 F1 (976 Hz)、F2 (3904 Hz) 和 F3 (15616 Hz)，以准备标准数据。该标准数据通过现场数据进一步验证。从现场收集了 14 个水样，并测量了三个不同频率下的水文地质数据（盐度和电导率）和 BMS。对测量数据进行进一步的线性回归分析。该协议使用 F3 产生有效结果，然后 F1 和 F2 具有R ²盐度分别为 0.84、0.60 和 0.54，电导率分别为 0.79、0.51 和 0.40。盐度和电导率在所有频率下都显示出负趋势。该协议能够使用 BMS 分析来描绘盐水侵入区或盐水侵入的程度。拟议的协议是一种快速有效的确定沿海含水层咸水侵入区的模式，用于对促进沿海地区淡水供应的地下水资产进行优先排序。

研究亮点

• 使用磁化率测量为盐水入侵研究开发了协议。

• 测量了模拟样品和现场样品的磁化率、盐度和电导率。

• 观察到磁化率与盐度和电导率之间的反比关系。

• 高频磁化率为盐度逐渐增加提供了更好的结果。