River systems of Thailand

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A topographic map of Thailand demonstrating primarily the Chao Phraya River System in the central plains and branches of the Mekong River System flowing west to east. Thailand Topography.png
A topographic map of Thailand demonstrating primarily the Chao Phraya River System in the central plains and branches of the Mekong River System flowing west to east.

Thailand has 22 river basins with 254 sub-basins. Rainwater is one of the most important sources of water. Thailand's water resource per capita is less than that of other countries in the region. [1]

Contents

The two principal river systems of Thailand are the Chao Phraya and the Mekong. Together, these rivers support the irrigation for Thailand's agricultural economy.

In addition to these two large systems, there are a number of other river systems and individual rivers which drain the lands within Thailand's borders into the Gulf of Thailand and the Andaman Sea. One-third of the nation's rivers flow into the Mekong. [1] The Mekong is the only river system in Thailand which drains into the South China Sea.

Chao Phraya River system

Chao Phraya River System. Chaophrayarivermap.png
Chao Phraya River System.
Thw Chao Phraya River in Bangkok Lunch at Rongros, Bangkok (Jan 2021) - img 05.jpg
Thw Chao Phraya River in Bangkok

The Chao Phraya River system is the main river system of Thailand, as its basin defines much of the region of central Thailand. The Chao Phraya River begins at the confluence of the Ping and Nan Rivers at Nakhon Sawan (also called Pak Nam Pho) in Nakhon Sawan Province. It then flows from north to south for 372 kilometres (231 mi) from the central plains through Bangkok to the Gulf of Thailand. The Chao Phraya River Catchment area is approximately 17,270 km2. [2]

In Chai Nat, the river splits into the main river course and the Tha Chin River, which then flows parallel to the main river and exits to the Gulf of Thailand about 35 kilometres (22 mi) west of Bangkok in Samut Sakhon. In the low alluvial plain which begins below the Chai Nat Dam, many small canals ( khlong ) split off from the main river. The khlong are used for the irrigation of the region's rice paddies.

Tributaries

The principal tributaries of the Chao Phraya River are the Pa Sak River, the Sakae Krang River, the Nan River (along with its principal confluent the Yom River), the Ping River (with its principal confluent the Wang River), and the Tha Chin River. [3] Each of these tributaries (and the Chao Phraya itself) is further tributed by additional minor tributaries often referred to as khwae. All of the tributaries, including the lesser khwae, form an extensive tree-like pattern, with branches flowing through nearly every province in central and northern Thailand. [3]

None of the tributaries of the Chao Phraya extend beyond the nation's borders. [4] The Nan and the Yom Rivers flow nearly parallel from Phitsanulok to Chumsaeng in the north of Nakhon Sawan Province. The Wang River enters the Ping River near Sam Ngao District in Tak Province.

Drainage

The expanse of the Chao Phraya River and its tributaries, i.e., the Chao Phraya river system, together with the land upon which falling rain drains into these bodies of water, form the Chao Phraya watershed. [5] The Chao Phraya watershed is the largest in Thailand, covering approximately 35 percent of the nation's area, and draining an area of 157,924 square kilometres (60,975 sq mi). [6]

Lesser Gulf river systems

There are numerous rivers which flow into the Gulf of Thailand, including a number of west coast gulf rivers, east coast gulf rivers, and rivers which drain into the gulf on the east coast of the Malay Peninsula. The following river systems, in addition to the Chao Phraya, are the most significant gulf systems in Thailand:

Bang Pakong

The Bang Pakong River is a river in eastern Thailand. The river originates at the confluence of the Confluence of Phra Prong River and the Hanuman River near Kabin Buri District. It empties into the Gulf of Thailand in the northeastern tip of the Bay of Bangkok. The Bang Pakong's principal tributaries are the Nakhon Nayok River and the Tha Lat River. The watershed of the Bang Pakong is about 17,900 square kilometres (6,900 sq mi).

Phetchaburi

The Phetchaburi River is a river in western Thailand. It originates in Kaeng Krachan National Park, Kaeng Krachan District and flows through Tha Yang, Ban Lat, Mueang Phetchaburi and empties into the Bay of Bangkok in Ban Laem District. It is 210 kilometres (130 mi) long, most of which is in Phetchaburi Province.

Mae Klong

The Mae Klong River is a river in western Thailand. The river begins at the confluence of the Khwae Noi or Khwae Sai Yok and the Khwae Yai River or Khwae Si Sawat in Kanchanaburi, passes through Ratchaburi Province and empties into the Gulf of Thailand in Samut Songkhram.

Pran Buri

The Pran Buri River is in Prachuap Khiri Khan Province, on the Kra Isthmus of the Malay Peninsula. The Pran Buri River originates in southern part of the Kaeng Krachan National Park, and after 130 kilometres (81 mi) empties into the Gulf of Thailand. The only town on the river's course is Pran Buri, the center of Pran Buri District. The watershed of the Pran Buri River has an area of about 2,000 square kilometres (770 sq mi).

Khlong Kui

The Khlong Kui River drains into the Gulf of Thailand from the Malay Peninsula in Thailand. It flows through Ban Pong Kasang and Ban Thung Faek, Kui Buri District, Prachuap Khiri Khan Province. [3]

Tapi and Phum Duang

The Tapi River with its main tributary Phum Duang drain the area of Surat Thani Province. The total watershed of the river system is about 11,500 square kilometres (4,400 sq mi).

Pattani

The Pattani River is the longest of all Thai rivers on the Malay Peninsula with a total length of 214 kilometres (133 mi).

Mekong River system

The Mekong River system Mekong system color.png
The Mekong River system

The Mekong River, one of the world's major rivers, drains into the South China Sea. It is the 11th-longest river in the world, and the 12th-largest by volume (discharging 475 cubic kilometres (114 cu mi) of water annually). Its estimated length is 4,880 kilometres (3,030 mi), and it drains an area of 810,000 square kilometres (310,000 sq mi). [7]

From the Tibetan Plateau it runs through China's Yunnan Province, Myanmar, Thailand, Laos, Cambodia, and Vietnam. All except China and Myanmar are members of the Mekong River Commission. The extreme seasonal variations in flow and the presence of rapids and waterfalls have made navigation extremely difficult. Approximately half the river's length is in China, where it is known as the Lancang Jiang (澜沧江 Láncāng Jiāng) or Meigong in Chinese (Chinese :湄公河; pinyin :Méigōng Hé).

The river forms the border between Myanmar and Laos for 200 kilometres (120 mi), at the end of which it meets the tributary Ruak River at the Golden Triangle. This point also marks the division between the Upper and Lower Mekong.

The river then divides Laos and Thailand, before a stretch passing through Laos alone. It is called Maenam Khong in both Lao and Thai (แม่น้ำโขง). The river again marks the Lao-Thai border in the stretch which passes Vientiane, followed by a short stretch through Laos alone.

In Cambodia, the river is called the Mékôngk or Tonle Thom ("great river"). Just above Phnom Penh is the confluence with the Tonle Sap, the main Cambodian tributary. Below Phnom Penh, it divides into the Bassac and the Mekong proper, which both flow into the Mekong Delta in Vietnam. In Vietnamese, the river as a whole is known as Mê Kông. In Vietnam, the river divides into two major branches, the Tiền Giang (Front River) and Hậu Giang (Back River). These in turn enter the South China Sea through nine estuaries.

Thai tributaries of the Mekong

The following are the principal tributaries of Mekong River which flow through Thailand (tributaries entirely outside the Thai border not shown).

Drainage

The Mekong drains a considerable portion of northeast Thailand. In terms of Thai territory drained, it is second only to the Chao Phraya system.

Salawin River System

The Salawin River system. Salween watershed.png
The Salawin River system.

The Salawin River rises in Tibet (Tibetan: རྒྱལ་མོ་རྔུལ་ཆུ།) after which it flows through Yunnan, where it is known as the Nujiang River (Chinese :怒江; pinyin :Nù Jiāng), although either name can be used for the whole river. The river is 2,815 kilometres (1,749 mi) long. It then leaves China and meanders through Myanmar (where it is known as the Thanlwin) and Thailand (where it is known as the Salawin, Thai: สาละวิน) on its way to emptying into the Andaman Sea by Mawlamyaing (Moulmien). [8]

Thai tributaries

The principal tributaries of the Salawin which flow through Thailand are the Moei River and the Pai River.

Other Andaman Sea rivers

In addition to the Salween River, there are a number of rivers which drain into the Andaman Sea from the west coast of the Malay Peninsula. None of them are extensive enough to be considered river systems.

Related Research Articles

<span class="mw-page-title-main">Geography of Thailand</span>

Thailand is in the middle of mainland Southeast Asia. It has a total size of 513,120 km2 (198,120 sq mi) which is the 50th largest in the world. The land border is 4,863 km (3,022 mi) long with Myanmar, Cambodia, Laos and Malaysia. The nation's axial position influenced many aspects of Thailand's society and culture. It controls the only land route from Asia to Malaysia and Singapore. It has an exclusive economic zone of 299,397 km2 (115,598 sq mi).

<span class="mw-page-title-main">Chao Phraya River</span> Major river in Thailand

The Chao Phraya is the major river in Thailand, with its low alluvial plain forming the centre of the country. It flows through Bangkok and then into the Gulf of Thailand.

<span class="mw-page-title-main">Chonburi province</span> Province of Thailand

Chonburi is a province of Thailand (changwat) located in eastern Thailand. Its capital is also named Chonburi. Neighbouring provinces are Chachoengsao, Chanthaburi, and Rayong, while the Bay of Bangkok is to the west. Pattaya, a major tourism destination in Thailand, is located in Chonburi, along with Laem Chabang, the country's primary seaport. The population of the province has grown rapidly and now totals 1.7 million residents, although a large portion of the population is floating or unregistered. The registered population as of 31 December 2018 was 1.535 million.

<span class="mw-page-title-main">Northern Thailand</span> Region in Chiang Mai


Northern Thailand, or more specifically State of Lanna, is geographically characterised by several mountain ranges, which continue from the Shan Hills in bordering Myanmar to Laos, and the river valleys which cut through them. Though like most of Thailand, it has a tropical savanna climate, its relatively high elevation and latitude contribute to more pronounced seasonal temperature variation, with cooler winters than the other regions.

<span class="mw-page-title-main">Bang Pakong River</span> River in Thailand

The Bang Pakong is a river in east Thailand. The river originates at the confluence of the Phra Prong River and the Hanuman River near Kabin Buri, Prachinburi Province. It empties after 231 kilometres into the Gulf of Thailand at the northeastern tip of the Bay of Bangkok. The watershed of the Bang Pakong is about 17,000 square kilometres (6,600 sq mi). The river powers a power station near its mouth, near Highway 7.

The Pran Buri River is a river in Prachuap Khiri Khan Province, Thailand, on the Kra Isthmus of the Malay Peninsula. The Pran Buri River originates in southern part of the Kaeng Krachan National Park in the Tenasserim Hills and after 130 kilometres (81 mi) empties into the Gulf of Thailand. The only town along the river course is Pran Buri, the center of the Pran Buri District. The watershed of the Pran Buri River has an area of about 2,000 square kilometres (770 sq mi).

<span class="mw-page-title-main">Wang River</span> River in Lampang Province, Thailand

The Wang River is a river in northern Thailand.

<span class="mw-page-title-main">Tha Chin River</span> Distributary of the Chao Phraya River

The Tha Chin river is a distributary of the Chao Phraya river, Thailand. It splits in the province of Chai Nat and then flows west from the Chao Phraya through the central plains, until it empties into the Gulf of Thailand in Samut Sakhon Province.

<span class="mw-page-title-main">Ping River</span> Major Tributary of the Chao Phraya River

The Ping River, along with the Nan River, is one of the two main tributaries of the Chao Phraya River. It originates at Doi Thuai in the Daen Lao Range, in Chiang Dao district, Chiang Mai province. After passing Chiang Mai, it flows through the provinces of Lamphun, Tak, and Kamphaeng Phet. At the confluence with the Nan River at Nakhon Sawan, it forms the Chao Phraya River.

<span class="mw-page-title-main">Nan River</span> Mahor tributary of the Chao Phraya River

The Nan River is a river in Thailand. It is one of the most important tributaries of the Chao Phraya River.

<span class="mw-page-title-main">Yom River</span> River in Thailand

The Yom River is a river in Thailand. It is the main tributary of the Nan River. The Yom River has its source in the Phi Pan Nam Range in Pong District, Phayao Province. Leaving Phayao, it flows through Phrae and Sukhothai as the main water resource of both provinces before it joins the Nan River at Chum Saeng District, Nakhon Sawan Province.

<span class="mw-page-title-main">Sakae Krang River</span> River in Thailand

The Sakae Krang River is a tributary of the Chao Phraya River. It originates in Mae Wong National Park, Nakhon Sawan Province. It is 225 kilometres (140 mi) long, with most of its length in Uthai Thani Province. It joins the Chao Phraya River in Uthai Thani city near the Wat Tha Sung.

<span class="mw-page-title-main">Chat Trakan district</span> District in Phitsanulok, Thailand

Chat Trakan is the northernmost district (amphoe) of Phitsanulok province, central Thailand.

The Khwae Noi River is a river in northern Thailand. It shares the same name as another river in Thailand, the popular tourist attraction also known as "The River Kwai." These are two distinct bodies of water.

The Wat Ta Yom River is a tributary of the Nan River in Thailand.

The Hanuman River or Khwae Hanuman (แควหนุมาน) originates in South San Kamphaeng Mountain Range, the Khao Yai National park. It begins at the confluence of many small tributaries at Samphanta Subdistrict, Na Di District, Prachin Buri Province. It flows southward and joins the Phra Prong River to become the Bang Pakong River in Kabin Buri district, Prachinburi Province. The river is 25 kilometres (16 mi) long.

<span class="mw-page-title-main">Phitsanulok</span> City Municipality in Thailand

Phitsanulok is a city, municipality, the capital and the largest populated place of the Thai province of Phitsanulok. It is also the headquarters of the Mueang Phitsanulok District. In 2022, it had a population of 62,000, making it the second–largest cities by population in the lower northern Thailand. The city is one of the centre of Thailand's tourism industry, and it is a historic city in the country.

References

  1. 1 2 THAILAND ENVIRONMENT MONITOR Integrated Water Resources Management: A Way Forward (PDF) (63368 ed.). The World Bank. June 2011. Retrieved 26 November 2016.
  2. Chaiwongsaen, Nikhom; Nimnate, Parisa; Choowong, Montri (2019). "Morphological Changes of the Lower Ping and Chao Phraya Rivers, North and Central Thailand: Flood and Coastal Equilibrium Analyses". Open Geosciences. 11 (1): 152–171. doi: 10.1515/geo-2019-0013 .
  3. 1 2 3 Royal Irrigation Department River Gauges Report Archived 2009-08-14 at the Wayback Machine
  4. Google Earth
  5. River and Watershed Facts on the Chao Phraya
  6. Basins of Thailand Archived 2008-02-22 at the Wayback Machine
  7. Source of the Mekong River (Langcang Jiang)
  8. "Tibetan Ecology Foundation-Khoryug". Archived from the original on 20 April 2012. Retrieved 25 April 2012.