Changes in the Geomorphological Characteristics of Tangeumdae due to Local Cultural Heritage and Ancient Maps

This study discussed the geomorphologic characteristics and changes of Tangeumdae and its vicinity, a local cultural heritage site. The region features river terraces, floodplains, and hills, and their geomorphologic changes are closely linked to human settlement. The high-level river terrace was historically used for the Tangeumdae battlefield in the past and supports various human land uses, including agricultural acitivities. Since the Bronze Age, full-fledged human activities were carried out in the low and high-level surfaces, hilly areas, and valley plains of the river terrace system in Tangeumdae, while the floodplain remained undeveloped in early times. However, beginning from the Goryeo Dynasty, some of the floodplain began to be more actively utilized with the growing importance of water transportation. In the 20th century, major flood events in the 1920s and 1930s caused the Hangang River and Dalcheon River to change into braided streams. As a result, the Tangeumdae area was geographically isolated and the sand deposition area was substatially expanded along the rivers. Since the 1970s, artificial embankments have been built and reinforced. Furthermore, the construction of Chungju Dam and Chungju Coordinate-Lake Dam in the 1980s lead to a rise in water level, submerging much of the historical lakeside landscape. Meanwhile, maintenance and reorganization of the Chungjucheon Stream embankment allowed Chungju City to expand into the floodplain, resulting in the modern geomorphological landscape seen today.