The longest river in Asia, the Yangtze River brings mixed blessings to China. Although it meets the water needs of millions of people, the river regularly overflows its banks. In the twentieth century alone, Chinese authorities estimated, the river claimed the lives of 300,000 people. To protect some 15 million residents and 3.7 million acres (roughly 14,970 square kilometers) in the lower Yangtze floodplains, China began construction on the Three Gorges Dam in 1994. Like the river itself, the dam appears to be a mixed blessing: the reservoir was expected to submerge about 632 square kilometers (244 square miles) of land and force the relocation of more than a million people. The reservoir was anticipated to submerge ecologically and culturally important sites in the three gorges—Qutang, Wu Xia, and Xiling—that were the dam’s namesake.
These images show the Yangtze River in the vicinity of the Three Gorges Dam (lower right). Landsat 7 acquired the top image on November 7, 2006, after the main wall was complete. Landsat 5 acquired the bottom image on April 17, 1987, several years before construction on the dam began. In the top image, the dam’s main wall appears as a thin, buff-colored line crossing the water. The water body balloons out markedly in the later image—evidence of the rising water level. The water has backed up and expanded tributaries well upstream of the dam (upper left of image).
