The active channel of Imjin River uses only about 150 to 200 feet of the width of the dry riverbed that it runs through, which is bordered by almost vertical rock cliffs standing approximately above the mean low water level. It gives no indication in normal times of the tremendous power it develops when in flood. During the Korean
rainy season of July and August, the Imjin becomes a raging torrent, largely confined by its steep rocky banks. Fed by its larger tributaries and many small mountain streams, it reaches flood heights of above mean water level and a velocity of 15 to . The rapid runoff of approximately 95 percent of precipitation during heavy general rains has caused Imjin, on occasion, to rise at a rate of more than six feet per hour. During the severe Korean winter, icy winds sweep down the Imjin; the sub-zero temperatures cause thick ice to form on the river. Fluctuations in the level of the river, particularly tidal action in the lower reaches, break up this ice, and large amounts of floe ice pile up against any obstacle in the channel. Many in South Korea nickname Imjin as the "River of the Dead" as in the past, large numbers of dead bodies have floated down the river from the North. The most recent occurrence was during the
major famine of the 1990s when millions of North Koreans are believed to have starved to death. == In popular culture ==