Khorat Plateau

Khorat Plateau
Name	Khorat Plateau
Other name	Isan Plateau
Location	Thailand
Coordinates	16, 00, N, 102...
Elevation m	200
Elevation ft	650
Area km2	155000
Length km	400
Width km	300

Khorat Plateau. The Khorat Plateau is a vast, saucer-shaped tableland in northeastern Thailand, forming the heart of the Isan region. Bordered by the Phetchabun Mountains to the west and the Dângrêk Mountains to the south, it is drained primarily by the Mun River and Chi River systems. This region is characterized by its relatively arid climate, unique Mesozoic geology, and a rich cultural history deeply influenced by the Khmer Empire.

Geography

The plateau is bounded by the steep escarpment of the Phetchabun Mountains to the west, which separates it from the Chao Phraya River basin, and by the Dângrêk Mountains along the border with Cambodia. To the north and east, it merges into the Lao provinces of Savannakhet and Champasak. Major urban centers on the plateau include Nakhon Ratchasima, Ubon Ratchathani, Udon Thani, and Khon Kaen. The terrain is generally flat to gently rolling, with an average elevation of about 200 meters, sloping gently southeastward towards the Mekong River.

Geology

The plateau's geology is dominated by the Khorat Group, a thick sequence of non-marine Mesozoic sedimentary rocks, primarily sandstone, siltstone, and rock salt. These formations were deposited in ancient basins during the Triassic to Cretaceous periods. The region is notable for its rich fossil beds, including those of sauropod dinosaurs like Phuwiangosaurus, discovered in the Phu Wiang district. Significant potash and rock salt deposits are found within the Maha Sarakham Formation, underlying much of the area.

Climate

The climate is classified as tropical savanna climate, with a pronounced dry season. It experiences greater temperature extremes and lower humidity than other parts of Thailand due to its inland location and rain shadow effect from the western mountains. The rainy season, influenced by the southwest monsoon, typically runs from May to October, but rainfall is often erratic and insufficient. This climatic pattern contributes to frequent drought conditions, posing significant challenges for agriculture.

Hydrology

The plateau is drained by two major river systems: the Mun River and its main tributary, the Chi River. Both flow eastward, eventually joining the Mekong River along the Lao border. Key reservoirs, such as Ubolratana Dam on the Nam Pong River and Sirindhorn Dam on the Lam Dom Noi River, have been constructed for irrigation, flood control, and hydroelectric power. Despite these projects, water management remains a critical issue due to seasonal variability and high evapotranspiration rates.

History

The plateau has been inhabited since prehistoric times, with evidence from sites like Ban Chiang indicating early Bronze Age culture. It later fell under the influence of the Dvaravati culture and, most significantly, the Khmer Empire, as seen in numerous Angkor-era sanctuaries such as Phimai and Phanom Rung. Following the decline of Angkor, the area was contested between the Lao kingdoms of Lan Xang and the Ayutthaya Kingdom, eventually being incorporated into Siam under Rama I and Rama III. In the 20th century, it was a strategic region during the Franco-Thai War and the Vietnam War, hosting several United States Air Force bases like Udon Thani Air Base.

Economy

The economy is predominantly agricultural, with major crops including jasmine rice, cassava, sugarcane, and rubber. Livestock farming, particularly of swine and beef cattle, is also significant. Industrial activity is growing, centered in cities like Nakhon Ratchasima and Khon Kaen, and includes textile manufacturing, food processing, and potash mining. The region remains one of the less developed in Thailand, with lower average incomes, driving significant labor migration to Bangkok and abroad. Tourism focuses on Khmer historical sites, national parks like Khao Yai, and local Isan culture.

Category:Plateaus of Thailand Category:Geography of Isan Category:Regions of Thailand