Introduction

The largest city in Thailand — its capital Bangkok — has expanded rapidly from its original location along the banks of the Chao Phraya river, some 20 km from the Gulf of Thailand. The city is sited in the midst of a flood plain which is the rice bowl of the country. Since the economic boom in the 1980s, foreign direct investment has flooded into Bangkok, resulting in turn in a boom in the development of residential housing estates, office buildings, factories, hotels and golf courses. There has been a rapid extension of inner city districts, metropolitan suburbs and provincial boundaries. Not surprisingly, the Bangkok Metropolitan Administrative area has now been designated the Bangkok Metropolitan Region or BMR and is effectively not just a mega-city anymore but a mega-urban region. Spanning some 1,567.8 sq km, the urban region comprises five provinces that have become an emergent economically integrated area. This is urban growth of enormous dimension from the original 4 sq km that Bangkok occupied at the time of its founding in 1882.

By the late 1980s, the population of the so-called Bangkok Metropolitan Region (BMR) had been estimated at 7.7 million people and some 2.2 million households. Bangkok has been held up as an example of the archetypal primate city, that is, the type of cities dominating the urban hierarchy in developing countries.

The best infrastructure together with economic growth and development have been concentrated in Bangkok. This explains in part why some 60 per cent of the urban population of Thailand live in Bangkok. In contrast, the next largest city in Thailand in the urban hierarchy is almost twenty times smaller in terms of population.

Located on the flood plain of the country's major river, Bangkok faces major environmental challenges apart from those concerning basic needs such as housing. During the monsoon season, the city is regularly flooded because of heavy rain and high water levels in the river. The situation is worsened by considerable land subsidence due to the long-standing practice of extraction of ground water as well as large-scale and indiscriminate filling in and obstruction of the canals running through the city. This formerly extensive system of canals (klongs) was an important drainage network leading into the Chao Phraya. Many have been filled in to serve as roads since motorized land transport has overtaken the use of water transport in the city.