Short answers, pulled from the story.
King Phutthayotfa Chulalok moved the capital to Rattanakosin Island and erected the City Pillar on the 21st of April 1782. This date marks the official founding of Bangkok as the capital of Siam.
The city sits in the Chao Phraya River delta at an average elevation of just one meter above sea level. Most of the area was originally swampland drained and irrigated for agriculture via canals built between the 16th and 19th centuries.
A study by the OECD estimated 5.138 million people could face coastal flooding by 2070. Another study published in October 2019 concluded up to 12 million Thais in the greater metropolitan area face annual flooding events.
In 2022 Bangkok generated an economic output of 5.747 trillion baht equaling US$164 billion. This amounted to a per-capita GDP value of 634,109 baht more than twice the national average.
Euromonitor International named it the world's best tourist destination in 2017 welcoming a record 32.4 million visitors. Of 162 cities worldwide, Bangkok topped rankings for four consecutive years from 2010 to 2013 according to Travel + Leisure magazine.