Mekong river basin

Mekong River is the longest river in Southeast Asia, with a total length of about 4,908 kilometers and a total drainage area of 8 1. 1.000 square kilometers. It is the ninth longest river in the world, the seventh longest river in Asia and the largest river in Southeast Asia. Originated in Qinghai Province, China, it flows through Xizang Autonomous Region and Yunnan Province, then becomes part of the international boundary between Myanmar and Laos, Laos and Thailand, flows through Laos, Cambodia and Vietnam, and then flows into the South China Sea in the south of Ho Chi Minh City (Saigon). Vientiane, the capital of Laos, and Phnom Penh, the capital of Cambodia, are on the shore. About three-quarters of the Mekong River basin flows through five downstream countries-Myanmar, Laos, Thailand, Cambodia and Vietnam.

After the Lancang River flows out of China, it is called the Mekong River, accounting for 77.8% of the total flow area of the Mekong-Lancang River, including almost all parts of Laos, Cambodia and Thailand, the delta area of Vietnam and some rivers in central Korea, with an average gradient of about 0. 16‰.

The second largest international river flows into the South China Sea of the Pacific Ocean. The main tributaries are Nanta River, Nanwujiang River, Nankang River, South Russia River, Nantun River, Bangfei River, Sebangheng River, Menghe River, Sanghe River and tonle sap river, among which Menghe River is the largest tributary. The downstream residents account for about 1/3 of the population of the four countries along the river. Almost all people are engaged in agriculture, and rice is the main crop. The most densely populated areas are the Delta and the Nakhon Ratchasima Plateau. The population of some cities has been growing rapidly, mainly through emigration to cities. There is no racial relationship between the populations in the basin. Ethnic minorities include Han and Tibetan in the upper Mekong River, including Karen and Miao, and Khmer, Zhan, Thai, Meng and Vietnamese in the lower Mekong River. Vietnamese are concentrated in the delta, while Khmer and Thai are widely distributed in the downstream.