Articles | Volume 372
Proc. IAHS, 372, 73–76, 2015
https://doi.org/10.5194/piahs-372-73-2015
Proc. IAHS, 372, 73–76, 2015
https://doi.org/10.5194/piahs-372-73-2015

  12 Nov 2015

12 Nov 2015

Assessing the potential of the multi-aquifer subsurface of the Mekong Delta (Vietnam) for land subsidence due to groundwater extraction

P. S. J. Minderhoud1,2, G. Erkens1,2, V. H. Pham1,2,3, B. T. Vuong3, and E. Stouthamer1 P. S. J. Minderhoud et al.
  • 1Department of Physical Geography, Utrecht University, Utrecht, the Netherlands
  • 2Department of Subsurface and Groundwater Systems, Deltares Research Institute, Utrecht, the Netherlands
  • 3Division of Water Resources Planning and Investigation for the South of Vietnam (DWRPIS), Ho Chi Minh City, Vietnam

Abstract. Land subsidence rates of ~ 1–4 cm yr−1 are measured in the low-lying Vietnamese Mekong Delta. These relatively high subsidence rates are attributed to groundwater extraction, which has increased drastically over the past decades due to growing domestic, agricultural and industrial demands. As a result, hydraulic heads in aquifers are dropping, on average 0.3–0.7 m yr−1. There is an urgent need to go from measurements to predictions in order to test possible future groundwater management scenarios and to reduce the increase of flood risk, salt water intrusion and, on the longer term, prevent the delta from drowning. In this study, we aim to assess the subsidence potential of the multi-aquifer subsurface of the Mekong delta due to groundwater extraction. The first step is to gain a thorough understanding of the complex sedimentary architecture of the heterogeneous subsurface. Combined with the related geotechnical properties, the subsurface build-up determines the subsidence potential. Here, we present our approach to develop a 3-D geo-hydrological model based on lithological borehole data, geophysical sedimentary properties, palaeogeography and conceptual models of delta evolution.

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Short summary
Land subsidence rates of ~1-4 cm yr-1 are measured in the low-lying Vietnamese Mekong Delta. These relatively high subsidence rates are attributed to groundwater extraction, which has increased drastically over the past decades. There is an urgent need to go from measurements to predictions to test future groundwater management scenarios and reduce subsidence. In this study, we present an approach to build a 3D geo-hydrological model to determine the subsidence potential of the Mekong Delta.