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. The Mekong is the only river system in Thailand which drains into the South China Sea.

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 river at Nakhon Sawan (also called Pak Nam Pho) in the 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. In Chainat, the river splits into the main river course and the Tha Chin river, which then flows parallel to the main river and exits to Gulf of Thailand at about 35 kilometres (22 mi) west of Bangkok in Samut Sakhon. In the low alluvial plain which begins below the Chainat dam, many small canals (khlong) split off from the main river. The khlong are used for the irrigation of the region's rice paddies.

Thailand ( /ˈtaɪlænd/ TY-land or /ˈtaɪlənd/;Thai: ประเทศไทย, RTGS: Prathet Thai), officially the Kingdom of Thailand (Thai: ราชอาณาจักรไทย, RTGS: Ratcha Anachak Thai; IPA: [râːt.tɕʰā ʔāːnāːtɕàk tʰāj] ( listen)), formerly known as Siam (Thai: สยาม; RTGS: Sayam), is a country located at the centre of the Indochina peninsula in Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and the southern extremity of Burma. Its maritime boundaries include Vietnam in the Gulf of Thailand to the southeast, and Indonesia and India in the Andaman Sea to the southwest.

The country is a constitutional monarchy, headed by King Rama IX, the ninth king of the House of Chakri, who, having reigned since 1946, is the world's longest-serving head of state and the longest-reigning monarch in Thai history. The king of Thailand is titled Head of State, Head of the Armed Forces, the Upholder of the Buddhist religion, and the Defender of all Faiths.

In geomorphology, a drainage system is the pattern formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by the topography of the land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land. Geomorphologists and hydrologists often view streams as being part of drainage basins. A drainage basin is the topographic region from which a stream receives runoff, throughflow, and groundwater flow. Drainage basins are divided from each other by topographic barriers called a watershed. A watershed represents all of the stream tributaries that flow to some location along the stream channel. The number, size, and shape of the drainage basins found in an area varies and the larger the topographic map, the more information on the drainage basin is available.

Drainage systems can fall into one of several categories, depending on the topography and geology of the land:

Dendritic drainage systems (from Greek δενδρίτης, dendrites, "of or pertaining to a tree") are the most common form of drainage system. In a dendritic system, there are many contributing streams (analogous to the twigs of a tree), which are then joined together into the tributaries of the main river (the branches and the trunk of the tree, respectively). They develop where the river channel follows the slope of the terrain. Dendritic systems form in V-shaped valleys; as a result, the rock types must be impervious and non-porous.

Yingluck Shinawatra (Thai: ยิ่งลักษณ์ ชินวัตร, RTGS: Yinglak Chinnawat, Thai pronunciation: [jîŋ.lák tɕʰīn.nā.wát]; born 21 June 1967), or nickname Pu (Thai: ปู; Thai pronunciation: [pūː ]; "crab"), is a Thai businesswoman and politician, member of the Pheu Thai Party, who became the 28th and current Prime Minister of Thailand following the 2011 general election. Yingluck is Thailand's first female Prime Minister and at 44 is the youngest Prime Minister of Thailand in over 60 years.

Born in Chiang Mai province, Yingluck Shinawatra earned bachelor's degree from Chiang Mai University and master's degree from Kentucky State University, both in public administration. She became an executive in the businesses founded by her elder brother, Thaksin Shinawatra, and later became the president of property developer SC Asset and managing director of Advanced Info Service. Meanwhile, her brother Thaksin became Prime Minister, was overthrown in a military coup, and went into self-imposed exile after a tribunal convicted him of abuse of power.