Imaging the extent of salt water intrusion in the Luy river coastal aquifer (Binh Thuan) using electrical resistivity tomography (ERT)
| Autor: | Cong-Thi, Diep, Pham Dieu, Linh, Robin Thibaut, Nguyen, Frédéric, Marieke Paepen, Hieu Ho, Huu, Hermans, Thomas |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Young Researchers' Overseas Day, 4th edition, Abstracts Ghent University Academic Bibliography |
| Popis: | Binh Thuan is one of the driest provinces in Vietnam. During the dry season, seawater intrudes through estuaries and threatens groundwater resources. The latter is under increasing pressure due to water extraction for agri- and aquaculture. To evaluate the current state of salinity in the shallow coastal aquifer, electrical resistivity tomography (ERT) measurements were collected along the downstream part of the Luy river. 21 profiles were collected in July-August 2019 based on the previous saltwater intrusion boundary which was estimated from water samples collected from shallow boreholes in the area. The data were processed to get the resistivity distribution of the subsurface. The results show that resistivity zones lower than 10 Ohm.m and corresponding to saltwater dominate in lowland areas with almost the entire thickness of the aquifer filled with brackish to saltwater. On the right bank of the river, the higher elevation dune area contains a freshwater aquifer which limits the intrusion of saltwater. At shallower depths, the aquifer displays a complex distribution of fresh and saline lenses. Those variations are correlated with the soil occupation (types of culture) and the irrigation practices. ERT data also reveals the depth of the rock basement. The geophysical observations show that the extension of saltwater intrusions is much larger than expected from existing borehole data and is not limited to interaction with the river. |
| Databáze: | OpenAIRE |
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