The Khorat Plateau also Korat Plateau, is a plateau in the northeastern (Isan) region of Thailand, named for the short form of Nakhon Ratchasima

Nakhon Ratchasima

Nakhon Ratchasima or is a city in the north-east of Thailand and gateway to Isan. It is the capital of the Nakhon Ratchasima Province and Nakhon Ratchasima district...

, an historical stronghold controlling access to and from the plateau.

Geography

The average elevation is 200 m and it covers an area of about 155,000 km². The saucer-shaped plateau is tilted towards the south-east, and is drained by the Mun

Mun River

The Mun River , sometimes spelled Moon River, is a tributary of the Mekong river. It carries approximately 21,000 cubic kilometres of water per year.-Geography:...

 and Chi river

Chi River

The Chi River is the longest river in Thailand; it extends 765 km, but carries less water than the second longest river, the Mun. In the Isan dialect of this region, and also in the adjacent language Lao, the name of the river is actually pronounced "Nam Si" but the transliteration Chi...

s, tributaries to the Mekong

Mekong

The Mekong is a river that runs through China, Burma, Laos, Thailand, Cambodia and Vietnam. It is the world's 10th-longest river and the 7th-longest in Asia. Its estimated length is , and it drains an area of , discharging of water annually....

, the north eastern boundary of the area. It is separated from Central Thailand

Central Thailand

Central Thailand is a region of Thailand, covering the broad alluvial plain of the Chao Phraya River. It is separated from North-East Thailand by the Phetchabun mountain range, and another mountain range separates it from Myanmar to the west. In the north it gently changes into the more hilly...

 by the Phetchabun mountain range

Phetchabun Mountains

The Phetchabun mountains are a mountain range in Thailand.-Geography:It extends in a roughly north-south direction, and separates the broad Chao Phraya river valley of central Thailand from the Khorat Plateau of northeast Thailand...

 and the Sankamphaeng Range, the southern prolongation of the Dong Phaya Yen mountains

Dong Phaya Yen mountains

Dong Phaya Yen is a mountain range in central Thailand.-Description:Dong Phaya Yen is the southeastern extension of the Phetchabun mountains, dividing the Chao Phraya river valley of Central Thailand and the Khorat Plateau of the northeast...

; and from Cambodia

Cambodia

Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...

 by the Dongrek mountains to the south, all of which make access to the plateau difficult.

These together with the Truong Son Range in the north-east catch a lot of the rainfall, so the South-West monsoon

Monsoon

Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation, but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea...

 has much lower intensity then in other regions—the mean annual rainfall in Nakhon Ratchasima is about 1150 mm, compared with 1500 mm in Central Thailand. The difference between dry and wet season is much stronger, which makes the area less fertile for rice

Rice

Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

. The portion known as Tung Kula Rong Hai

Tung Kula Rong Hai

Tung Kula Rong Hai is a large plateau in Northeastern Thailand. Its area has size around 2 million rais . It is located in the provinces of Surin, Maha Sarakham, Buriram, Sisaket and Roi Et....

 was once exceptionally arid

Arid

A region is said to be arid when it is characterized by a severe lack of available water, to the extent of hindering or even preventing the growth and development of plant and animal life...

.

Geology

The plateau uplifted from an extensive plain

Plain

In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...

 composed of remnants of the Cimmerian microcontinent

Cimmeria (continent)

Cimmeria was an ancient microcontinent that existed about 200 million years ago. It rifted north from Gondwana during the Late Carboniferous and collided against eastern Laurasia during the Late Triassic together with the Chinese continents. The collision created new mountain ranges between...

, and terrane

Terrane

A terrane in geology is short-hand term for a tectonostratigraphic terrane, which is a fragment of crustal material formed on, or broken off from, one tectonic plate and accreted or "sutured" to crust lying on another plate...

s such as the Shan–Thai Terrane

Shan–Thai Terrane

The Shan–Thai terrane rifted from Australia in the Permian and collided with the Indochina terrane in the Triassic. It extends from from Malaysia, through peninsular Thailand, Myanmar, West Yunnan, to Lhasa....

, either late in the Pleistocene

Pleistocene

The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 or early in the Holocene

Holocene

The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

 Epoch

Epoch

-An epoch :* Epoch , a moment in time chosen as the origin of a particular era* Epoch or geologic epoch, a span of time smaller than a "period" and larger than an "age"...

, approximately Year 1 of the Holocene calendar

Holocene calendar

The Human Era, also known as the Holocene calendar or Holocene era , is a year numbering system that adds exactly 10,000 years to the currently world-dominant Anno Domini and Common Era system, placing its first year near the beginning of the Holocene epoch and the Neolithic revolution...

. Much of the surface of the plateau was once classified as laterite

Laterite

Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...

, and layers that can easily be cut into brick-shaped blocks are still so called, but the classification of soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

s as various types of oxisol

Oxisol

Oxisols are an order in USDA soil taxonomy, best known for their occurrence in tropical rain forest, 15-25 degrees north and south of the Equator. Some oxisols have been previously classified as laterite soils.-Formation:...

s is more useful for agriculture

Agriculture

Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

. Oxisols of the type called rhodic ferralsols, or Yasothon

Yasothon Province

Yasothon is one of the provinces of Thailand, located in the North-East of Thailand on the Chi River. Neighboring provinces are Mukdahan, Amnat Charoen, Ubon Ratchathani, Sisaket and Roi Et.-Geography:...

 soils, formed under humid tropical conditions in the early Tertiary

Tertiary

The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...

. When portions of the plain uplifted as a plateau, these relict

Relict

A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....

 soils, characterized by a bright red color, wound up on upland

Highland (geography)

The term highland or upland is used to denote any mountainous region or elevated mountainous plateau. Generally speaking, the term upland tends to be used for ranges of hills, typically up to 500-600m, and highland for ranges of low mountains.The Scottish Highlands refers to the mountainous...

s in a great semicircle around the southern rim. These soils overlie associated gravel

Gravel

Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

 horizon

Soil horizon

A soil horizon is a specific layer in the land area that is parallel to the soil surface and possesses physical characteristics which differ from the layers above and beneath. Horizon formation is a function of a range of geological, chemical, and biological processes and occurs over long time...

s cleared of sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

 by field

Field (agriculture)

In agriculture, the word field refers generally to an area of land enclosed or otherwise and used for agricultural purposes such as:* Cultivating crops* Usage as a paddock or, generally, an enclosure of livestock...

 termites, in a prolonged and still on-going process of bioturbation

Bioturbation

In oceanography, limnology, pedology, geology , and archaeology, bioturbation is the displacement and mixing of sediment particles and solutes by fauna or flora . The mediators of bioturbation are typically annelid worms , bivalves In oceanography, limnology, pedology, geology (especially...

. Xanthic ferralsols of the Khorat

Nakhon Ratchasima Province

Nakhon Ratchasima or , often shortened to Korat or Khorat , is one of the north-eastern provinces of Thailand...

 and Udon

Ubon Ratchathani Province

-History:The area was part of the Khmer Empire. Before the late eighteenth century, this area evidently was outside Siamese or Thai Ayutthaya Kingdom....

 Series, characterized by a pale yellow to brown color, developed in midlands in processes still under investigation; as are those forming lowland

Lowland

In physical geography, a lowland is any broad expanse of land with a general low level. The term is thus applied to the landward portion of the upward slope from oceanic depths to continental highlands, to a region of depression in the interior of a mountainous region, to a plain of denudation, or...

 soils resembling European brown soil

Brown earth

Brown earth is a type of soil. Brown earths are mostly located between 35° and 55° north of the Equator. The largest expanses cover western and central Europe, large areas of western and trans-Uralian Russia, the east coast of America and eastern Asia. Here, areas of brown earth soil types are...

s.

Archeology

Many of the Prehistoric Thailand

Prehistoric Thailand

Prehistoric Thailand may be traced back as far as 1,000,000 years ago from the fossils and stone tools found in northern and western Thailand, an archaeological site in Lampang, northern Thailand. Homo erectus fossils, Lampang Man, dating back to between 1,000,000 – 500,000 years, have been...

 sites are sited on the plateau. The World Heritage

World Heritage Site

A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...

 Ban Chiang

Ban Chiang

Ban Chiang is an archeological site located in Nong Han district, Udon Thani Province, Thailand. It has been on the UNESCO world heritage list since 1992....

 archeological site, discovered in 1966, yielded evidence of bronze

Bronze

Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive. It is hard and brittle, and it was particularly significant in antiquity, so much so that the Bronze Age was named after the metal...

 making beginning circa 2000 BC, which lacks evidence of weaponry so often associated with the Bronze Age

Bronze Age

The Bronze Age is a period characterized by the use of copper and its alloy bronze as the chief hard materials in the manufacture of some implements and weapons. Chronologically, it stands between the Stone Age and Iron Age...

 in Europe and the rest of the world. The site appears to have once been part of a broader culture, until abandoned circa 200 AD, not resettled until the early 19th century. None Nok Tha in the Phu Wiang District of Khon Kaen yielded evidence of an Iron Age settlement dating from 1420 to 50 BC.

The region was once under the suzerainty

Suzerainty

Suzerainty occurs where a region or people is a tributary to a more powerful entity which controls its foreign affairs while allowing the tributary vassal state some limited domestic autonomy. The dominant entity in the suzerainty relationship, or the more powerful entity itself, is called a...

 of the Dvaravati

Dvaravati

The Dvaravati period lasted from the 6th to the 13th centuries. Dvaravati refers to both a culture and a disparate conglomerate of principalities.- History :...

, and later under that of the Khmer Empire

Khmer Empire

The Khmer Empire was one of the most powerful empires in Southeast Asia. The empire, which grew out of the former kingdom of Chenla, at times ruled over and/or vassalized parts of modern-day Laos, Thailand, Vietnam, Burma, and Malaysia. Its greatest legacy is Angkor, the site of the capital city...

, and is dotted with the ruins of Khmer resthouses located about 15 miles, or a day's walk

Walking

Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...

, apart, along Khmer highway

Ancient Khmer Highway

The Ancient Khmer Highway was a 225 km roadway going northwest between Angkor and Phimai . While it was not the only such road built by the Khmer, it was the most important one....

s. The chapels were not just places of rest, but also hospice

Hospice

Hospice is a type of care and a philosophy of care which focuses on the palliation of a terminally ill patient's symptoms.In the United States and Canada:*Gentiva Health Services, national provider of hospice and home health services...

s and libraries

Library

In a traditional sense, a library is a large collection of books, and can refer to the place in which the collection is housed. Today, the term can refer to any collection, including digital sources, resources, and services...

, and typically included a baray

Baray

A baray is an artificial body of water which is a common element of the architectural style of the Khmer Empire of Southeast Asia. The largest are the East Baray and West Baray in the Angkor area, each rectangular in shape, oriented east-west and measuring roughly five by one and a half miles....

 (pond.)

Thaification

Anouvong, the last of the kings of Lan Xang

Lan Xang

The Lao kingdom of Lan Xang Hom Kao was established in 1354 by Fa Ngum.Exiled as an infant to Cambodia, Prince Fa Ngum of Xieng Dong Xieng Thong married a daughter of the Khmer king. In 1349 he set out from Angkor at the head of a 10,000-man army to establish his own country...

 (Million Elephants) rebelled against Siamese suzerainty, and lost in a war that raged on for two years. Korat was then repopulated by forced migration

Forced migration

Forced migration refers to the coerced movement of a person or persons away from their home or home region...

 of Mekong valley Lao, with a heavy influx of voluntary Chinese

Thai Chinese

The Thai Chinese are an overseas Chinese community who live in Thailand. Thailand is home to the largest, oldest, most prominent, and most integrated overseas Chinese community in the world with a population of approximately 9.5 million people...

 migration. The plateau was claimed by Siam when France

French Third Republic

The French Third Republic was the republican government of France from 1870, when the Second French Empire collapsed due to the French defeat in the Franco-Prussian War, to 1940, when France was overrun by Nazi Germany during World War II, resulting in the German and Italian occupations of France...

 and Siam divided Lao territories following the Franco-Siamese War of 1893. Roi Et

Roi Et

Roi Et is a town in Northeastern Thailand, capital of the Roi Et Province. It covers the whole tambon Nai Mueang of Mueang Roi Et district. As of 2006 it has a population of 34,229....

 was established early in the 20th Century to further Siamese control, and to further assimilation of the population into the Kingdom.

Khon Kaen

Khon Kaen

Khon Kaen is a city in Isan, Thailand. It is also the capital of Khon Kaen province and the Khon Kaen district.-Geography and demography:Khon Kaen is located in the Khorat Plateau, in the central-northwestern area of Isaan...

 (Heartwood) was established in the 20th century as the commercial capital, with Khon Kaen University

Khon Kaen University

Khon Kaen University is an internationally-recognized university in Asia. It is located in the Isan region of Thailand. The university is a central hub of education in north-east Thailand.-History:...

as a central hub of education.

External links

• Khorat Plateau: A selection of articles related to Khorat Plateau from Global Oneness.