Earthquake Building Collapse Risk Estimation for 2040 in Yangon, Myanmar

Myanmar is a thriving country in Southeast Asia and is facing future earthquake risks caused by the Sagaing Fault. Under these circumstances, Yangon must implement earthquake risk reduction measures in future development. Applying the building collapse risk evaluation method proposed by the Tokyo Metropolitan Government, and analyzing current and future urban conditions of Yangon City based on available datasets, this study aimed to (1) evaluate present urban vulnerability focusing on building collapse risk, (2) clarify its future expansion tendency based on residential area development conditions from 2004 to 2018, and (3) estimate future building collapse risk in terms of future urban expansion limitation with urban function and building vulnerability in order to obtain useful information on earthquake risk reduction for future development in Yangon. Mainly, this research clarified as follows: (1) The inventory provided by YCDC (Yangon City Development Committee) showed that wooden buildings and RC accounted for 93.8% of all buildings in Yangon. (2) In order to understand the present urban vulnerability of Yangon based on the Tokyo Metropolitan Government's method, 567 objective wards were categorized into five ranks according to the building collapse risk value. It indicated that building collapse risk in the Dawpon and Tharkayta Townships, located on the west side of Pazundaung Creek, were the highest. Some newly developed outskirts areas, such as Hlaingtharyar or Dala, also appeared as vulnerable with Ranks 4 and 5. (3) Yangon's urban development conditions from 2004 to 2018 were visually clarified. Then, the relationships between the number of buildings, residential district area, and population according to townships were analyzed to estimate future development. (4) Finally, two types of urban development scenarios were set: Scenario A based on urban expansion limitation and urban function, and Scenario B based on building vulnerability. Then, the future building collapse risk trend from 2014 until 2040 was estimated. It was found that the Sub-center System would deter future urban sprawl in the future more than the Super CBD Single-core System, and the number of damaged buildings can be reduced by 43.5% at most in Dagon Seikkan.