Wading further upstream, the team encounters the Tai Lu of Xishuangbanna and an ancient kinship that's being swamped
Our voyage to find the source of the Mekong brought us to Chiang Rung (Jinghong), the capital of the Xishuangbanna administrative region in Yunnan. Here we met the Dai (or Tai Lu) who share an ancient cultural, linguistic and religious kinship with their folk in Chiang Mai and other northern Thai provinces.
But here on the Mekong, life is changing. Over the past few decades, ripples of China's prosperity and tourism boom have spread to Xishuangbanna, which has become one of the country's most popular destinations. There's also been a growing feud between locals and newly arrived Han Chinese businessmen, who set up shop here to capitalise on the flood of visitors. So I was determined to gauge the impact of tourism on life in Xishuangbanna.
We were lucky indeed to stumble upon a string of interesting contacts. We met Chao Mom Khamlue, the former 41st king of the 800-year-old Xishuangbanna dynasty. We were received with a big plate of starfruit plucked from his trees at Chiang Rung palace.
The Xishuangbanna dynasty is recognised these days for estab?lishing the first Dai kingdom in Xishuangbanna, which pre-dates our own Sukhothai kingdom. Despite a generous share of palace intrigues, the throne managed to survive for almost a thousand years. Unlike Thailand, females of the dynasty were permitted to take the throne of Xishuangbanna.
We found the former king in fabulous health for an 81-year-old. He told us that he spends most of the year at his residence west of Kunming but come winter takes up residence in his palace in Xishuangbanna.
The Dai people still speak the ancient language of Tai Lu, a dialect spoken in Chiang Mai. Any ordinary Thai would understand 70 per cent of the Tai language. Identical to the Lanna script, the Tai alphabet looks nothing like written Thai, which borrows a lot from Sanskrit, Pali and Khmer. It's worth remembering that the Dai call their bedroom suam, which has somehow come to mean toilet in Thai.
One reason Chiang Rung was an important juncture on our journey was because this is where the word Mekong originated. The locals call the river Nam Khong (Mekong), which is echoed downstream through Burma, Thailand, Laos and Vietnam.
To the Chinese, it is Lancang, but there's confusion about the name's origins - does it mean "land of a million elephants" or refer to an ancient kingdom in Laos? In truth Lanna and Lancang are references to the old kingdoms that centred on Chiang Mai and Luang Prabang (or Xieng Thong).
Chiang Mai, Xieng Thong and Chiang Rung share the same cultural, religious and linguistic heritage.
But in Chiang Rung the Mekong is more than just a river.
Flowing from the north and dividing Xishuangbanna into western and eastern halves, the mighty current is called the nam mae by locals (a reversal of the Thai mae nam), or the "mother of water". Considered the origin of life, it's a source of water to drink and to wash with, a trade route and the waterway that irrigates rice paddies, fruit orchards and vegetable farms. It also teems with fish making their way downstream to lay eggs in Burma, Thailand, Laos and Vietnam.
These days Chiang Rung has emerged as a new commercial hub, with its own electricity-producing dam and a deep-water harbour for ships. But while it seems that all roads lead to Xishuangbanna, progress may have come at a cost to its much-prized ecological diversity. I saw several holes cut out of the surrounding forests, ready to be planted with rubber or coconut trees.
Meanwhile, tourism is reshaping the cultural landscape. To mop up more tourist dollars, Songkran is being distorted and abused. Traditionally held to celebrate the Dai New Year, these days water is being thrown around every day as part of cultural performances. Outsiders - mainly Han Chinese - dress up in local garb to play the part of revellers.
Other changes have a positive side. Though temples that were once free now charge an entrance fee, I was glad to discover that my money was going to help restore their old glory. The Dai's most sacred temple is Wat Ratchakhan, whose grounds dotted with coconut and palm trees would be familiar to any Thai. The oldest, however, is Wat Pathep Tawana Aram, famed for its magnificent columns.
The general impression I got, though, is that the profits from Xishuangbanna's tourism boom are being reaped by the newcomers, not the Dai. Signs that Tai Lu culture is under threat were everywhere.
The TV series "Mekong … the Untamed" is on Channel 9 every Monday at 10.15pm.