Posted on Fri, May. 23, 2008

''The river knows everything,'' the Nobel Prize winning author Herman Hesse once wrote. ''One can learn everything from it.'' Up the Yangtze, director Yung Chang's lovely, engrossing documentary largely set aboard a cruise ship sailing on the titular river, doesn't teach you everything, exactly. But its range of subjects and emotions cuts a surprisingly wide swath.

''Like turning the Grand Canyon into a lake'' is how Chang, who also narrates, compares the effects of China's controversial Three Gorges Dam on the surrounding 400 square miles. Measuring more than a mile in width and 600 feet high, the effect of the dam on the area is mind-boggling, beginning with the displacement of two million people who live there.

Chang delves into the history of the project and its consequences on the region by focusing on a luxury ''farewell cruise'' on the river, which courses through areas that will soon be submerged. Populated by wealthy North American and European tourists, the ship also employs two young locals: Cindy, the daughter of poor, illiterate parents, who dreams of going to college but is forced to work to help her family, and Jerry, a brash, middle-class young man who uses his cockiness to secure tips from the passengers.

By focusing on his two young protagonists, Chang is able to explore the cultural differences between China and the rest of the world, resulting in sequences that are alternately humorous and eye-opening. But Up the Yangtze's main tone is one of a melancholy mournfulness for the unimaginable scope of what is soon to be lost, and never regained, in the name of progress.

With: ''Cindy'' Yu Shui, ''Jerry'' Chen Bo Yu

Writer-director: Yung Chang

Producers: Mila Aung-Thwin, Germaine Ying-Gee Wong, John Christou

A Zeitgeist Films release. Running time: 93 minutes. No offensive material. In English, Mandarin and Sichuan with English subtitles. In Miami-Dade: Cosford.