Sand Mining's Impact on Groundwater in the Vietnamese Mekong Delta

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How sand mining in the Mekong Delta is drawing down groundwater. Riverbed incision caused by sand mining deepens channels and weakens the link between river and aquifer. The authors find groundwater storage and levels declining, particularly where mining is intense. Chengcheng Wu, Edward Park, Dung Duc Tran (HAPRI Senior Research Associate) et al. A farmer crouches at a household tube well on a Mekong Delta riverbank, checking the water level. Behind him, an eroded earthen bank drops to a wide brown river where a sand dredging barge is working and a small wooden boat passes near the far bank.

Sand Mining's Impact on Groundwater in the Vietnamese Mekong Delta

www.hapri.org

Dung Duc Tran — Senior Research Associate

A study co-authored by Dung Duc Tran (HAPRI Senior Research Associate) with colleagues is the first to investigate how sand mining influences groundwater storage and surface water–groundwater interactions in the Vietnamese Mekong Delta. It finds a declining trend in groundwater storage and groundwater levels, particularly in areas of intense mining activity.

Context

Sand mining is a pressing socio-environmental concern in the Vietnamese Mekong Delta, profoundly reshaping river morphology, sediment transport and hydrological processes. Previous research has identified the adverse effects of sand extraction on surface water and channel morphology, but, as the authors note, its impact on groundwater had never been examined.

*What the findings indicate about sand mining*

Methods

The study uses an integrated approach that combines long-term field observations, remote sensing data and hydrological records, and runs spatiotemporal analyses of groundwater storage anomalies and groundwater levels. The authors also propose a conceptual model to illustrate the mechanisms driving the changes they observe.

Key findings

Groundwater levels in the delta's unconfined aquifers declined at a mean rate of 0.03 m/year between 1995 and 2017, ranging from a maximum of 0.09 m/year in the northeast to a minimum of 0.01 m/year at the coastal delta.
Groundwater storage anomalies declined over 20 years in three phases: a sharp decrease (2002–2006, 3.2 × 10⁷ m³/year), a partial recovery (2006–2015, 8 × 10⁶ m³/year) and a slower decline since 2015 (4 × 10⁶ m³/year).
The findings indicate that extensive riverbed incision caused by sand mining deepens channels, disrupts sediment redistribution and accelerates groundwater depletion while reducing aquifer recharge.
As a result, riverbed hydraulic connectivity is weakened, leading to a diminished exchange between surface water and groundwater.

Keywords:

Sand Mining
Vietnamese Mekong Delta
Groundwater Storage
Surface Water-Groundwater Interaction
Riverbed Incision

Link:

https://doi.org/10.1016/j.jhydrol.2026.135874

Citation:

Wu, C., Park, E., Tran, D. D., Wang, J., Duy, N. L., Vasilopoulos, G., & Lu, C. (2026). Impact of sand mining on groundwater-surface water interactions in the Vietnamese Mekong Delta. Journal of Hydrology, 677, 135874.