Bangladesh is a densely populated, low-lying, mainly riverine country located in South Asia with a coastline of on the northern littoral of the Bay of Bengal. The delta plain of the Ganges (Padma), Brahmaputra (Jamuna), and Meghna Rivers and their tributaries occupy 79 percent of the country. Four uplifted blocks (including the Madhupur and Barind Tracts in the centre and northwest) occupy 9 percent and steep hill ranges up to approximately high occupy 12 percent in the southeast (the Chittagong Hill Tracts) and in the northeast. Straddling the Tropic of Cancer, Bangladesh has a tropical monsoon climate characterised by heavy seasonal rainfall, high temperatures, and high humidity. Natural disasters such as floods and cyclones accompanied by storm surges periodically affect the country. Most of the country is intensively farmed, with rice the main crop, grown in three seasons. Rapid urbanisation is taking place with associated industrial and commercial development. Exports of garments and shrimp plus remittances from Bangladeshis working abroad provide the country's three main sources of foreign exchange income.
Physical geography
[[File:him.ogg|thumb|Satellite photographs (from Terra-MODIS) and computer-generated models help visualise Bangladesh's place in the world. Located in South Asia, it is virtually surrounded by India and the Bay of Bengal to the south. But in many ways, the country's fate is dominated by the world's highest mountain range looming to the north-the Himalayas.]]
The physical geography of Bangladesh is varied and has an area characterised by two distinctive features: a broad deltaic plain subject to frequent flooding, and a small hilly region crossed by swiftly flowing rivers. The country has an area of (according to BBS 2020) or (according to CIA World factbook 2021) and extends north to south and east to west. Bangladesh is bordered on the west, north, and east by a land frontier with India and, in the southeast, by a short land and water frontier () with Myanmar. On the south is a highly irregular deltaic coastline of about , fissured by many rivers and streams flowing into the Bay of Bengal. The territorial waters of Bangladesh extend , and the exclusive economic zone of the country is .
Roughly 80% of the landmass is made up of fertile alluvial lowland called the Bangladesh Plain. The plain is part of the larger Plain of Bengal, which is sometimes called the Lower Gangetic Plain. Although altitudes up to above sea level occur in the northern part of the plain, most elevations are less than above sea level; elevations decrease in the coastal south, where the terrain is generally at sea level. With such low elevations and numerous rivers, water—and concomitant flooding—is a predominant physical feature. About of the total area of Bangladesh is covered with water, and larger areas are routinely flooded during the monsoon season.
The only exceptions to Bangladesh's low elevations are the Chittagong Hills in the southeast, the Low Hills of Sylhet in the northeast, and highlands in the north and northwest. The Chittagong Hills constitute the only significant hill system in the country and, in effect, are the western fringe of the north–south mountain ranges of Myanmar and eastern India. The Chittagong Hills rise steeply to narrow ridgelines, generally no wider than , with altitudes from above sea level. At altitude, the highest elevation in Bangladesh is found at Saka Haphong, in the southeastern part of the hills. Fertile valleys lie between the hill lines, which generally run north–south. West of the Chittagong Hills is a broad plain, cut by rivers draining into the Bay of Bengal, that rises to a final chain of low coastal hills, mostly below , that attain a maximum elevation of . West of these hills is a narrow, wet coastal plain located between the cities of Chittagong in the north and Cox's Bazar in the south.
About 67% of Bangladesh's nonurban land is arable. Permanent crops cover only 2%, meadows and pastures cover 4%, and forests and woodland cover about 16%. The country produces large quantities of quality timber, bamboo, and sugarcane. Bamboo grows in almost all areas, but high-quality timber grows mostly in the highland valleys. Rubber planting in the hilly regions of the country was undertaken in the 1980s, and rubber extraction had started by the end of the decade. A variety of wild animals are found in the forest areas, such as in the Sundarbans on the southwest coast, which is the home of the royal Bengal tiger. The alluvial soils in the Bangladesh Plain are generally fertile and are enriched with heavy silt deposits carried downstream during the rainy season.