Long-term Evolution Patterns of Qingdao City based on Historical Maps and Remote Sensing Images

Current studies on urban evolution heavily rely on either remote sensing imagery or historical maps, seldom integrating both sources. Additionally, there is a scarcity of research on urban long-term evolution exceeding half a century. This study employs an innovative approach that combines historical maps and remote sensing imagery. Pre-remote sensing era, data from modern historical maps were extracted to reveal urban evolution patterns. In the 1960s-1980s, using early panchromatic remote sensing imagery due to limited urban maps in China, the study explored urban evolution. Post-1980s, higher-resolution Landsat series imagery was utilized. The integration of historical maps and remote sensing imagery forms a coherent, long-term urban evolution sequence, facilitating the discovery of comprehensive urban change patterns. The study involves extracting construction areas for urban expansion analysis, employing a combination of visual interpretation and random forest extraction methods for enhanced efficiency and accuracy.