Geography

Thailand lies in Southeast Asia, with Laos and Cambodia to its east, the Gulf of Thailand and Malaysia to its south, and the Andaman Sea and Myanmar to its west. At 513,000 sq km (198,000 sq mi), Thailand is the world's 49th-largest country, and is comparable in size to Spain.

Regions

Landforms and drainage divide the country more or less into four natural regions: the North, the Northeast, Central, and the South. Although Bangkok geographically is part of the central plain, as the capital and largest city this metropolitan area may be considered in other respects a separate region. Each of the four geographical regions differs from the others in population, basic resources, natural features and level of social and economic development. The diversity of the regions is in fact the most pronounced attribute of Thailand's physical setting.

North Thailand

These high mountains are incised by steep river valleys and upland areas that border the central plain. A series of rivers, including the Nan, Ping, Wang, and Yom, unite in the lowlands to form the Chao Phraya watershed. Traditionally, these natural features made possible several different types of agriculture, including wet-rice farming in the valleys and shifting cultivation in the uplands. The forested mountains also promoted a spirit of regional independence. Forests, including stands of teak and other economically useful hardwoods that once dominated the North and parts of the Northeast, had diminished by the 1980s to 130,000 sq km. In 1961, they covered 56 % of the country, but by the mid-1980s forestland had been reduced to less than 30 % of Thailand's total area.

Northeast Thailand

The Northeast, with its poor soils, is not favoured agriculturally. The region consists mainly of the dry Khorat Plateau and a few low hills. The short monsoon season brings heavy flooding in the river valleys. Unlike the more fertile areas of Thailand, the Northeast has a long dry season, and much of the land is covered by sparse grasses. Mountains ring the plateau on the west and the south, and the Mekong delineates much of the eastern rim.

Central Thailand

The 'heartland', Central Thailand, is a natural self-contained basin often termed 'the rice bowl of Asia.' The complex irrigation system developed for wet-rice agriculture in this region provided the necessary economic support to sustain the development of the Thai state from the 13th century Sukhothai kingdom to contemporary Bangkok. Here the rather flat unchanging landscape facilitated inland water and road transport. The fertile area was able to sustain a dense population, 422 persons per square kilometre in 1987, compared with an average of 98 for the country as a whole. The terrain of the region is dominated by the Chao Phraya and its tributaries and by the cultivated paddy fields. Metropolitan Bangkok, the focal point of trade, transport and industrial activity, is situated on the southern edge of the region at the head of the Gulf of Thailand and includes part of the delta of the Chao Phraya system.

South Thailand

The South, a narrow peninsula, is distinctive in climate, terrain and resources. Its economy is based on rice cultivation for subsistence and rubber production for industry. Other sources of income include coconut plantations, tin mining and tourism, which is particularly lucrative on Phuket Island. Rolling and mountainous terrain and the absence of large rivers are conspicuous features of the South. North-south mountain barriers and impenetrable tropical forest caused the early isolation and separate political development of this region. International access through the Andaman Sea and the Gulf of Thailand made the South a crossroads for both Theravada Buddhism, centred at Nakhon Si Thammarat, and Islam, especially in the former Pattani kingdom on the border with Malaysia.

Topography and Drainage

The most conspicuous features of Thailand's terrain are high mountains, a central plain and an upland plateau. Mountains cover much of northern Thailand and extend along the Myanmar border down through the Kra Isthmus and the Malay Peninsula. The central plain is a lowland area drained by the Chao Phraya River and its tributaries, the country's principal river system, which feeds into the delta at the head of the Bay of Bangkok. The Chao Phraya system drains about one-third of the nation's territory. In the northeastern part of the country the Khorat Plateau, a region of gently rolling low hills and shallow lakes, drains into the Mekong through the Mun River. The Mekong system empties into the South China Sea and includes a series of canals and dams.

Together, the Chao Phraya and Mekong systems sustain Thailand's agricultural economy by supporting wet-rice cultivation and providing waterways for the transport of goods and people. In contrast, the distinguishing natural features of peninsular Thailand are long coastlines, offshore islands, and diminishing mangrove swamps.