Skip to main content
Publications | Persons | Institutes | Projects
[ report an error in this record ]basket (0): add | show Print this page

Imaging the structure and the saltwater intrusion extent of the Luy River coastal aquifer (Binh Thuan, Vietnam) using electrical resistivity tomography
Cong-Thi, D.; Dieu, L.P.; Thibaut, R.; Paepen, M.; Ho, H.H.; Nguyen, F.; Hermans, T. (2021). Imaging the structure and the saltwater intrusion extent of the Luy River coastal aquifer (Binh Thuan, Vietnam) using electrical resistivity tomography. Water 13(13): 1743. https://dx.doi.org/10.3390/w13131743
In: Water. MDPI: Basel. e-ISSN 2073-4441, more
Peer reviewed article  

Available in  Authors 

Author keywords
    saltwater intrusion; aquifer; resistivity; salinity; geophysics

Authors  Top 

Abstract
    With the growing population and the adverse effects of climate change, the pressure on coastal aquifers is increasing, leading to a larger risk of saltwater intrusion (SI). SI is often complex and difficult to characterize from well data only. In this context, electrical resistivity tomography (ERT) can provide high-resolution qualitative information on the lateral and vertical distribution of salinity. However, the quantitative interpretation of ERT remains difficult because of the uncertainty of petrophysical relationships, the limitations of inversion, and the heterogeneity of aquifers. In this contribution, we propose a methodology for the semiquantitative interpretation of ERT when colocated well data are not available. We first use existing wells to identify freshwater zones and characterize the resistivity response of clayey deposits. Then, we approximate the formation factor from water samples collected in the vicinity of ERT data to derive a resistivity threshold to interpret the saline boundary. We applied the methodology in the shallow aquifers of the Luy River in the Binh Thuan province, Vietnam, where water resources are under pressure due to agricultural, aquacultural, and industrial production. Twenty-one ERT profiles were collected and revealed a much larger intrusion zone, compared to the previous study. Saltwater is present in lowland areas of the left bank over almost the whole thickness of the aquifer, while the right bank is constituted of sand dunes that are filled with freshwater. At a larger distance from the sea, a complex distribution between fresh and saltwater is observed. Our methodology could be applied to other heterogeneous aquifers in the absence of a dense monitoring network.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors