The Khorat Plateau (Thai: ที่ราบสูงโคราช) is a plateau in the northeastern Isan region of Thailand. The plateau forms a natural region, named after the short form of Nakhon Ratchasima, a historical barrier controlling access to and from the area.
Landscape of the Khorat Plateau
A map of the Khorat Plateau region
|Elevation||200 m (700 ft)|
The average elevation is 200 m and it covers an area of about 155,000 km². The saucer-shaped plateau is divided by a range of hills called the Phu Phan Mountains into two basins: the northern Sakhon Nakhon Basin, and the southern Khorat Basin. The plateau is tilted towards the southeast, and drained by the Mun and Chi Rivers, tributaries to the Mekong that forms the northeastern boundary of the area. It is separated from central Thailand by the Phetchabun Mountains and the Dong Phaya Yen Mountains in the west, the Sankamphaeng Range in the southwest and by the Dângrêk Mountains in the south, all of which historically made access to the plateau difficult.
These mountains together with the Truong Son Range in the northeast catch a lot of the rainfall, so the southwest monsoon has much lower intensity than in other regions—the mean annual rainfall in Nakhon Ratchasima is about 1,150 mm, compared with 1,500 mm in central Thailand. The difference between the dry and wet seasons is much greater, which makes the area less optimal for rice. The portion known as Tung Kula Rong Hai was once exceptionally arid.
The plateau uplifted from an extensive plain composed of remnants of the Cimmerian microcontinent, and terranes such as the Shan–Thai Terrane, either late in the Pleistocene or early in the Holocene Epoch, approximately Year 1 of the Holocene calendar. Much of the surface of the plateau was once classified as laterite, and layers that can easily be cut into brick-shaped blocks are still so called, but the classification of soils as various types of oxisols is more useful for agriculture. Oxisols of the type called rhodic ferralsols, or Yasothon soils, formed under humid tropical conditions in the early Tertiary. When portions of the plain uplifted as a plateau, these relict soils, characterized by a bright red color, wound up on uplands in a great semicircle around the southern rim. These soils overlie associated gravel horizons cleared of sand by field termites, in a prolonged and still on-going process of bioturbation. Xanthic ferralsols of the Khorat and Ubon Series, characterized by a pale yellow to brown color, developed in midlands in processes still under investigation, as are those forming lowland soils resembling European brown soils.
Many prehistoric Thailand sites are located on the plateau, with some bronze relics of the Dong Son culture having been found. The World Heritage Ban Chiang archaeological site, discovered in 1966, yielded evidence of bronze making beginning c. 2000 BCE, but lacking evidence of weaponry so often associated with the Bronze Age in Europe and the rest of the world. The site appears to have once been part of a broader culture, until abandoned c. 200 CE, not to be 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 about 1420 to 50 BCE.
The region was once under the suzerainty of the Dvaravati Kingdom, and later under the Khmer Empire. It is dotted with the ruins of Khmer resthouses located about 25 km apart, a comfortable day's walk, along the Khmer highways. The chapels were not just places of rest, but also were hospices and libraries, and typically included a baray (pond). Though Higham states, "...we remain largely unaware of the relationships between sites and the presence or otherwise of states on the Khorat plateau" during the 7th to 11th centuries. Muang Sema and Muang Fa Daet are notable though for their religious structures, including sema stones at Muang Fa Daet.:312–316
There is a paucity of information from the centuries known as the Dark ages of Cambodia, but the plateau seems to have been largely depopulated. In 1718, the first Lao muang in the Chi valley—and in fact anywhere in the interior of the Khorat Plateau—was founded at Suwannaphum District, in present-day Roi Et Province, by an official in the service of King Nokasad of the Kingdom of Champasak.
...latest Pleistocene early to the Recent regional uplifting must have occurred.
Chao Anouvong (Lao: ເຈົ້າອານຸວົງສ໌; Thai: เจ้าอนุวงศ์; RTGS: Chao Anuwong), or regnal name Xaiya Setthathirath V (Lao: ໄຊຍະເສດຖາທິຣາຊທີ່ຫ້າ; Thai: ไชยเชษฐาธิราชที่ห้า; RTGS: Chaiya Chetthathirat Thi Ha), (1767 – 1829), led the Lao rebellion (1826–28) as the last monarch of the Kingdom of Vientiane. Anouvong succeeded to the throne in 1805 upon the death his brother, Chao Inthavong (Lao: ເຈົ້າອິນທະວົງສ໌; เจ้าอินทวงศ์), Xaiya Setthathirath IV, who had succeeded their father, Ong Bun or Phrachao Siribounyasan (Lao: ພຣະເຈົ້າສິຣິບຸນຍະສາຣ; พระเจ้าสิริบุญสาร) Xaiya Setthathirath III. Anou was known by his father's regal number until recently discovered records disclosed that his father and brother had the same regal name.Eastern Thailand
Eastern Thailand is a region of Thailand bordering Cambodia on the east, Northeastern Thailand in the north, and central Thailand on the west.Geology of Thailand
The geology of Thailand includes deep crystalline metamorphic basement rocks, overlain by extensive sandstone, limestone, turbidites and some volcanic rocks. The region experienced complicated tectonics during the Paleozoic, long-running shallow water conditions and then renewed uplift and erosion in the past several million years ago.Harshavarman III
Harshavarman III (Khmer: ហស៌វរ្ម័នទី៣) was a king of Khmer who ruled from 1066 to about 1080 AD. He succeeded his elder brother Udayadityavarman II and his capital was the so-called Second Yasodharapura, which had its center in Baphuon, built by his brother, and West Baray as its principal bàrày.
His reign was upset by internal rebellions that finally he was not able to battle out. So Harshavarman III was the last ruler of his dynasty. His successor, Jayavarman VI, was an usurper who came from Phimai area, on the Khorat Plateau, in present-day Thailand. Harshavarman received the posthumous name of Sadaśivapada.He was named in stele K.908 at Preah Khan as a maternal ancestor of Jayavarman VII, even if a long dispute rose out of this issue.Between 1074 and 1080, the kingdom had to undergo the invasion by the Champa Prince Pang, a younger brother of the Champa king Harivarman IV, and himself the future king Paramabodhisattva. Sambhupra temples were destroyed and the inhabitants were taken into slavery to My Son, including the prince Sri Nandavarmadeva.In 1076, Cambodia, and Champa, was driven by the Chinese Empire in an attack against the Tonkin. The defeat of the Chinese army Đại Việt brought before the retirement of its allies.History of Laos
Evidence for modern human presence in the northern and central highlands of Indochina, that constitute the territories of the modern Laotian nation-state dates back to the Lower Paleolithic. These earliest human migrants are Australo-Melanesians — associated with the Hoabinhian culture and have populated the highlands and the interior, less accessible regions of Laos and all of South-east Asia to this day. The subsequent Austroasiatic and Austronesian marine migration waves affected landlocked Laos only marginally and direct Chinese and Indian cultural contact had a greater impact on the country.Tai and Lao people southward migration into Laos only occurred after the eighth century of the common era.
The modern nation-state Laos emerged from the French Colonial Empire as an independent country in 1953. Laos exists in truncated form from the thirteenth century Lao kingdom of Lan Xang. Lan Xang existed as a unified kingdom from 1357–1707, divided into the three rival kingdoms of Luang Prabang, Vientiane, and Champasak from 1707–1779, fell to Siamese suzerainty from 1779–1893, and was reunified under the French Protectorate of Laos in 1893. The borders of the modern state of Laos were established by the French colonial government in the late 19th and early 20th centuries.Huai Kum Dam
Huai Kum Dam, its facilities consist of a rockfill dam with clay core (35.5 metres high and 282 metres long) and a 1.2 MW semi-underground powerhouse which is 4 metres high from the ground and 11 metres down below the ground surface. The dam forms a reservoir with a storage capacity of 22 million cubic metres
The word I-san denotes vastness, which is appropriate considering that the Northeast or Khorat Plateau is bordered to the north and the east by the Mekong River and Laos, and to the south largely by Cambodia. Characterized by rolling terrain and undulating hills, the region has an arid and harsh climate, often suffering from floods and droughts. Yet the major income of the local people is from agriculture, especially rice crops. Agricultural products have dominated the region’s economy with the four main crops being rice, cassava, sugar cane and cornKhao Phra Wihan National Park
Khao Phra Wihan National Park (Thai: อุทยานแห่งชาติเขาพระวิหาร) is a protected natural area in Sisaket Province, Thailand, that contains numerous ruins of the 11th century Khmer Empire. The park lies 98 km (61 mi) south of the town of Sisaket, at the end of Thai highway 221. Sited on a red stone cliff that is part of the Dangrek mountain range on the southern edge of the Khorat Plateau, it abuts the international border between Thailand's Sisaket Province and Cambodia's Preah Vihear Province. The name of the cliff in the Royal Thai General System of Transcription is Pha Mo I Daeng (ผามออีแดง).Khorat Group
The Khorat Group is a Stratigraphic Group located within the Khorat Plateau in the Isan region of Thailand. It is Early Cretaceous in age. It consists of continental freshwater deposits largely of alternating sandstones and mudstones.. The Group is notable for its fossil content, including dinosaurs.Kuy people
The Kuy (Thai: กูย) are an indigenous ethnic group of mainland Southeast Asia. The native lands of the Kuy range from the southern Khorat Plateau in northeast Thailand east to the banks of the Mekong River in southern Laos and south to north central Cambodia. The Kuy are an ethnic minority in all three countries, where they live as "hill tribes" or Montagnards. Their language is classified as a Katuic language of the Mon-Khmer language family and, as such, is related to the Khmer language of Cambodia. The Thais, Lao, and Khmer traditionally recognize the Kuy as the aboriginal inhabitants of the region and refer to them as Khmer boran (Khmer), meaning "ancient Khmer" or Khamen pa dong (Thai: เขมรป่าดง; RTGS: Khamen pa dong, "jungle Khmer people"). The word kuy in the Kuy language means "people" or "human being"; alternate English spellings include Kui, Kuoy and Kuay, while forms similar to "Suay" or "Suei" are derived from the Thai/Lao exonyms meaning "those who pay tribute". The Kuy are known as skilled mahouts, or elephant trainers, and many Kuy villages are employed in finding, taming, and selling elephants.Lao rebellion (1826–1828)
The Lao rebellion, Siamese-Laos War of Succession (also known as Anouvong's Rebellion) was an attempt by King Anouvong (Xaiya Sethathirath V) of the Kingdom of Vientiane to end the suzerainty of Siam and recreate the former kingdom of Lan Xang. In January 1827 the Lao armies of the kingdoms of Vientiane and Champasak (ruled by Anouvong's son) moved south and west across the Khorat Plateau, advancing as far as Saraburi, just three days march from the Siamese capitol of Bangkok. The Siamese quickly mounted a counterattack, forcing the Lao forces to retreat. The Siamese continued north to defeat Anouvong's army. His rebellion had failed, which led to his capture, the destruction of his city of Vientiane in retaliation, a massive resettlement of Lao people to the west bank of the Mekong River, and direct Siamese administration of the former territories of the Kingdom of Vientiane. The rebellion was a watershed moment in the history of Southeast Asia, as it further weakened the small Lao kingdoms, perpetuated conflict between Siam and Vietnam and ultimately facilitated French involvement in Indochina in the latter half of the nineteenth century. The legacy of the Lao rebellion is controversial. It is viewed in Thailand as a ruthless and daring rebellion that had to be suppressed, and has given rise to the folk heroes such as Thao Suranari and Chao Phaya Lae. In Laos, King Anouvong is now revered as a national hero who died in pursuit of complete independence, even though he lost both his life in an ill-advised revolt against heavy odds and virtually guaranteed that the Lao-speaking provinces across the Mekong River would remain as part of Siam (now Thailand).Nakhon Ratchasima Province
Nakhon Ratchasima (Thai: นครราชสีมา, pronounced [ná(ʔ).kʰɔ̄ːn râːt.t͡ɕʰā.sǐː.māː]), often called Khorat (Thai: โคราช, pronounced [kʰōː.râːt])) (often written as Korat) is one of the Isan provinces (changwat) of Thailand's northeast corner. It is the country's largest province by area, with a population of about 2.7 million who produce about 250 billion baht in GDP, the highest in Isan. Neighbouring provinces are (clockwise, from north) Chaiyaphum, Khon Kaen, Buriram, Sa Kaeo, Prachinburi, Nakhon Nayok, Saraburi, and Lopburi.
The capital of the province is the city of Nakhon Ratchasima in Mueang Nakhon Ratchasima District, also called Khorat.Nokasad
Nokasad (full name Somdetch Brhat Chao Jaya Sri Samudra Buddhangkura; alternate names Soi Si Samout Phouthong Koun; King of Champa Nagapurisiri or Nakhon Champa Nakhaburisi) (reckoned posthumously to have been born in 1693 as Prince (Chao) Nakasatra Sungaya or Nokasat Song) was a grandson of the last king of Lan Xang, King Sourigna Vongsa; and a son-in-law of the Cambodian King Chey Chettha IV. He was made king of the southern Laotian Kingdom of Champasak from 1713 to 1737. In 1718, the first Lao muang in the Chi valley — and indeed anywhere in the interior of the Khorat Plateau — was founded at Suwannaphum District in present-day Roi Et Province by an official in the service of this king. In 1725, he turned his executive powers over to his eldest son; he died at Khorat in 1738.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. In the World Reference Base for Soil Resources (WRB), they belong mainly to the Ferralsols, but some are Plinthosols or Nitisols. Some Oxisols have been previously classified as laterite soils.Pa Hin Ngam National Park
Pa Hin Ngam (Thai: ป่าหินงาม) is a national park in Chaiyaphum Province, Thailand. "Hin ngam" means "beautiful stone", "pa" means "forest". The park got its name from the strange rock formations at the west end of the park. Erosion has carved several large rocks into striking and unusual shapes.
In 1985, the Tep Satit Forestry Department first surveyed the area, long popular with locals, and recommended its protection. In October 1986, Pa Hin Ngam Park was created, covering 10 km2 around the strange rock formations which gave the park its name. In 1993, the Forestry Department of Thailand conducted a more thorough survey including the surrounding area, and recommended that it become a national park. The national park covering 112 km2 was created on 19 September 1994, which was officially gazetted in 2007.The park is at the boundary of the Dong Phaya Yen Mountains and the Khorat Plateau. The steep cliff at the 846 m high Sut Phan Din viewpoint affords a view into a valley of the Sonthi River and the Sap Langka Wildlife Sanctuary. The name "Sut Phan Din" (สุดแผ่นดิน) means "end of land", reflecting the steepness of the cliff. This cliff also marks the watershed between the Chao Phraya and the Mekong rivers.
Lan Hin Ngam (ลานหินงาม) It was caused by the erosion of the soil and rocks into different shapes, which can be imagined as many kinds of objects and animals such as nails, radar, and hens.
Dok Kra Jiao or Bua Sawan Field (ทุ่งดอกกระเจียว หรือ ทุ่งบัวสวรรค์) Kra Jiao, a kind of curcuma, is an annual plant in the same species as ginger-galingale, scattered generally from Lan Hin Ngam to the Sut Phaendin viewpoint. Near the viewpoint is one of the fields of the Siam tulip (Curcuma alismatifolia), called "Dok Kra Jiao" (ดอกกระเจียว) in Thai. The dipterocarp forests bloom with the purple flowers at the beginning of the rainy season in July.
Sut Phaendin (สุดแผ่นดิน) is a steep cliff and the highest point of the Phang Hoei mountain range, two kilometres from the park office at 846 metres elevation. It is the cliff connecting between the central and northeastern regions.
Namtok Thep Phana (น้ำตกเทพพนา) is a medium-size waterfall originating from Huai Krachon flowing from the Phang Hoei mountain range. It has three tiers. There is water only during the rainy season.Phu Kao–Phu Phan Kham National Park
Phu Kao–Phu Phan Kham National Park (Thai: อุทยานแห่งชาติภูเก้า-ภูพานคำ) is a national park in Thailand's Khon Kaen and Nong Bua Lamphu provinces. This mountainous park, in two separate sections, encompasses part of the Ubol Ratana Dam reservoir and also features rock formations and waterfalls. The park is named for the Phu Kao and Phu Phan Kham mountain ranges of the Khorat Plateau.Phu Kradung Formation
The Early Cretaceous Phu Kradung Formation is the lowest member of the Mesozoic Khorat Group which outcrops on the Khorat Plateau in Isan, Thailand. This geological formation consists of micaceous, brown to reddish-brown siltstone beds with minor brown and grey shale and sandstone beds. Occasional lime-noduled conglomerate occurs.The Phu Kradung Formation sediments were deposited in a lake-dominated floodplain cut by meandering and occasionally braided river channels.The Phu Kradung Formation is considered, on the basis of recent vertebrae fossil discoveries, to be Late Jurassic in age. However, new palynology data suggests an age of Early Cretaceous.Dinosaur remains have been recovered from this formation, although none have yet been referred to a specific genus.Chalawan, an extinct genus of pholidosaurid mesoeucrocodylian, is currently known solely from its holotype, a nearly complete mandible collected in the early 1980s from a road-cut near the town of Nong Bua Lamphu in the upper part of the Phu Kradung Formation. This single specimen is the most well preserved vertebrate fossil that has been found from the formation. It contains a single species, Chalawan thailandicus.Phu Phan Mountains
The Phu Phan mountains (Thai: ทิวเขาภูพาน, RTGS: Thio Khao Phu Phan, pronounced [tʰīw kʰǎw pʰūː pʰāːn]) are a range of hills dividing the Khorat Plateau of the Isan region of Thailand into two basins: the northern Sakhon Nakhon Basin, and the southern Khorat Basin.The silhouette of the Phu Phan Mountains appears in the provincial seal of Kalasin since they form the northern boundary of the province.The Phu Phan mountains are among the places in Thailand more severely affected by the Illegal logging of Phayung (Siamese Rosewood) trees. Although officially a protected tree, the cutting and trading of the endangered rosewood trees has been going unabated in Thailand's mountainous forested zones, even in the protected areas. In Thailand and in China this wood is highly valued in the furniture industry.Varavudh Suteethorn
Varavudh Suteethorn, or Warawut Suteethorn (Thai:วราวุธ สุธีธร; born October 10, 1948) is a Thai geologist and palaeontologist. He is the current director of the Palaeontological Research and Education Centre, Mahasarakham University. He is best known for his work on vertebrate palaeontology in northeastern Thailand, having contributed to the discovery of many fossil taxa and dig sites in the Khorat Plateau, as a part of a long-standing collaboration between Thai and French scientists.Yasothon Province
Yasothon (Thai: ยโสธร, pronounced [já.sǒː.tʰɔ̄ːn]) is a province (changwat) of Thailand, in the northeast on the Chi River. The province was established by the revolutionary council of Field Marshal Thanom Kittikachorn, after its Announcement No. 70 which came into force on 3 March 1972.
Neighboring provinces are (from north clockwise) Mukdahan, Amnat Charoen, Ubon Ratchathani, Sisaket, and Roi Et.