Analysis of groundwater extraction-related land subsidence analysis in Yangon in comparison with insar results | |
| Author | La Min Ko Ko |
| Call Number | AIT Thesis no.GE-20-12 |
| Subject(s) | Subsidences (Earth movements)--Myanmar--Yangon Groundwater--Myanmar--Yangon Synthetic aperture radar--Myanmar--Yangon |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Geotechnical and Earth Resources Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | This research is a preliminary study of land subsidence analysis for the old capital city, Yangon, of Myanmar. Due to the growing rate of population and industrialization, the demand of water is increasing, and the study area is mostly relying on the groundwater. Therefore, land subsidence due to groundwater pumping is possible but it has not been studied much due to the lack of data and difficulties in data collection, except an analysis by Horst (2017) using satellite image. In this research, around 300 soil investigation borehole data and about 80 hydrogeological borehole data were collected, and keyed in the excel spreadsheet. They were further used to construct hydrogeological and geotechnical databases and for the study area by using RockWorks16. Based on the hydrogeological database, a model of aquifer system was constructed, consisting of Alluvium aquitard, Valley-filled aquifer, Danyingone aquitard, Arzanigone aquifer, Besapat aquitard and Thadugan aquifer. Valley-filled aquifer ranges from 7.6 m to 131 m, Arzanigone aquifer ranges from 42 to 160 m and Thadugan aquifer ranges from 108 to 205 m below the mean sea level. Each aquifer is separated by the aquitards ranging from 10 to 50 m thickness. This aquifer system is used as the geometric model for a computer-aided groundwater modelling by Visual MODFLOW flex 2016 with the maximum estimated pumping rate from (Myint Thein, 2019). The drawdowns from this modelling were used as boundary conditions for the following geotechnical analysis based on the TZP program developed by Giao (1997). The drawdowns read are 7 m and 12 m for North Oakkalapa and North Dagon townships, respectively from the drawdown map of the groundwater modelling. These areas are selected for the subsidence calculation due to the previous INSAR result of potential subsidence. Ten points were selected from the LOS map (Horst, 2017) for consolidation settlements to be compared with the results of INSAR-based analysis by Horst (2017). According from LOS velocity image by Horst (2017), eastern parts of Yangon especially Dagon Myothit and Dawbon areas showed the vertical displacement rate of around 20 mm where in this research, the consolidation analysis of the same area in North Dagon and North Oakkalapa showed not much different results around 8 mm to over 20 mm within the year of 2000 to 2050. However, according to these results and comparisons, the study area has much more potential subsidence in the future. |
| Year | 2021 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Chao, Kuo Chieh;Pham Huy Giao (Co-Chairperson); |
| Examination Committee(s) | Avirut Putiwongrak;Han, Sone; |
| Scholarship Donor(s) | His Majesty the King’s Scholarship (Thailand); |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2021 |