Nan River

, very near to its source in Bo Kluea District , Thailand showing the Nan River and the Sirikit Dam The Nan River originates in the Luang Prabang Range, Nan Province. The provinces along the river after Nan Province are Uttaradit, Phitsanulok and Phichit. The Yom River joins the Nan at Chum Saeng District, Nakhon Sawan Province. When the Nan river joins together with the Ping River at Pak Nam Pho within the town Nakhon Sawan it becomes the Chao Phraya River. The Nan river runs about south. Tributaries The chief tributary of the Nan is the Yom River, which joins the Nan in Chum Saeng District in Nakhon Sawan Province. Other direct tributaries include Khlong Butsabong and Khlong San Thao of the lower Nan Basin, the Wat Ta Yom and Wang Thong Rivers which join the Nan within Phichit Province, the Khwae Noi River which joins the Nan within Phitsanulok Province, the Khlong Tron and Nam Pat, which join the Nan within Uttaradit Province, and the Lam Wa, Nam Haet, Nam Pua, Nam Yao and Nam Hao, which join the Nan within Nan Province. Waterfalls Kaeng Luang is a waterfall on the Nan River in Nan Province. ==Drainage==

Greater Nan Basin The expanse of the Nan River's tributaries, i.e. the Nan River System, together with the land upon which falling rain drains into these bodies of water, form the Greater Nan Drainage Basin, which is part of the Chao Phraya watershed. The total area drained by the Nan and its tributaries is . Basins in Thailand Much of the lower basin has perfect soil for farming. Nan Basin Most drainage analyses, however, divide the Greater Nan Basin into the Nan Basin and the Yom River Basin. Using this convention, and subtracting the of land drained by the Yom and its tributaries, the Nan basin drains a total of of land in the provinces of Phitsanulok, Phichit, Nan and Uttaradit. Basins in Thailand ==History==

Early civilizations Ancient civilizations lived in the fertile land along the Nan River and its tributaries, as is evidenced by Stone Age tools unearthed near Phitsanulok. However, these early hunter-gatherers are not likely to be ancestors of the Tai who presently inhabit the Nan basin. The human population around the Chao Phraya River and its tributaries, such as the Nan, remained sparse until late in the region’s history. The settlement of the indigenous populations of the region began around the advent of rice agriculture during the Bronze Age, and continued through the Iron Age. There is even a floating houseboat museum along the Nan in Phitsanulok, which allows tourists to experience the Nan houseboat culture first-hand. Naresuan Dam The Naresuan Dam, named after King Naresuan, was constructed throughout the span of 1976 through 1985 on the Nan River in Phitsanulok Province, north of the city of Phitsanulok, as part of the Phitsanulok Irrigation Project. ==Pollution==

Water quality in the Nan River is deteriorating from heavy bacterial contamination attributed primarily to the rapid increase of urban development in the provinces of Phitsanulok, Phichit, Nan and Uttaradit. ==References==