Over ons
  Consultancy     Participaties     Vastgoed     Contact  
Producten en Diensten
Thesis Wouter Goofers (2016)
Thesis Wouter Goofers (2019)
Thesis Wouter Goofers (2020)

Paleo-hydrogeographic reconstruction of the groundwater salinity in the Ayeyarwady Delta, Myanmar, using a 3D variable-density groundwater model

Thesis Wouter Goofers MSc, July 2020


River deltas, in general densely populated, facilitate the needs of a large part of the world’s population. One of the underlying reasons is their inherent high quality and easily obtained fresh water supply, mostly in the form of groundwater. Considering their socio-economic status, securing groundwater as a natural resource for the future is therefore important. To improve the understanding of imposed pressures that influence the groundwater regime, hydrogeological modelling can be an insightful tool. However, necessary input data to run such models are not always readily available. In this MSc research, a previously constructed 3D variable-density groundwater flow model of the Ayeyarwady Delta was enhanced to serve the Regional Water Security Study (RWSS) in Myanmar. This RWSS study aims to formulate measures for the near future concerning freshwater security. Using regionally collected and processed data, in combination with literature research and fieldwork, improvements were realized through the addition of a voxel model of the local hydrogeology and a groundwater extraction component, as well as the performance of a “paleo-reconstruction”, considering the past 130 kyears during which sea levels fluctuations were inserted. A comparison was made between the calculated changes in future hydraulic head and groundwater salinity for the expected changes in groundwater extractions and climate change induced sea level rise and recharge until 2050 to determine the Ayeyarwady Delta groundwater regime’s relative sensitivity to these individual and combined climate and anthropogenic stresses.

The results indicate residual saline groundwater pockets from preceding transgression have been removed almost completely before reaching the sea level of 7000 BP (equal to present-day sea level). Subsequent modelling of a shortened paleo-reconstruction of 6425 year provided almost identical results, suggesting that paleo-reconstructive modelling is sufficiently accurate in predicting the initial salinity distribution when modelled from the moment the first transgression exceeds present-day sea level. Neglecting to include the effects of sea-level rise in modelling delta groundwater development resulted in an overestimation of the fresh groundwater supply by roughly 33% (≈ 695 km3 ) and therefore might be considered injudicious.

Within the foreseeable future, a decrease in recharge, a sea-level rise due to climate change ánd an increase in groundwater extraction due to population growth and increased agricultural development are expected. Modelling efforts suggest salinization will be largest through sea-level rise, affecting the entire coastal region up to 15 km inward, being most felt to the southwest of the Ayeyarwady Delta. Recharge reductions on the other hand are expected to be dominant land inwards, playing only a minor contributing role in salinization of fresh groundwater reserves when compared to sea-level rise. Effects of groundwater extractions are more localized to regions with drawdowns scattered throughout the middle and upper Ayeyarwady Delta and surrounding the cities of Myaungmya and Yangon. However, the intensity of modelled extractions was most likely underestimated when compared to well-log measurements (indicating drawdowns up to 20 meters and beyond) and literature estimates, thus potentially causing the dissociation with increased salinization of the modelling results.

Considering an estimated 50% of the population being dependent on groundwater, sustainable management is indispensable to safeguard fresh groundwater availability. Vital in establishing currently absent groundwater regulatory procedures will be appropriate legislation, improved data collection and especially the (public and open) availability thereof. Meanwhile, awaiting conclusive research with respect to extraction activities, prudence is required

Download Thesis van Wouter Goofers MSc

Uw naam
E-Mail *