II.

Geography of Southeast Asia

The largest part of mainland Southeast Asia is Indochina, containing half of Southeast Asia’s countries: Cambodia, Laos, Myanmar, Thailand, and Vietnam. The Indochinese Peninsula consists largely of a series of mountain ranges that radiate from the eastern Himalayas and are separated by the valleys and deltas of several major rivers. The Irrawaddy flows through Myanmar to the Andaman Sea. The Mekong flows through Laos, Thailand, Cambodia, and southern Vietnam to the South China Sea. The Chao Phraya flows southward through Thailand to the Gulf of Thailand. The rivers’ surrounding plains are wide and very fertile.

To the south lies the Malay Peninsula, which extends about 1,200 km (about 750 mi) southwest from the Indochinese Peninsula. The Malay Peninsula comprises southern Myanmar, southern Thailand, western Malaysia, and Singapore just off the southern tip. The long, narrow peninsula is largely mountainous and covered by dense rain forest.

The Malay Archipelago forms a huge arc south and east of the peninsulas, and contains eastern Malaysia, Brunei, Indonesia, East Timor, and the Philippines. The islands are all mountainous and numerous active and extinct volcanoes are scattered throughout the archipelago. The islands are extremely fertile, well watered, and covered by rich tropical vegetation.

A.

Climate

Much of the Indochinese Peninsula experiences a typical monsoon climate, with a rainy season and a dry season. The rainy season is in summer, when moist monsoon winds blow from the sea. The areas closest to the equator have a rainy tropical climate with year-round rainfall. The Philippines and western Myanmar also have a rainy tropical climate, but with a short dry season. Much of northern Myanmar, Laos, and Vietnam have a humid subtropical climate with a winter dry season. Most of the islands and coastal areas of Southeast Asia receive 2,000 mm (80 in) or more of rain annually, and there may be twice as much on some of the mountain slopes. Some interior areas of Myanmar and Thailand, where the mountains form a barrier against the rain-bearing winds, receive less than 1,000 mm (40 in) a year.

B.

Vegetation

Most of Southeast Asia is covered with tropical forests. There are rain forests where annual rainfall exceeds 2,000 mm (80 in) and is distributed throughout the year. Monsoon forests or grasslands with scattered trees occur in areas where rainfall is seasonal. The monsoon forests, which are more open than the rain forests, consist largely of trees that lose their leaves during the dry season. Mangrove forests or coconut palms are often found along the coast.

C.

Soils and Farming

The soils of Southeast Asia’s volcanic islands and river floodplains and deltas are fertile. Rice is the leading crop in most of the region. Other food crops of Southeast Asia include corn, sweet potatoes, cassava, and fruits. Although much of the rest of the region is covered with dense vegetation, the soils of the forests and highlands are generally not fertile. High temperatures and high precipitation leach out the valuable minerals and break down the humus formed by decaying vegetable matter. Many of these soils cannot support cultivated crops for more than a short time.

D.

Natural Resources

Southeast Asia is rich in mineral resources. A significant portion of the world’s tin comes from Southeast Asia, particularly from Indonesia. Petroleum, coal, copper, and gold are also mined extensively in the region.

The region’s dense forests also yield important resources. Important hardwoods logged include teak, ebony, and mahogany. Other forest products that are commercially exploited and exported are sandalwood (a soft, fragrant wood), coconuts, and abaca (a fiber used to make Manila hemp).